1. How to access Webcast?
UPDATED January 8, 2024:

In about 2013, we began simulcasting SSB Voice Radio Nets on the Internet, using Greenlight Collaboration's Webcasting platform. Greenlight had some growing pains, but it has generally performed well since it was rewritten in HTML5 several years ago. However, Greenlight Collaboration does not play well with the new iOS 17 which some folks now have on their Apple mobile devices.

We have been using Zoom internally for over 4 years (well before Zoom became a household name during the COVID pandemic). We have been conducting dual Webcats for the past few days to test whether Zoom is a suitable platform for our Webcasts, and we think it is.

Effective immediately, our morning and evening Webcasts will be on Zoom (NOT Greenlight Collaboration). Please follow the instructions below to participate in our Webcasts. If you encounter any problems (or if any of the instructions below are unclear or inaccurate), please let us know…Chris.

Instructions below are also posted on our website here:
https://www.mwxc.com/faq.php#q1
To find this, go to www.mwxc.com and click on the "FAQ" in the upper-right corner of your browser. It's FAQ#1 "How to access Webcasts?".

Tips:
Accessing the Meeting: SAVE the LINK below. Paste LINK into your web browser to access Meeting. If you are prompted for a Password, it's 010124.

At the present time, the only authentication you need is the LINK to the Meeting and maybe the Password. In the future, we will restrict access to only Subscribers of the Webcasts/SSB Nets. When we do this, we will let you know how to authenticate to access the Meeting.

If you participate in the Meeting and are not Subscribed to Webcasts/SSB Nets, please consider Subscribing. Webcasts/SSB Nets are made possible entirely by paid Subscriptions.

To ask questions: type question in the Chat Box. Please use the Public Chat, as this is what we typically monitor. If you send a Private Chat message, we will eventually see it, but we are likely to see entries faster in the Public Chat. We use headphones during our sessions, with headphone audio connected to the SSB radios, so we are not likely to hear you if you speak to us verbally on the Webcast. By default all incoming participants have their microphone muted. Please do not un-mute your microphone unless you first ask us in the text chat if we can discuss something verbally (instead of by text chat).

If you are on a low-bandwidth connection and wish to disable incoming video:
Zoom app on a computer (Windows, OSX, Linux):
1. Join meeting
2. Click View in the top-right corner, and then click Stop Incoming Video
3. To resume video, click View again and select Start Incoming Video

Zoom app on a mobile device (Android, iOS):
1. Join meeting
2. Tap the More option in your meeting controls
3. Tap Meeting Settings
4. Find and tap the toggle next to the Stop incoming video option
5. To resume videos, tap the toggle next to Stop incoming video to disable

Web browser (without installing Zoom app on your device):
1. Join meeting with the web client
2. Click the More option in the meeting controls
3. Click Stop incoming video

LINK to our ZOOM MEETING:
https://us02web.zoom.us/j/87046219306?pwd=bmJVMWxTUXJCOCsxV3VZQzJmRXhMQT09

Meeting ID: 870 4621 9306
Passcode: 010124

---

One tap mobile
+13052241968,,87046219306# US
+19292056099,,87046219306# US (New York)

---

Dial by your location
• +1 305 224 1968 US
• +1 929 205 6099 US (New York)
• +1 301 715 8592 US (Washington DC)
• +1 309 205 3325 US
• +1 312 626 6799 US (Chicago)
• +1 646 931 3860 US
• +1 689 278 1000 US
• +1 719 359 4580 US
• +1 253 205 0468 US
• +1 253 215 8782 US (Tacoma)
• +1 346 248 7799 US (Houston)
• +1 360 209 5623 US
• +1 386 347 5053 US
• +1 507 473 4847 US
• +1 564 217 2000 US
• +1 669 444 9171 US
• +1 669 900 6833 US (San Jose)

Meeting ID: 870 4621 9306

Find your local number: https://us02web.zoom.us/u/kk1axStQg

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OLD instructions for Greenlight Collaboration:

You can participate in interactive, real-time SSB Voice Nets from almost any Internet-connected device.

As of January 1, 2021 code is in HTML5, which means it works well on almost any device, including computers, tablets, phones.

As of October 22, 2023: there may be a bug which prevents Webcasts from working on iOS 17, unless you are using a VPN. Workarounds:
1. do NOT upgrade from iOS 16 to iOS 17, or
2. if you do upgrade to iOS 17, then use a VPN, or
3. access Webcasts via OSX (Mac laptop / desktop) instead of a mobile device, or any other device not using iOS 17.
We are working with Greenlight Collaboration on a fix.
4. use Zoom to participate. We will be texting Zoom in January 2024, and if it is suitable, we will migrate everyone to using Zoom (details to access via Zoom are below)

Full Multimedia (you hear us, see our webcam, and you also see our desktop. You text questions in the chat box and we answer verbally):
https://web.conferenceconsole.com/99910131
Access code = 560446 (see NOTE below)

Audio/Text chat ONLY (to conserve bandwidth, this is audio and texting only. You text questions in the chat box, and we answer verbally):
https://web.conferenceconsole.com/4634056
Access Code = 316121 (see NOTE below)

We may be able to provide a phone-in option at a later date.

Youtube VIDEO explaining how Webcasts function:
https://youtu.be/myt-iKz6Y3s

NOTE: occasionally a client will have difficulty getting the website to accept the Access Code. This typically only happens the 1st time you access the Webcast from that browser (the website remembers you after that and you no longer need the Access Code). The workaround is to try refreshing the browser and re-entering the Access Code a couple times.If copying and pasting the Access Code still fails after several attempts, please try typing the Access Code manually. The above has worked in every instance thus far.

2. Can you send forecasts to a DeLorme InReach ?
YES!
Simply message us from your DeLorme InReach / Garmin Explorer to:

chris@mwxc.com

and include your:
1. location, course, speed (location should be inserted automatically by InReach, but this does not always happen)
2. wind/sea conditions
3. ask a question, so we can provide the most useful information to aid your decision making

We'll text back your answer/forecast.

Forecasts are $30 each, or $250 for a package of 10, good for 1 year.

You can sign-up by clicking any of the orange "sign-up" links on the website www.mwxc.com then selecting a single phone-in forecast ($30) or a package of (10) for $250. You can use these forecasts by phone or InReach (mix-and-match).

3. SSB Nets schedule / coverage
https://www.mwxc.com/marine_weather_services.php

4. Our Services
We provide high-value-added weather forecasts and routing advice, typically to small sail and power vessels, via SSB Voice Nets, voice telephone, email, SMS text messaging, or any combination.

We cover not only the Caribbean and Bahamas, but US E Coast, Gulf Of Mexico, and the entire Atlantic (Canadian Maritimes, Bermuda, Azores, Canaries, to/from Europe), and in the Pacific we focus on SanDiego-Mexico-C America-Ecuador-Galapagos-Marquesas.

Services:
SSB Nets $199/yr or $99/mo, includes unlimited Daily contact, as often as 6 Days/week. You hail me when you want a forecast and routing advice, there is no daily check-in requirement. This is a custom forecast, just for you, and we can discuss weather and routing as much as you wish. Includes simultaneous interactive Internet Webcasts and recorded forecasts.

Regional Daily Email forecasts $199/yr, $99 for 3 mo, $55/mo, is a regional forecast including travel suggestions and should give you the information you need to make good decisions when moving along the Islands. Is NOT geared for offshore passagemaking (away from the Islands / US Coast), and does NOT include vessel-specific forecasts.

BOTH of the above $299/yr or $129/mo

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Custom (vessel-specific forecasts and routing advice): The SSB Nets above are also Custom forecasts. Custom forecasts via voice telephone, SMS message, or Email are as follows:

Best deal is 10 prepaid forecast credits for $250 may be used as follows (but you may purchase individual forecasts):

phone-in or SMS message ($30/call or 1 forecast credit)
email Detailed 5-day forecast ($65 or 2 forecast credits)
email Detailed 2-day forecast ($35 or 1 forecast credit)
email General 10-day Outlook ($35 or 1 forecast credit)

To purchase any of the above: visit www.mwxc.com and click any orange "sign-up" link, then complete and submit the form. Your order will process in real time and you will receive an automated confirmation email. If not, please call 863-248-2702 to place or troubleshoot your order.

5. Notes
Each time I have contact with a client, I make a NOTE in the database. I can elect to email that NOTE to all email addresses you have selected to receive emails/notes/support.

This works well to email you a brief note if I think you have not copied me well on the SSB Voice Nets, or if you have family back home wanting to know where you are, etc.

If you want me to email NOTEs every time I make one, please let me know (they'd be emailed to all addresses set to receive email/notes/support).

6. Support Request, by email or website
When you email me at support@mwxc.com my system searches the database for client records matching your email address, then tells me when I need to answer your email.

IMPORTANT: the email address in the "From" or "Reply-To" fields of your support request should match an email address in your client record at mwxc.com (questions from existing clients are given priority, and if the system can't match From/Reply-to to your client record, it will assume you are not a client).

The Subject Line of your Support Request MUST contain 3 items (4th is optional):

1. Priority (H, M, L) corresponding to high (you must have an answer) / medium (you would really appreciate an answer) / low (I should answer you only if I have ample time).

2. Date, for example: 05-Dec-2011
Format of date can be:
US standard DD/MM/YY or YYYY (for example 12/5/11)
my preferred format above DD-Month-YY or YYYY (05-Dec-2011)
or even Month DD, YY or YYYY (Dec 5, 2011)

3. Time, in even hours EST/EDT for example: 1700 (1700 hrs EST/EDT)

4. (Optional but suggested) brief text subject, for example: when should I tack

Each item should be separated by a comma. So, the subject line for the above request would look like this:

H, 12/5/11, 1700, when should I tack

NOTE: Weather-related questions should be answered as late as possible, so I can base my answer on the best possible information - while still giving you time to retrieve my answer and incorporate my answer into your plans.

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When you follow the above protocol, here's what happens:
--Your support request appears on my computer, in the proper order so I have the best chance to answer all support requests from existing clients in a timely manner.
--All interactions I have with you, including this support request, are contained in your client record, so I have all your information whenever we interact.
--I provide you with the best possible answer to your question at the optimum time.

Follow-up questions:
If you send a follow-up Support Request, you may remove the old message body (to reduce email size). Within the subject line, you may adjust Priority, Date, Time...but do NOT alter or remove the xxxxx-xxxxx Support Ticket number.

If you have Internet access, you can login to your account at mwxc.com then enter your Support Request from your Client Panel or the Contact page - these are handled in the same manner as email requests.

You can still use the chris@mwxc.com email address for general correspondence, but if you require an answer, I will get you that answer better and faster if you email questions to: support@mwxc.com

When I am on vacation and Ed Bilicki fills in for me, Ed will receive and respond to Support Requests sent to support@mwxc.com (and entered on the website) just as I do.

7. Support Requests - more info
Support Requests emailed to support@mwxc.com are the BEST way for all clients to get useful and timely answers from me on both weather-related and account-related questions.

We've fine-tuned the Support Request feature, as follows:

Requests submitted WITHOUT suggested SUBJECT LINE are now treated as requiring an answer immediately. Previously, they were treated as non-critical requests.

Further discussion...
For best service, please include the following in the SUBJECT LINE of your email to support@mwxc.com :

Priority (H, M, L for high, medium, low), Date-answer-required (any date format you like, but note xx/xx/xxxx will be read as mm/dd/yyyy), Time-answer-required (in hours EST), Subject

Each separated by a COMMA...for instance:

H, 1/14/2012, 1600, when should I cross Anegada Passage

The above request will be treated as critical (High priority), and I'll make every effort to answer it no later than Jan 14, 2012 at 1600 hours EST.

By including the above in your SUBJECT LINE, I will be able to get you the best possible answer at the most-appropriate time.

If you do NOT include the above information in your SUBJECT LINE, then I will have to guess when I should respond.

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When replying to (or re-opening) a Support Request, please enter your reply text BELOW the appropriate line...

OR

DELETE ALL of the message body except for the new text you're sending.

If you simply add your text to the BEGINNING of the email, my system will NOT display the text for me.

I hope the Support Request feature, and other current (and planned) features make Marine Weather Center an even-more-valuable resource when you're Cruising. Thank you for your continuing support!...Chris.

8. Unable to Transmit on SSB? That's OK, I can broadcast your forecast!
If you're unable to transmit on SSB (or I'm consistently unable to hear you when you do), we can still transmit your forecast on the SSB Voice Nets (usually right after the Synopsis), if you do the following:

Email

support@mwxc.com

1. Your email should have the following in the SUBJECT LINE:

H, 1/25/2012, 0600, Transmit forecast on SSB Net

Where H is the priority (high)
1/25/2012 is the date you want me to BEGIN broadcasting the forecast
0600 is the time (important that it's 0600 so I see it 1st thing in the morning)
Transmit forecast on SSB Net tells me what you need

2. in the MESSAGE BODY your:

a. vessel name
b. location
c. Plan (i.e. where you're going, when, and anything else I should know)
d. the SSB Net on which you'd like me to broadcast your forecast

Alternatively, you can ask another vessel to hail me with the above information, or you can call me ahead of time with the above information, at 863-248-2702, and I'll broadcast your forecast as requested.

It's best if you update the above information as frequently as possible, by any means possible.
If I'm broadcasting your forecast over a number of days, please close-the-loop by telling me when I can stop broadcasting your forecast.

9. Why is your forecast different from forecasts from other sources?
I employ a unique methodology, which I call the "worst likely scenario". When preparing your forecast, I consider what might happen, and include in the forecast details for the worst of the plausible scenarios.

This differs from other forecasts, which give you the most-likely scenario.

10. What areas are covered in Regional Daily Email forecasts?
3 Regions available:
E Caribbean (E of 72W)
Bahamas/W Atlantic/US E Coast (as far N as Southern NewEngland in summer)
W Caribbean (W of 72W)

11. What is the "<" symbol in my email forecast
The < symbol indicates a change in conditions over the relevant time period. Read "<" as "becoming".

"240@18<15 this afternoon" means wind will be 240-degrees, starting this afternoon at 18k and becoming 15k.

12. What is "N ROUTE" and "S ROUTE" in my email forecast?
The Bahamas Regional Email forecast offers specific forecast and recommendations on the GulfStream between:

FtPierce / LkWorth - to - MantanillaShola / MemoryRock / WEnd (N ROUTE)

Miami / FtLaud / KyLargo - to - Bimini / S RidingRk / GtBahamaBk (S ROUTE)

13. Regional Daily Email forecast Primer
(Updated Dec 12, 2023)
Marine Weather Center has been serving the Cruising Community for over 17 years, helping people like you not only during offshore passages, but also with economical daily forecasts and advice to make each day more enjoyable year-round.

We deliver forecasts via almost any communications method onboard, including: SSB Radio Voice, voice telephone, email, text message, and interactive internet webcast.

The "Primer" below is specific to our "Regional Daily Email" forecasts, which cover Caribbean, Bahamas, and US E Coast waters. We also specialize in Custom forecasts just about anywhere in the world.

TYPES of Regional Daily Email forecasts:
"EarlyBriefing" for E Caribbean and Bahamas/FL Regions almost every morning, so you have information you need to make decisions about today.
Normal 5-day forecast usually arrives mid-day.
"InterimTropical" is issued for ALL REGIONS when significant Tropical weather is possible.
Other "Interim" emails may be issued for Earthquakes/Tsunamis or significant weather events or emergencies.
"Schedule" emails alert you to changes to Marine Weather Center operations.


Forecasts in several parts:

1.) Recent observational data (may include satellite-derived winds (ASCAT, others), BUOYs, vessel observations). Observations generally start at one end of the forecast area and move logically to the other end, and focus on data which is “curated” by us as representative of conditions you’re likely experiencing now or in the recent past.

2.) Analysis of current satellite / RADAR imagery.

3.) Synopsis of weather features, and their likely influence on your weather for the next 5 days. Format of Synopsis varies as necessary to best describe weather patterns.

4.) Outlook for 5-10 days, or as far into the future as we can make an informed guess.

5.) SUGGEST section (E Caribbean, GulfStream Crossing between S FL and Bahamas, and US E Coast regions): our forecasts are geared to help you make informed weather-based decisions. To further support decision.-making, many of our forecasts include SUGGEST sections where we offer our suggested conclusions regarding travel (which days are best for motoring or sailing in one direction or the other).

6.) Specific forecasts for Precipitation (and wind in squalls) / Winds (excluding squalls) / Swell.

Because one of the most common forecast errors is a slight error in location of predicted weather, we typically divide forecasts by weather-parameter (Precipitation first, then Wind, then Seas), so you see forecasts for adjacent areas above and below your forecast.

More information on sections of the forecasts:

SYNOPSIS:
We always CAPITALIZE weather features, so they stand out in the email. For more information/education, we suggest you start with Chris Parker's book, "Coastal & Offshore Weather, the essential Handbook", available here:

https://www.mwxc.com/order_books.php

But these are terms we use commonly:

LO = low pressure system, a closed area of cyclonic wind, not necessarily perfectly symmetrical, but more round than flat

Parent LO / 2nd-ary LO = a 2nd-ary LO occasionally forms along a FRONT which trails from a Parent LO (an older typically larger LO). Formation of 2nd-ary LO generally causes inclement weather to persist or worsen

HI = high pressure system

RIDGE = flat, weak, high pressure system along an axis

TROF (or trough, including broadly a ColdFRONT, WarmFRONT, StationaryFRONT, OccludedFRONT, InvertedTROF, TropicalWAVE) = an area of lower pressure typically along an axis (pressure not as low as a "LO" pressure system), typically causing nasty weather.

ColdFRONT = TROF (an area of lower pressure along an axis) which marks an advancing cold airmass

WarmFRONT = TROF (an area of lower pressure along an axis) which marks an advancing warm airmass

StationaryFRONT = TROF (an area of lower pressure along an axis) which moves little and separates airmasses

OccludedFRONT = TROF (an area of lower pressure along an axis) which extends from a LO, with cool airmass on both sides of TROF, and warm airmass is displaced away from the LO (this typically signals the LO has peaked (or will soon peak) in strength, due to removal of warm airmass from area near the LO.

InvertedTROF = TROF (an area of lower pressure along an axis) which does not separate airmasses, but does create an area of convergence and lower pressure and typically causes nasty weather, particularly on the side of the TROF with stronger winds.

WAVE = Tropical WAVE, a TROF (an area of lower pressure along an axis) in the Tropics usually moves from E-to-W, and is accompanied by squalls. Most Tropical LOs (Tropical Storms / Hurricanes) develop along a WAVE…and generally do so at the “Apex” of WAVE. Apex is a point usually in N portion of WAVE with greatest pressure drop and vorticity (spin), and winds are usually stronger N of Apex / lighter S of Apex.

2nd-aryFRONT = TROF (an area of lower pressure along an axis) which forms ahead of a ColdFRONT, typically causing strong squalls and a wind shift across the 2nd-aryFRONT. If there is a 2nd-aryFRONT, then the worst weather is usually along and just ahead of the 2nd-aryFRONT, with less-bad weather along the ColdFRONT which passes later.

IMPULSE = Sometimes we have a piece of energy in the atmosphere which is not necessarily a LO (though it may become a LO), typically causing more wind / seas / squalls and wind shifts. Usually forecast models have a hard time with such small, weak areas of energy, so forecast details (and the evolution of the feature) are usually uncertain.
We think it’s important to address such an area of energy, and referring to it as an IMPULSE (of energy) is descriptive.
When we use this term, you should think about it as an area of more windy, squally weather, which might get worse, but the evolution of which is uncertain.


FORECAST:
Detailed forecasts in 3 parts: Precip (and associated wind), Wind (gradient wind and wind-chop), Swell.

Times-of-day convention: whether you can see (daylight), or not (night) is often crucial.
So by "day" we mean when there is enough light to see / "night" is when it's dark.
Further...
Morning = Dawn-Noon
Afternoon = Noon-Sunset
Evening = Sunset-Midnight
Overnight = Midnight-Dawn


PRECIP – We usually discuss coverage of showers and squalls (in order of increasing coverage: stray / isolated / scattered / numerous or widespread), see below for detail. We also discuss character of precip (convergence can be nasty, but not severe, while convective has potential to be severe), and estimate in the precip – sometimes as wind speed “added to gradient wind” (for example if "+10k" then you add 10k to our gradient wind forecast to account for squalls), sometimes as total wind in squalls (for example if "40k", then squalls may pack wind to 40k).

Precipitation coverage: terms like Stray, Isolated, Scattered, Numerous/Widespread are often misunderstood, and there's a big difference between the chance of any given location seeing precipitation (at a single moment of time or over a period of hours or days)....versus any precipitation occurring in a given geographic area (at a specific moment in time or over a period of time).

Stray = mostly dry, but slight chance you may see a shower or squall during specified forecast interval.
Typically 50%+ chance 1 or more showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 5% areal coverage (of the whole forecast area) at any moment, and your chance of seeing one is low (less than 20%) during the forecast interval.

Isolated = mostly dry, but there's a 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.
Typically 80%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 15% areal coverage (of the whole forecast area) at any moment, and 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.

Scattered = there will be showers & squalls around, and you'll almost certainly see some - maybe quite a few.
Typically 95%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and up to 15-50% areal coverage at any moment, and more than 50% chance you see 1-or-more (probably at least a couple) showers/squalls during the forecast interval.

Numerous/Widespread = it'll be very wet, with lots of showers/squalls much of the time.
Typically 100% showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and over 50% areal coverage at times, and close to 100% chance you see 1-or-more (and probably many) showers/squalls during the forecast interval.


WIND – speed & direction:
Direction: Usually in degrees TRUE (for example 060), but when we can't be that specific we'll use cardinal directions (for example ENE). The forecast is NOT so accurate that you should really expect wind exactly 060-degrees. Instead, specificity highlights TRENDs in wind direction: 060-degrees is just about ENE. 070-degrees is also ENE. A change from 060 to 070 suggests a VEERING TREND to the wind direction.

Speed: In knots (nautical miles per hour - 1k = 1.15mph), often in the format 12-15g19k, which should be read as 12 knots to 15 knots, gusting to 19 knots.

L&V = light and variable

Most weather forecasts from other sources give forecasts details for each day. However, weather is fluid and tends to evolve in some sort of a pattern or trend…and we feel it’s wrong to describe something like weather in discrete, arbitrary intervals (like days).

Instead, when there are trends in conditions, our forecasts describe those trends over the time period during which the trend unfolds. For instance, some forecasts might say NE@12 Sun1, ENE@15 Mon2 and E@18 Tue3. But, if this is a gradual TREND, which unfolds at a steady progression, then it’s far more useful to say today starts at 040@10, and wind gradually, steadily increases & veers to 100@20 by the end of Tue3. And the way we write this is 040@10<100@20 Sun1-Tue3.

The “<” symbol tells you we’re describing a TREND in conditions over the time we specify at the END of the phrase, and the “<” symbol should be read as the word BECOMING.

So a more complex phrase 060@10-13g16<080@16-20g25 Wed16-Thu17 night is read:

Wind 060-degrees True at 10 knots to 13 knots, gusting to 16 knots, BECOMING 080-degrees True at 16 knots to 20 knots, gusting to 25 knots from Wed16 through Thu17 night.

During some intervals, there’s no trend – just steady conditions, so in that case we would not note a trend.

Another unconventional part of our forecast: We describe the weather FIRST, and THEN tell you what timeframe those conditions will be in effect. Whether it’s squall activity, gradient wind, or seas, we generally explain what the weather will be like…THEN we tell you what time period will experience that sort of weather. This may seem counter-intuitive, but it allows you to easily identify good or bad weather conditions, and then see during what interval of time those conditions are predicted to occur. Our format also facilitates describing trends. (In some extreme weather events the formatting will change, but it will be obvious, and we’ll note the non-standard formatting in the forecast).

All of the above actually helps you make better decisions based on the weather forecast, since you can see how & when the weather is evolving/trending (for better or worse).

REMEMBER TO CONSIDER WIND IN SQUALLS! Our “Wind” forecast is generally for wind in the absence of significant squalls. ALWAYS refer to the “PRECIP” forecast for wind in squalls!


SEAS – There are 3 types of wave forecasts:
"Wind-chop": waves attributable to local wind. These waves are typically steep, but as long as they are not large, they're not problematic.

"Swell", "Primary wave" (and Secondary and Tertiary) waves. Computer model forecasts generally focus on the Primary wave, specifically the "Primary Significant Wave" (the mathematical average of the 33% of largest waves in the largest wave train). If this is wind-driven, then interval of this wave is about 1 second per foot of wave height (6'/6sec). If this is swell (driven by wind somewhere else) then the wave interval will be longer than 1 second per foot of wave height.

"Seas": the aggregate "Significant Wave", (mathematical average of the 33% of largest waves), combining wind-chop and all other wave trains. NOAA's NWS predicts "Seas".

At Marine Weather Center, we examine seas in 2 ways:
For wind-chop:
In the E Caribbean and US E Coast forecasts, we specify wind-chop embedded within the WIND forecast (following a "/" after the wind forecast), so you'll see something like this:
090@15/4'
predicting 4' wind-chop. These are generally wind-driven seas, and include seas resulting from locally-higher wind in any predicted squalls.

In other geographic areas, you can estimate wind-chop yourself based on this rule-of-thumb: Wind blowing for more than an hour-or-so even over modest fetch, as long as depth does not restrict wave height, will be (or wind-driven waves will be so steep they will feel like):

10k = 2′
13k = 3′
15k = 4′
18k = 5′
20k = 6′
25k = 8-9′
30k = 10-12′

Where water depth limits wave height, you can think of the following descriptors: calm, light chop, moderate chop, choppy. We typically avoid detailing waves where water depth limits wave height, because wave height and steepness vary dramatically as depth changes. Instead, we detail wave height as if water were deep, and let you adjust downward for your specific water depth.

Under "SWELL", we predict height, periodicity, and direction of the Primary (largest) wave train, as well as any meaningful Secondary and Tertiary wave trains.

Our forecasts assume waves are not limited by water depth or fetch (the distance wind blows over water between you and any upwind landmass or upwind very shallow water). In areas where fetch and depth are limited (parts of Bahamas, Virgin Islands, along any Coast where wind is blowing from land, and areas in the lee of islands in the Caribbean) fetch (and often water depth) limit wave height - the extent to which wave height is limited depends on your precise location, so we always assume unrestricted depth and fetch. Therefore, in E Caribbean and Bahamas our seas forecast is for E of the islands.

Stated differently:
We want to predict unfiltered seas (not filtered by the islands)...we want to do this because the amount of filtering from islands varies significantly depending on the user's exact location (which changes minute-to-minute if you're underway), and we can't know that, so unfiltered seas are best.

Additionally, particularly in E Caribbean, seas (and wind) between Islands in the Windwards/Leewards are typically higher (due to funneling / compression) than over open waters away from Islands...and the Islands also bend wind & sea directions locally. Because the extent to which wave height is larger and wave direction is different depends on your precise location, you must adjust for this.

Again, our forecasts for wind & seas assumes you're in exposed areas, and away from the local effects imparted by Islands, shallow waters, etc.

Along US E Coast and Florida, seas immediately following wind forecast (090@15/4') are wind-chop, but if we include interval and direction of seas, then it's swell.

Acceleration: What you really care about is the ACCELERATION of motion of your vessel due to seas. By acceleration, we mean any change in motion versus what you'd have with flat calm seas.

In general, seas with an interval much greater than 1-second-per-foot of height are swells. 6' seas with 6-sec interval is a wind-chop. 6' seas with 8-sec interval are short-interval swells. 6' seas with a 12-sec interval are long-interval swells. Swells are less-steep, and, therefore, impart less acceleration on the vessel for a given height.

Acceleration (and implications for boat handling) also vary considerably on your vessel's length, beam, weight (and weight distribution), and hull shape. The acceleration imparted by 6' wind-chop with 6-sec interval will be very different on a heavy 30' sailboat versus a light 30' sailboat, a 50' sailboat or a 30' powerboat.

Also, apparent wave interval (and acceleration) change depending on your direction of motion relative to seas: apparent wave interval shortens (usually increasing acceleration) when heading into waves / lengthens (usually decreasing acceleration) when heading with waves.


HOW TO INTERPRET OUR WIND-CHOP and SWELL FORECASTS:
For wave HEIGHT: we suggest you start with wind-chop forecast, then add 50% of our swell forecast.

Here's an example: in Leewards we can get unfiltered swell by looking just E of Guadeloupe-Barbuda, and just N&E of Barbuda-StMartin. For that area, let's say

Wind is 090@18-20, so wind-chop forecast is 6' (6-seconds interval is implied because it's wind-chop).
Primary wave (Swell) forecast is 8-10'/12secNE (that's 8-10 feet with 12-seconds interval from the NE).

Based on our rule-of-thumb assumption for phasing of wave trains we add wind-wave of 6' + 50% of swell (4-5') = 10-11' perceived wave height.

The added benefit of knowing the wave components (wind-chop and swell) is you can further assess comfort by considering swell interval and direction.

The 12-seconds interval of the swell is about 2x the 6-seconds interval of wind-chop, so you will see a swell wave about the same time as every-other wind-chop wave.

For wave DIRECTION: Swell direction is NE, which is 45-degrees from the 090T wind direction. So the overall seastate described above is a 6' wave from the E, followed 6 seconds later by a 10-11' wave from the NE & E (triangular wave peak), then 6 seconds later a 6' wave from E, followed 6 seconds later by another 10-11' wave from NE & E (triangular wave peak).

That's 10-11' of motion 5x a minute (every 12 seconds), and in a jerky, confused motion. Sounds very uncomfortable! Without describing the wind-chop and swell individually, we would not be able to appreciate the actual overall seastate and its influence on our vessel.

Why do we not add the full height of both wave trains (6' + 8-10' = 14-16')? Because wave height is from trough-to-crest (not from mean sealevel to crest), and because wind-chop and swell are of different intervals, both trough and crest will not phase in the same wave. Adding 50% of swell to wind-chop is a reasonable approximation.

Example B: wind 090@10-13, wind-chop 2-3', swell 6'/12secE. Wind-chop is 2-3' every 2-3 seconds, which is benign for all but very small fast dinghies because it's so small. There will be a larger wave (2-3' + 50% of 6' (3'), so that's 2-3' + 3' = 5-6') every 12 seconds. But this is only 5-6' of motion 5x per minute, and the motion is very regular because wind-chop and swell are from same direction. This sea would be very comfortable on most boats.

Decision making based on our seastate forecasts:
Start by considering wind-chop and any swell independently. Are both acceptable by themselves?

If so, then consider how wind-chop and swell phase. Start with wind-chop and add 50% of swell height. Still acceptable?

If so, then consider whether wind-chop and swell are from similar directions? If so, then wave motion will be in a consistent direction / if not, then wave motion will be confused.

Currents / GulfStream: When wind blows against any strong current (tidal or geostrophic (non-tidal, such as GulfStream)), sea height is commonly 50% larger than without current, and wave interval is similar or even steeper than without current. So in GulfStream or in tidal current of 3-4k a 6'/6sec wind-chop may really be 9'/5sec, which imparts close to 2x the acceleration on the vessel. In addition, wave direction often becomes somewhat random, so the acceleration is confused.

GEOGRAPHY:
ALL FORECASTS: For locations near the boundary between areas, you should average conditions in the 2 areas. For instance, if you're transiting waters between StLucia-Guadeloupe, and we give a forecast for SE Caribbean and NE Caribbean, then you'll average the 2 forecasts.
When conditions vary significantly within an area, we'll break that area into smaller pieces.

E CARIBBEAN:
SE Caribbean = Martinique-Trinidad
Windwards = Martinique-Grenada
NE Caribbean = Dominica-Leewards-VI-PR (always S Coast of PR unless specified)
Leewards = Guadeloupe-StMartin/Anguilla
Virgins = British, US, and Spanish Virgins and the E Coast of PR from Fajardo-PlamasDelMar
MonaPsg = route to/from N Coast of the DR via HourglassShoal area toward Mayaguez/PuertoReal
DR = N Coast of DR unless specified
Venezuela = offshore, N of 12N
ABCs = Aruba-Bonaire-Curacao

*.*

BAHAMAS/FL:
CROSSING – waters between Florida and Bahamas (and along Coast of FL)
N ROUTE = MemoryRock-MantanillaShoal-WestEnd…to LakeWorth-FtPierce
S ROUTE = GreatIsaac-Bimini-SouthRidingRock…to FtLauderdale-Miami-KeyLargo

NW Bahamas = all areas N of Eleuthera and N of NewProvidence and N of Andros
C Bahamas = NewProvidence, Andros, Eluthera, Exumas, CatIsland, N part of LongIsland, Conception, Rum, SanSalvador, sometimes Jumentos
SE Bahamas = S part of LongIsland, Crooked, Acklins, and all Islands S&E to Provo Turks & Caicos, sometimes including Jumentos
T&C = T&C and waters between T&C and LuperonDR

Occasionally we’ll reference other areas:
E-most islands of the Bahamas = Mayaguana, Samama, Rum, SanSal, Conception, Cat, Eleuthera, Abaco
SW Bahamas = Andros-CaySalBank and parts of GreatBahamaBank
FLStraits = waters S of FLKeys toward Cuba
N Bahamas = Abaco-GrandBahama-LittleBahamaBank

OTHER AREAS section varies by season:
NFL = FL/GA border to PonceInlet
CFL = S of PonceInlet to FtPierce
CROSSING - N Route, includes FL Coast from FtPierce to N of FtLauderdale
CROSSING - S Route, includes FL Coast from FtLauderdale thru KyLargo
KyW = FL Keys from Islamorada to/from DryTortugas
SW FL = Marathon or KyW to/from Naples-PortCharlotte area (seasonal, not in summer)

*.*

US E COAST, outside the ICW (in the Ocean), seasonal, assuming N-to-S travel (inshore of the GulfStream) from September1-March15 / S-to-N travel (including the GulfStream) from March15-August31:

Maine and YarmouthNS to CpCod, including GulfOfMaine (typically late May-late September)
S of CpCodCanal / NewportRI and SandyHook to CpMay and Norfolk (typically late April-early November)
Norfolk-Hatteras-BeaufortNC (typically April1-November30)
BeaufortNC along entire Coast to FL/GA border (year-round)

*.*

W CARIBBEAN:
For vessels transiting ColombianCoast…
Very briefly…when Trade winds are in place, semi-permanent LO over Colombia causes large compression zone with strong wind. Though this zone moves, it’s typically 20-120 mi from shore, but often penetrates to the Coast from the SantaMarta area to 11N/76W. Our Colombia forecast focuses on the strongest wind you are likely to encounter. Computer models typically fail to mix catabatic / downslope winds to the surface, when in actuality these winds do penetrate to the surface. We know this, and we compensate for it, so our forecasts should be accurate, and are often much higher than computer models predict. If you are plying these waters, you may be well served to purchase a detailed "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

* *
Panama: E Panama includes SanBlas/GunaYala & adjacent areas to Linton. C Panama includes the area about 40mi on either side of the Canal. W Panama includes BocasDelToro & adjacent areas.
* *
P-S-A stands for Providencia-SanAndreas-AlbuquerqueCays, and adjacent reefs/islands (generally 12N-14N from 80W-82W).
* *
Honduras forecasts generally focus on the greater BayIslands area (Guanaja, Roatan, Utila) between 86W-87W. Conditions can vary greatly Gauanaja, but this area is typically transited briefly, and when plying offshore waters of W Caribbean we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).
* *
“SW Corner of NW Caribbean” typically includes from Placentia S-ward thru Guatemala's RioDulce, and extreme W Honduras. In this area the seabreeze / landbreeze patterns of Belize and Honduras dominate, often resulting in light wind except for a brief late afternoon-evening NE-ENE seabreeze. However nighttime into morning squalls/T-strms are also common, due in part to the convergence of nighttime landbreezes (daytime seabreezes are divergent and therefore typically suppress squalls).
* *
During periods of enhanced E-SE wind a large zone of strong catabatic wind blows (late afternoons into overnights) from the Honduran mountains thru waters within 100mi of the BayIslands, and often propagate into parts of Belize and S Mexico. The exact location of these winds shifts, and can result in dramatic differences in wind between Utila and Guanaja.
* *
ColdFRONTs typically lack much energy when they move thru NW (and SW) Caribbean, and veering S-W wind is unusual (it’s more-common Mexico’sYucatan). Severe weather accompanying a FRONT is due not only to tight gradient, but also to convergence caused by landmasses (often with some instability/convection causing the most-severe squalls along FrontalTROF). It is not uncommon for stronger ColdFRONTs to propagate N wind (and strong squalls) into SW Caribbean, with wind funneling along C America and adjacent waters, all the way to W Panama.
* *
Mexico forecast focuses on the IslaMujeres-Cozumel area, N of 20N. For S of 20N, average the Mexico & Belize forecasts in all respects, unless specified otherwise.
* *
Other areas:
Jamaica focuses on waters off PortAntonio (NE Jamaica) and Kingston (SE Jamaica) to approximate weather for vessels approaching / departing via WindwardPsg, S Coast of Hispanola, P-S-A, Panama, and Colombia. However, vessels transiting offshore waters of Caribbean should purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

Caymans: when there is a significant nighttime landbreeze coming off Cuba, it typically takes a few hours to propagate to Caymans, resulting in a diurnal wind pattern in Caymans which peaks early mornings.

Cuba, we focus our Regional Email forecasts on 2 areas:
CayoLargo archipelago, including Juventud and Cienfuegos
Jardines (area N of CaboCruz thru and including TrinidaDeCuba)
We are glad to cover all other areas in Cuba with "Custom" forecasts (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

S Coast of Haiti & DomRep / offshore passage routes are not frequented by Cruising vessels (except briefly in-transit), so we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

If this does not answer all your questions about interpreting Regional Email forecasts, please let us know.

14. Regional Daily Email forecast Primer
Marine Weather Center has been serving the Cruising Community for over 17 years, helping people like you not only during offshore passages, but also with economical daily forecasts and advice to make each day more enjoyable year-round.

We deliver forecasts via almost any communications method onboard, including: SSB Radio Voice, voice telephone, email, text message, and interactive internet webcast.

The "Primer" below is specific to our "Regional Daily Email" forecasts, which cover Caribbean, Bahamas, and US E Coast waters. We also specialize in Custom forecasts just about anywhere in the world.

TYPES of Regional Daily Email forecasts:
"EarlyBriefing" for E Caribbean and Bahamas/FL Regions almost every morning, so you have information you need to make decisions about today.
Normal 5-day forecast usually arrives mid-day.
"InterimTropical" is issued for ALL REGIONS when significant Tropical weather is possible.
Other "Interim" emails may be issued for Earthquakes/Tsunamis or significant weather events or emergencies.
"Schedule" emails alert you to changes to Marine Weather Center operations.


Forecasts in several parts:

1.) Recent observational data (may include satellite-derived winds (ASCAT, others), BUOYs, vessel observations). Observations generally start at one end of the forecast area and move logically to the other end, and focus on data which is “curated” by us as representative of conditions you’re likely experiencing now or in the recent past.

2.) Analysis of current satellite / RADAR imagery.

3.) Synopsis of weather features, and their likely influence on your weather for the next 5 days. Format of Synopsis varies as necessary to best describe weather patterns.

4.) Outlook for 5-10 days, or as far into the future as we can make an informed guess.

5.) SUGGEST section (E Caribbean, GulfStream Crossing between S FL and Bahamas, and US E Coast regions): our forecasts are geared to help you make informed weather-based decisions. To further support decision.-making, many of our forecasts include SUGGEST sections where we offer our suggested conclusions regarding travel (which days are best for motoring or sailing in one direction or the other).

6.) Specific forecasts for Precipitation (and wind in squalls) / Winds (excluding squalls) / Swell.

Because one of the most common forecast errors is a slight error in location of predicted weather, we typically divide forecasts by weather-parameter (Precipitation first, then Wind, then Seas), so you see forecasts for adjacent areas above and below your forecast.

More information on sections of the forecasts:

SYNOPSIS:
We always CAPITALIZE weather features, so they stand out in the email. For more information/education, we suggest you start with Chris Parker's book, "Coastal & Offshore Weather, the essential Handbook", available here:

https://www.mwxc.com/order_books.php

LO = low pressure system

2nd-ary LO = LO which forms along FRONT trailing from a LO, generally causing inclement weather to persist or worsen

HI = high pressure system

RIDGE = flat, weak, high pressure system along an axis

TROF (and ColdFRONT / WarmFRONT) = flat, weak area lower pressure along an axis, typically causing nasty weather

2nd-ary FRONT = often a LO supports more than one ColdFRONT. 2nd-ary FRONT(s) reinforce the established flow and often bring more veering of wind direction

WAVE = Tropical WAVE, a TROF (an area of lower pressure along an axis) in the Tropics usually moves from E-to-W, and is accompanied by squalls. Most Tropical LOs (Tropical Storms / Hurricanes) develop along a WAVE…and generally do so at the “Apex” of WAVE. Apex is a point usually in N portion of WAVE with greatest pressure drop and vorticity (spin), and winds are usually stronger N of Apex / lighter S of Apex.

IMPULSE = Sometimes we have a piece of energy in the atmosphere which is not necessarily a LO (though it may become one). Maybe it’s an area along a TROF (or a ColdFRONT or a WarmFRONT) where there’s more wind / seas / squalls. Usually forecast models have a hard time with such small, weak areas of energy, so forecast details (and the evolution of the feature) are usually uncertain.
We think it’s important to address such an area of energy, and referring to it as an IMPULSE (of energy) is descriptive.
When we use this term, you should think about it as an area of more windy, squally weather, which might get worse, but the evolution of which is uncertain.


FORECAST:
Detailed forecasts in 3 parts: Precip (and associated wind), Wind (gradient wind and wind-chop), Swell.

Times-of-day convention: whether you can see (daylight), or not (night) is often crucial.
So by "day" we mean when there is enough light to see / "night" is when it's dark.
Further...
Morning = Dawn-Noon
Afternoon = Noon-Sunset
Evening = Sunset-Midnight
Overnight = Midnight-Dawn


PRECIP – We usually discuss coverage of showers and squalls (in order of increasing coverage: stray isolated / scattered / numerous or widespread), see below for detail. We also discuss character of precip (convergence can be nasty, but not severe, while convective has potential to be severe), and estimate in the precip – sometimes as wind speed “added to gradient wind” (for example if "+10k" then you add 10k to our gradient wind forecast to account for squalls), sometimes as total wind in squalls (for example if "40k", then squalls may pack wind to 40k).

Precipitation coverage: terms like Stray, Isolated, Scattered, Numerous/Widespread are often misunderstood, and there's a big difference between the chance of any given location seeing precipitation (at a single moment of time or over a period of hours or days)....versus any precipitation occurring in a given geographic area (at a specific moment in time or over a period of time).

Stray = mostly dry, but slight chance you may see a shower or squall during specified forecast interval.
Typically 50%+ chance 1 or more showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 5% areal coverage (of the whole forecast area) at any moment, and your chance of seeing one is low (less than 20%) during the forecast interval.

Isolated = mostly dry, but there's a 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.
Typically 80%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 15% areal coverage (of the whole forecast area) at any moment, and 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.

Scattered = there will be showers & squalls around, and you'll almost certainly see some - maybe quite a few.
Typically 95%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and up to 15-50% areal coverage at any moment, and more than 50% chance you see 1-or-more (probably at least a couple) showers/squalls during the forecast interval.

Numerous/Widespread = it'll be very wet, with lots of showers/squalls much of the time.
Typically 100% showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and over 50% areal coverage at times, and close to 100% chance you see 1-or-more (and probably many) showers/squalls during the forecast interval.


WIND – speed & direction:
Direction: Usually in degrees TRUE (for example 060), but when we can't be that specific we'll use cardinal directions (for example ENE). The forecast is NOT so accurate that you should really expect wind exactly 060-degrees. Instead, specificity highlights TRENDs in wind direction: 060-degrees is just about ENE. 070-degrees is also ENE. A change from 060 to 070 suggests a VEERING TREND to the wind direction.

Speed: In knots (nautical miles per hour - 1k = 1.15mph), often in the format 12-15g19k, which should be read as 12 knots to 15 knots, gusting to 19 knots.

L&V = light and variable

Most weather forecasts from other sources give forecasts details for each day. However, weather is fluid and tends to evolve in some sort of a pattern or trend…and we feel it’s wrong to describe something like weather in discrete, arbitrary intervals (like days).

Instead, when there are trends in conditions, our forecasts describe those trends over the time period during which the trend unfolds. For instance, some forecasts might say NE@12 Sun1, ENE@15 Mon2 and E@18 Tue3. But, if this is a gradual TREND, which unfolds at a steady progression, then it’s far more useful to say today starts at 040@10, and wind gradually, steadily increases & veers to 100@20 by the end of Tue3. And the way we write this is 040@10<100@20 Sun1-Tue3.

The “<” symbol tells you we’re describing a TREND in conditions over the time we specify at the END of the phrase, and the “<” symbol should be read as the word BECOMING.

So a more complex phrase 060@10-13g16<080@16-20g25 Wed16-Thu17 night is read:

Wind 060-degrees True at 10 knots to 13 knots, gusting to 16 knots, BECOMING 080-degrees True at 16 knots to 20 knots, gusting to 25 knots from Wed16 through Thu17 night.

During some intervals, there’s no trend – just steady conditions, so in that case we would not note a trend.

Another unconventional part of our forecast: We describe the weather FIRST, and THEN tell you what timeframe those conditions will be in effect. Whether it’s squall activity, gradient wind, or seas, we generally explain what the weather will be like…THEN we tell you what time period will experience that sort of weather. This may seem counter-intuitive, but it allows you to easily identify good or bad weather conditions, and then see during what interval of time those conditions are predicted to occur. Our format also facilitates describing trends. (In some extreme weather events the formatting will change, but it will be obvious, and we’ll note the non-standard formatting in the forecast).

All of the above actually helps you make better decisions based on the weather forecast, since you can see how & when the weather is evolving/trending (for better or worse).

REMEMBER TO CONSIDER WIND IN SQUALLS! Our “Wind” forecast is generally for wind in the absence of significant squalls. ALWAYS refer to the “PRECIP” forecast for wind in squalls!


SEAS – There are 3 types of wave forecasts:
"Wind-chop": waves attributable to local wind. These waves are typically steep, but as long as they are not large, they're not problematic.

"Swell", "Primary wave" (and Secondary and Tertiary) waves. Computer model forecasts generally focus on the Primary wave, specifically the "Primary Significant Wave" (the mathematical average of the 33% of largest waves in the largest wave train). If this is wind-driven, then interval of this wave is about 1 second per foot of wave height (6'/6sec). If this is swell (driven by wind somewhere else) then the wave interval will be longer than 1 second per foot of wave height.

"Seas": the aggregate "Significant Wave", (mathematical average of the 33% of largest waves), combining wind-chop and all other wave trains. NOAA's NWS predicts "Seas".

At Marine Weather Center, we examine seas in 2 ways:
For wind-chop:
In the E Caribbean and US E Coast forecasts, we specify wind-chop embedded within the WIND forecast (following a "/" after the wind forecast), so you'll see something like this:
090@15/4'
predicting 4' wind-chop. These are generally wind-driven seas, and include seas resulting from locally-higher wind in any predicted squalls.

In other geographic areas, you can estimate wind-chop yourself based on this rule-of-thumb: Wind blowing for more than an hour-or-so even over modest fetch, as long as depth does not restrict wave height, will be (or wind-driven waves will be so steep they will feel like):

10k = 2′
13k = 3′
15k = 4′
18k = 5′
20k = 6′
25k = 8-9′
30k = 10-12′

Where water depth limits wave height, you can think of the following descriptors: calm, light chop, moderate chop, choppy. We typically avoid detailing waves where water depth limits wave height, because wave height and steepness vary dramatically as depth changes. Instead, we detail wave height as if water were deep, and let you adjust downward for your specific water depth.

Under "SWELL", we predict height, periodicity, and direction of the Primary (largest) wave train, as well as any meaningful Secondary and Tertiary wave trains.

Our forecasts assume waves are not limited by water depth or fetch (the distance wind blows over water between you and any upwind landmass or upwind very shallow water). In areas where fetch and depth are limited (parts of Bahamas, Virgin Islands, along any Coast where wind is blowing from land, and areas in the lee of islands in the Caribbean) fetch (and often water depth) limit wave height - the extent to which wave height is limited depends on your precise location, so we always assume unrestricted depth and fetch. Therefore, in E Caribbean and Bahamas our seas forecast is for E of the islands.

Stated differently:
We want to predict unfiltered seas (not filtered by the islands)...we want to do this because the amount of filtering from islands varies significantly depending on the user's exact location (which changes minute-to-minute if you're underway), and we can't know that, so unfiltered seas are best.

Additionally, particularly in E Caribbean, seas (and wind) between Islands in the Windwards/Leewards are typically higher (due to funneling / compression) than over open waters away from Islands...and the Islands also bend wind & sea directions locally. Because the extent to which wave height is larger and wave direction is different depends on your precise location, you must adjust for this.

Again, our forecasts for wind & seas assumes you're in exposed areas, and away from the local effects imparted by Islands, shallow waters, etc.

Along US E Coast and Florida, seas immediately following wind forecast (090@15/4') are wind-chop, but if we include interval and direction of seas, then it's swell.

Acceleration: What you really care about is the ACCELERATION of motion of your vessel due to seas. By acceleration, we mean any change in motion versus what you'd have with flat calm seas.

In general, seas with an interval much greater than 1-second-per-foot of height are swells. 6' seas with 6-sec interval is a wind-chop. 6' seas with 8-sec interval are short-interval swells. 6' seas with a 12-sec interval are long-interval swells. Swells are less-steep, and, therefore, impart less acceleration on the vessel for a given height.

Acceleration (and implications for boat handling) also vary considerably on your vessel's length, beam, weight (and weight distribution), and hull shape. The acceleration imparted by 6' wind-chop with 6-sec interval will be very different on a heavy 30' sailboat versus a light 30' sailboat, a 50' sailboat or a 30' powerboat.

Also, apparent wave interval (and acceleration) change depending on your direction of motion relative to seas: apparent wave interval shortens (usually increasing acceleration) when heading into waves / lengthens (usually decreasing acceleration) when heading with waves.


HOW TO INTERPRET OUR WIND-CHOP and SWELL FORECASTS:
For wave HEIGHT: we suggest you start with wind-chop forecast, then add 50% of our swell forecast.

Here's an example: in Leewards we can get unfiltered swell by looking just E of Guadeloupe-Barbuda, and just N&E of Barbuda-StMartin. For that area, let's say

Wind is 090@18-20, so wind-chop forecast is 6' (6-seconds interval is implied because it's wind-chop).
Primary wave (Swell) forecast is 8-10'/12secNE (that's 8-10 seconds feet with 12-seconds interval from the NE).

Based on our rule-of-thumb assumption for phasing of wave trains we add wind-wave of 6' + 50% of swell (4-5') = 10-11' perceived wave height.

The added benefit of knowing the wave components (wind-chop and swell) is you can further assess comfort by considering swell interval and direction.

The 12-seconds interval of the swell is about 2x the 6-seconds interval of wind-chop, so you will see a swell wave about the same time as every-other wind-chop wave.

For wave DIRECTION: Swell direction is NE, which is 45-degrees from the 090T wind direction. So the overall seastate described above is a 6' wave from the E, followed 6 seconds later by a 10-11' wave from the NE & E (triangular wave peak), then 6 seconds later a 6' wave from E, followed 6 seconds later by another 10-11' wave from NE & E (triangular wave peak).

That's 10-11' of motion 5x a minute (every 12 seconds), and in a jerky, confused motion. Sounds very uncomfortable! Without describing the wind-chop and swell individually, we would not be able to appreciate the actual overall seastate and its influence on our vessel.

Why do we not add the full height of both wave trains (6' + 8-10' = 14-16')? Because wave height is from trough-to-crest (not from mean sealevel to crest), and because wind-chop and swell are of different intervals, both trough and crest will not phase in the same wave. Adding 50% of swell to wind-chop is a reasonable approximation.

Example B: wind 090@10-13, wind-chop 2-3', swell 6'/12secE. Wind-chop is 2-3' every 2-3 seconds, which is benign for all but very small fast dinghies because it's so small. There will be a larger wave (2-3' + 50% of 6' (3'), so that's 2-3' + 3' = 5-6') every 12 seconds. But this is only 5-6' of motion 5x per minute, and the motion is very regular because wind-chop and swell are from same direction. This sea would be very comfortable on most boats.

Decision making based on our seastate forecasts:
Start by considering wind-chop and any swell independently. Are both acceptable by themselves?

If so, then consider how wind-chop and swell phase. Start with wind-chop and add 50% of swell height. Still acceptable?

If so, then consider whether wind-chop and swell are from similar directions? If so, then wave motion will be in a consistent direction / if not, then wave motion will be confused.

Currents / GulfStream: When wind blows against any strong current (tidal or geostrophic (non-tidal, such as GulfStream)), sea height is commonly 50% larger than without current, and wave interval is similar or even steeper than without current. So in GulfStream or in tidal current of 3-4k a 6'/6sec wind-chop may really be 9'/5sec, which imparts close to 2x the acceleration on the vessel. In addition, wave direction often becomes somewhat random, so the acceleration is confused.

GEOGRAPHY:
ALL FORECASTS: For locations near the boundary between areas, you should average conditions in the 2 areas. For instance, if you're transiting waters between StLucia-Guadeloupe, and we give a forecast for SE Caribbean and NE Caribbean, then you'll average the 2 forecasts.
When conditions vary significantly within an area, we'll break that area into smaller pieces.

E CARIBBEAN:
SE Caribbean = Martinique-Trinidad
Windwards = Martinique-Grenada
NE Caribbean = Dominica-Leewards-VI-PR (always S Coast of PR unless specified)
Leewards = Guadeloupe-StMartin/Anguilla
Virgins = British, US, and Spanish Virgins and the E Coast of PR from Fajardo-PlamasDelMar
MonaPsg = route to/from N Coast of the DR via HourglassShoal area toward Mayaguez/PuertoReal
DR = N Coast of DR unless specified
Venezuela = offshore, N of 12N
ABCs = Aruba-Bonaire-Curacao

*.*

BAHAMAS/FL:
CROSSING – waters between Florida and Bahamas
N ROUTE = MemoryRock-MantanillaShoal-WestEnd…to LakeWorth-FtPierce
S ROUTE = GreatIsaac-Bimini-SouthRidingRock…to FtLauderdale-Miami-KeyLargo

NW Bahamas = all areas N of Eleuthera and N of NewProvidence and N of Andros
C Bahamas = NewProvidence, Andros, Eluthera, Exumas, CatIsland, N part of LongIsland, Conception, Rum, SanSalvador, sometimes Jumentos
SE Bahamas = S part of LongIsland, Crooked, Acklins, and all Islands S&E to Provo Turks & Caicos, sometimes including Jumentos
T&C = T&C and waters between T&C and LuperonDR

Occasionally we’ll reference other areas:
E-most islands of the Bahamas = Mayaguana, Samama, Rum, SanSal, Conception, Cat, Eleuthera, Abaco
SW Bahamas = Andros-CaySalBank and parts of GreatBahamaBank
FLStraits = waters S of FLKeys toward Cuba
N Bahamas = Abaco-GrandBahama-LittleBahamaBank

OTHER AREAS section varies by season:
NFL = FL/GA border to PonceInlet
CFL = S of PonceInlet to FtPierce
CROSSING - N Route, includes FL Coast from FtPierce to N of FtLauderdale
CROSSING - S Route, includes FL Coast from FtLauderdale thru KyLargo
KyW = FL Keys from Islamorada to/from DryTortugas
SW FL = Marathon or KyW to/from Naples-PortCharlotte area (seasonal, not in summer)

*.*

US E COAST, outside the ICW (in the Ocean), seasonal, assuming N-to-S travel (inshore of the GulfStream) from September1-March15 / S-to-N travel (including the GulfStream) from March15-August31:

Maine and YarmouthNS to CpCod, including GulfOfMaine (typically late May-late September)
S of CpCodCanal / NewportRI and SandyHook to CpMay and Norfolk (typically late April-early November)
Norfolk-Hatteras-BeaufortNC (typically April1-November30)
BeaufortNC along entire Coast to FL/GA border (year-round)

*.*

W CARIBBEAN:
For vessels transiting ColombianCoast…
Very briefly…when Trade winds are in place, semi-permanent LO over Colombia causes large compression zone with strong wind. Though this zone moves, it’s typically 20-120 mi from shore, but often penetrates to the Coast from the SantaMarta area to 11N/76W. Our Colombia forecast focuses on the strongest wind you are likely to encounter. Computer models typically fail to mix catabatic / downslope winds to the surface, when in actuality these winds do penetrate to the surface. We know this, and we compensate for it, so our forecasts should be accurate, and are often much higher than computer models predict. If you are plying these waters, you may be well served to purchase a detailed "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

* *
Panama: E Panama includes SanBlas/GunaYala & adjacent areas to Linton. C Panama includes the area about 40mi on either side of the Canal. W Panama includes BocasDelToro & adjacent areas.
* *
P-S-A stands for Providencia-SanAndreas-AlbuquerqueCays, and adjacent reefs/islands (generally 12N-14N from 80W-82W).
* *
Honduras forecasts generally focus on the greater BayIslands area (Guanaja, Roatan, Utila) between 86W-87W. Conditions can vary greatly Gauanaja, but this area is typically transited briefly, and when plying offshore waters of W Caribbean we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).
* *
“SW Corner of NW Caribbean” typically includes from Placentia S-ward thru Guatemala's RioDulce, and extreme W Honduras. In this area the seabreeze / landbreeze patterns of Belize and Honduras dominate, often resulting in light wind except for a brief late afternoon-evening NE-ENE seabreeze. However nighttime into morning squalls/T-strms are also common, due in part to the convergence of nighttime landbreezes (daytime seabreezes are divergent and therefore typically suppress squalls).
* *
During periods of enhanced E-SE wind a large zone of strong catabatic wind blows (late afternoons into overnights) from the Honduran mountains thru waters within 100mi of the BayIslands, and often propagate into parts of Belize and S Mexico. The exact location of these winds shifts, and can result in dramatic differences in wind between Utila and Guanaja.
* *
ColdFRONTs typically lack much energy when they move thru NW (and SW) Caribbean, and veering S-W wind is unusual (it’s more-common Mexico’sYucatan). Severe weather accompanying a FRONT is due not only to tight gradient, but also to convergence caused by landmasses (often with some instability/convection causing the most-severe squalls along FrontalTROF). It is not uncommon for stronger ColdFRONTs to propagate N wind (and strong squalls) into SW Caribbean, with wind funneling along C America and adjacent waters, all the way to W Panama.
* *
Mexico forecast focuses on the IslaMujeres-Cozumel area, N of 20N. For S of 20N, average the Mexico & Belize forecasts in all respects, unless specified otherwise.
* *
Other areas:
Jamaica focuses on waters off PortAntonio (NE Jamaica) and Kingston (SE Jamaica) to approximate weather for vessels approaching / departing via WindwardPsg, S Coast of Hispanola, P-S-A, Panama, and Colombia. However, vessels transiting offshore waters of Caribbean should purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

Caymans: when there is a significant nighttime landbreeze coming off Cuba, it typically takes a few hours to propagate to Caymans, resulting in a diurnal wind pattern in Caymans which peaks early mornings.

Cuba, we focus our Regional Email forecasts on 2 areas:
CayoLargo archipelago, including Juventud and Cienfuegos
Jardines (area N of CaboCruz thru and including TrinidaDeCuba)
We are glad to cover all other areas in Cuba with "Custom" forecasts (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

S Coast of Haiti & DomRep / offshore passage routes are not frequented by Cruising vessels (except briefly in-transit), so we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

If this does not answer all your questions about interpreting Regional Email forecasts, please let us know.

15. Regional Daily Email forecast Primer
Marine Weather Center has been serving the Cruising Community for over 17 years, helping people like you not only during offshore passages, but also with economical daily forecasts and advice to make each day more enjoyable year-round.

We deliver forecasts via almost any communications method onboard, including: SSB Radio Voice, voice telephone, email, text message, and interactive internet webcast.

The "Primer" below is specific to our "Regional Daily Email" forecasts, which cover Caribbean, Bahamas, and US E Coast waters. We also specialize in Custom forecasts just about anywhere in the world.

TYPES of Regional Daily Email forecasts:
"EarlyBriefing" for E Caribbean and Bahamas/FL Regions almost every morning, so you have information you need to make decisions about today.
Normal 5-day forecast usually arrives mid-day.
"InterimTropical" is issued for ALL REGIONS when significant Tropical weather is possible.
Other "Interim" emails may be issued for Earthquakes/Tsunamis or significant weather events or emergencies.
"Schedule" emails alert you to changes to Marine Weather Center operations.


Forecasts in several parts:

1.) Recent observational data (may include satellite-derived winds (ASCAT, others), BUOYs, vessel observations). Observations generally start at one end of the forecast area and move logically to the other end, and focus on data which is “curated” by us as representative of conditions you’re likely experiencing now or in the recent past.

2.) Analysis of current satellite / RADAR imagery.

3.) Synopsis of weather features, and their likely influence on your weather for the next 5 days. Format of Synopsis varies as necessary to best describe weather patterns.

4.) Outlook for 5-10 days, or as far into the future as we can make an informed guess.

5.) SUGGEST section (E Caribbean, GulfStream Crossing between S FL and Bahamas, and US E Coast regions): our forecasts are geared to help you make informed weather-based decisions. To further support decision.-making, many of our forecasts include SUGGEST sections where we offer our suggested conclusions regarding travel (which days are best for motoring or sailing in one direction or the other).

6.) Specific forecasts for Precipitation (and wind in squalls) / Winds (excluding squalls) / Swell.

Because one of the most common forecast errors is a slight error in location of predicted weather, we typically divide forecasts by weather-parameter (Precipitation first, then Wind, then Seas), so you see forecasts for adjacent areas above and below your forecast.

More information on sections of the forecasts:

SYNOPSIS:
We always CAPITALIZE weather features, so they stand out in the email. For more information/education, we suggest you start with Chris Parker's book, "Coastal & Offshore Weather, the essential Handbook", available here:

https://www.mwxc.com/order_books.php

LO = low pressure system

2nd-ary LO = LO which forms along FRONT trailing from a LO, generally causing inclement weather to persist or worsen

HI = high pressure system

RIDGE = flat, weak, high pressure system along an axis

TROF (and ColdFRONT / WarmFRONT) = flat, weak area lower pressure along an axis, typically causing nasty weather

2nd-ary FRONT = often a LO supports more than one ColdFRONT. 2nd-ary FRONT(s) reinforce the established flow and often bring more veering of wind direction

WAVE = Tropical WAVE, a TROF (an area of lower pressure along an axis) in the Tropics usually moves from E-to-W, and is accompanied by squalls. Most Tropical LOs (Tropical Storms / Hurricanes) develop along a WAVE…and generally do so at the “Apex” of WAVE. Apex is a point usually in N portion of WAVE with greatest pressure drop and vorticity (spin), and winds are usually stronger N of Apex / lighter S of Apex.

IMPULSE = Sometimes we have a piece of energy in the atmosphere which is not necessarily a LO (though it may become one). Maybe it’s an area along a TROF (or a ColdFRONT or a WarmFRONT) where there’s more wind / seas / squalls. Usually forecast models have a hard time with such small, weak areas of energy, so forecast details (and the evolution of the feature) are usually uncertain.
We think it’s important to address such an area of energy, and referring to it as an IMPULSE (of energy) is descriptive.
When we use this term, you should think about it as an area of more windy, squally weather, which might get worse, but the evolution of which is uncertain.


FORECAST:
Detailed forecasts in 3 parts: Precip (and associated wind), Wind (gradient wind and wind-chop), Swell.

Times-of-day convention: whether you can see (daylight), or not (night) is often crucial.
So by "day" we mean when there is enough light to see / "night" is when it's dark.
Further...
Morning = Dawn-Noon
Afternoon = Noon-Sunset
Evening = Sunset-Midnight
Overnight = Midnight-Dawn


PRECIP – We usually discuss coverage of showers and squalls (in order of increasing coverage: stray / isolated / scattered / numerous or widespread), see below for detail. We also discuss character of precip (convergence can be nasty, but not severe, while convective has potential to be severe), and estimate in the precip – sometimes as wind speed “added to gradient wind” (for example if "+10k" then you add 10k to our gradient wind forecast to account for squalls), sometimes as total wind in squalls (for example if "40k", then squalls may pack wind to 40k).

Precipitation coverage: terms like Stray, Isolated, Scattered, Numerous/Widespread are often misunderstood, and there's a big difference between the chance of any given location seeing precipitation (at a single moment of time or over a period of hours or days)....versus any precipitation occurring in a given geographic area (at a specific moment in time or over a period of time).

Stray = mostly dry, but slight chance you may see a shower or squall during specified forecast interval.
Typically 50%+ chance 1 or more showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 5% areal coverage (of the whole forecast area) at any moment, and your chance of seeing one is low (less than 20%) during the forecast interval.

Isolated = mostly dry, but there's a 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.
Typically 80%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, but less than 15% areal coverage (of the whole forecast area) at any moment, and 20%-50% chance you see 1 or more showers/squalls during specified forecast interval.

Scattered = there will be showers & squalls around, and you'll almost certainly see some - maybe quite a few.
Typically 95%+ certain some showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and up to 15-50% areal coverage at any moment, and more than 50% chance you see 1-or-more (probably at least a couple) showers/squalls during the forecast interval.

Numerous/Widespread = it'll be very wet, with lots of showers/squalls much of the time.
Typically 100% showers/squalls in the area (not necessarily your location) at some time during the forecast interval, and over 50% areal coverage at times, and close to 100% chance you see 1-or-more (and probably many) showers/squalls during the forecast interval.


WIND – speed & direction:
Direction: Usually in degrees TRUE (for example 060), but when we can't be that specific we'll use cardinal directions (for example ENE). The forecast is NOT so accurate that you should really expect wind exactly 060-degrees. Instead, specificity highlights TRENDs in wind direction: 060-degrees is just about ENE. 070-degrees is also ENE. A change from 060 to 070 suggests a VEERING TREND to the wind direction.

Speed: In knots (nautical miles per hour - 1k = 1.15mph), often in the format 12-15g19k, which should be read as 12 knots to 15 knots, gusting to 19 knots.

L&V = light and variable

Most weather forecasts from other sources give forecasts details for each day. However, weather is fluid and tends to evolve in some sort of a pattern or trend…and we feel it’s wrong to describe something like weather in discrete, arbitrary intervals (like days).

Instead, when there are trends in conditions, our forecasts describe those trends over the time period during which the trend unfolds. For instance, some forecasts might say NE@12 Sun1, ENE@15 Mon2 and E@18 Tue3. But, if this is a gradual TREND, which unfolds at a steady progression, then it’s far more useful to say today starts at 040@10, and wind gradually, steadily increases & veers to 100@20 by the end of Tue3. And the way we write this is 040@10<100@20 Sun1-Tue3.

The “<” symbol tells you we’re describing a TREND in conditions over the time we specify at the END of the phrase, and the “<” symbol should be read as the word BECOMING.

So a more complex phrase 060@10-13g16<080@16-20g25 Wed16-Thu17 night is read:

Wind 060-degrees True at 10 knots to 13 knots, gusting to 16 knots, BECOMING 080-degrees True at 16 knots to 20 knots, gusting to 25 knots from Wed16 through Thu17 night.

During some intervals, there’s no trend – just steady conditions, so in that case we would not note a trend.

Another unconventional part of our forecast: We describe the weather FIRST, and THEN tell you what timeframe those conditions will be in effect. Whether it’s squall activity, gradient wind, or seas, we generally explain what the weather will be like…THEN we tell you what time period will experience that sort of weather. This may seem counter-intuitive, but it allows you to easily identify good or bad weather conditions, and then see during what interval of time those conditions are predicted to occur. Our format also facilitates describing trends. (In some extreme weather events the formatting will change, but it will be obvious, and we’ll note the non-standard formatting in the forecast).

All of the above actually helps you make better decisions based on the weather forecast, since you can see how & when the weather is evolving/trending (for better or worse).

REMEMBER TO CONSIDER WIND IN SQUALLS! Our “Wind” forecast is generally for wind in the absence of significant squalls. ALWAYS refer to the “PRECIP” forecast for wind in squalls!


SEAS – There are 3 types of wave forecasts:
"Wind-chop": waves attributable to local wind. These waves are typically steep, but as long as they are not large, they're not problematic.

"Swell", "Primary wave" (and Secondary and Tertiary) waves. Computer model forecasts generally focus on the Primary wave, specifically the "Primary Significant Wave" (the mathematical average of the 33% of largest waves in the largest wave train). If this is wind-driven, then interval of this wave is about 1 second per foot of wave height (6'/6sec). If this is swell (driven by wind somewhere else) then the wave interval will be longer than 1 second per foot of wave height.

"Seas": the aggregate "Significant Wave", (mathematical average of the 33% of largest waves), combining wind-chop and all other wave trains. NOAA's NWS predicts "Seas".

At Marine Weather Center, we examine seas in 2 ways:
For wind-chop:
In the E Caribbean and US E Coast forecasts, we specify wind-chop embedded within the WIND forecast (following a "/" after the wind forecast), so you'll see something like this:
090@15/4'
predicting 4' wind-chop. These are generally wind-driven seas, and include seas resulting from locally-higher wind in any predicted squalls.

In other geographic areas, you can estimate wind-chop yourself based on this rule-of-thumb: Wind blowing for more than an hour-or-so even over modest fetch, as long as depth does not restrict wave height, will be (or wind-driven waves will be so steep they will feel like):

10k = 2′
13k = 3′
15k = 4′
18k = 5′
20k = 6′
25k = 8-9′
30k = 10-12′

Where water depth limits wave height, you can think of the following descriptors: calm, light chop, moderate chop, choppy. We typically avoid detailing waves where water depth limits wave height, because wave height and steepness vary dramatically as depth changes. Instead, we detail wave height as if water were deep, and let you adjust downward for your specific water depth.

Under "SWELL", we predict height, periodicity, and direction of the Primary (largest) wave train, as well as any meaningful Secondary and Tertiary wave trains.

Our forecasts assume waves are not limited by water depth or fetch (the distance wind blows over water between you and any upwind landmass or upwind very shallow water). In areas where fetch and depth are limited (parts of Bahamas, Virgin Islands, along any Coast where wind is blowing from land, and areas in the lee of islands in the Caribbean) fetch (and often water depth) limit wave height - the extent to which wave height is limited depends on your precise location, so we always assume unrestricted depth and fetch. Therefore, in E Caribbean and Bahamas our seas forecast is for E of the islands.

Stated differently:
We want to predict unfiltered seas (not filtered by the islands)...we want to do this because the amount of filtering from islands varies significantly depending on the user's exact location (which changes minute-to-minute if you're underway), and we can't know that, so unfiltered seas are best.

Additionally, particularly in E Caribbean, seas (and wind) between Islands in the Windwards/Leewards are typically higher (due to funneling / compression) than over open waters away from Islands...and the Islands also bend wind & sea directions locally. Because the extent to which wave height is larger and wave direction is different depends on your precise location, you must adjust for this.

Again, our forecasts for wind & seas assumes you're in exposed areas, and away from the local effects imparted by Islands, shallow waters, etc.

Along US E Coast and Florida, seas immediately following wind forecast (090@15/4') are wind-chop, but if we include interval and direction of seas, then it's swell.

Acceleration: What you really care about is the ACCELERATION of motion of your vessel due to seas. By acceleration, we mean any change in motion versus what you'd have with flat calm seas.

In general, seas with an interval much greater than 1-second-per-foot of height are swells. 6' seas with 6-sec interval is a wind-chop. 6' seas with 8-sec interval are short-interval swells. 6' seas with a 12-sec interval are long-interval swells. Swells are less-steep, and, therefore, impart less acceleration on the vessel for a given height.

Acceleration (and implications for boat handling) also vary considerably on your vessel's length, beam, weight (and weight distribution), and hull shape. The acceleration imparted by 6' wind-chop with 6-sec interval will be very different on a heavy 30' sailboat versus a light 30' sailboat, a 50' sailboat or a 30' powerboat.

Also, apparent wave interval (and acceleration) change depending on your direction of motion relative to seas: apparent wave interval shortens (usually increasing acceleration) when heading into waves / lengthens (usually decreasing acceleration) when heading with waves.


HOW TO INTERPRET OUR WIND-CHOP and SWELL FORECASTS:
For wave HEIGHT: we suggest you start with wind-chop forecast, then add 50% of our swell forecast.

Here's an example: in Leewards we can get unfiltered swell by looking just E of Guadeloupe-Barbuda, and just N&E of Barbuda-StMartin. For that area, let's say

Wind is 090@18-20, so wind-chop forecast is 6' (6-seconds interval is implied because it's wind-chop).
Primary wave (Swell) forecast is 8-10'/12secNE (that's 8-10 seconds feet with 12-seconds interval from the NE).

Based on our rule-of-thumb assumption for phasing of wave trains we add wind-wave of 6' + 50% of swell (4-5') = 10-11' perceived wave height.

The added benefit of knowing the wave components (wind-chop and swell) is you can further assess comfort by considering swell interval and direction.

The 12-seconds interval of the swell is about 2x the 6-seconds interval of wind-chop, so you will see a swell wave about the same time as every-other wind-chop wave.

For wave DIRECTION: Swell direction is NE, which is 45-degrees from the 090T wind direction. So the overall seastate described above is a 6' wave from the E, followed 6 seconds later by a 10-11' wave from the NE & E (triangular wave peak), then 6 seconds later a 6' wave from E, followed 6 seconds later by another 10-11' wave from NE & E (triangular wave peak).

That's 10-11' of motion 5x a minute (every 12 seconds), and in a jerky, confused motion. Sounds very uncomfortable! Without describing the wind-chop and swell individually, we would not be able to appreciate the actual overall seastate and its influence on our vessel.

Why do we not add the full height of both wave trains (6' + 8-10' = 14-16')? Because wave height is from trough-to-crest (not from mean sealevel to crest), and because wind-chop and swell are of different intervals, both trough and crest will not phase in the same wave. Adding 50% of swell to wind-chop is a reasonable approximation.

Example B: wind 090@10-13, wind-chop 2-3', swell 6'/12secE. Wind-chop is 2-3' every 2-3 seconds, which is benign for all but very small fast dinghies because it's so small. There will be a larger wave (2-3' + 50% of 6' (3'), so that's 2-3' + 3' = 5-6') every 12 seconds. But this is only 5-6' of motion 5x per minute, and the motion is very regular because wind-chop and swell are from same direction. This sea would be very comfortable on most boats.

Decision making based on our seastate forecasts:
Start by considering wind-chop and any swell independently. Are both acceptable by themselves?

If so, then consider how wind-chop and swell phase. Start with wind-chop and add 50% of swell height. Still acceptable?

If so, then consider whether wind-chop and swell are from similar directions? If so, then wave motion will be in a consistent direction / if not, then wave motion will be confused.

Currents / GulfStream: When wind blows against any strong current (tidal or geostrophic (non-tidal, such as GulfStream)), sea height is commonly 50% larger than without current, and wave interval is similar or even steeper than without current. So in GulfStream or in tidal current of 3-4k a 6'/6sec wind-chop may really be 9'/5sec, which imparts close to 2x the acceleration on the vessel. In addition, wave direction often becomes somewhat random, so the acceleration is confused.

GEOGRAPHY:
ALL FORECASTS: For locations near the boundary between areas, you should average conditions in the 2 areas. For instance, if you're transiting waters between StLucia-Guadeloupe, and we give a forecast for SE Caribbean and NE Caribbean, then you'll average the 2 forecasts.
When conditions vary significantly within an area, we'll break that area into smaller pieces.

E CARIBBEAN:
SE Caribbean = Martinique-Trinidad
Windwards = Martinique-Grenada
NE Caribbean = Dominica-Leewards-VI-PR (always S Coast of PR unless specified)
Leewards = Guadeloupe-StMartin/Anguilla
Virgins = British, US, and Spanish Virgins and the E Coast of PR from Fajardo-PlamasDelMar
MonaPsg = route to/from N Coast of the DR via HourglassShoal area toward Mayaguez/PuertoReal
DR = N Coast of DR unless specified
Venezuela = offshore, N of 12N
ABCs = Aruba-Bonaire-Curacao

*.*

BAHAMAS/FL:
CROSSING – waters between Florida and Bahamas
N ROUTE = MemoryRock-MantanillaShoal-WestEnd…to LakeWorth-FtPierce
S ROUTE = GreatIsaac-Bimini-SouthRidingRock…to FtLauderdale-Miami-KeyLargo

NW Bahamas = all areas N of Eleuthera and N of NewProvidence and N of Andros
C Bahamas = NewProvidence, Andros, Eluthera, Exumas, CatIsland, N part of LongIsland, Conception, Rum, SanSalvador, sometimes Jumentos
SE Bahamas = S part of LongIsland, Crooked, Acklins, and all Islands S&E to Provo Turks & Caicos, sometimes including Jumentos
T&C = T&C and waters between T&C and LuperonDR

Occasionally we’ll reference other areas:
E-most islands of the Bahamas = Mayaguana, Samama, Rum, SanSal, Conception, Cat, Eleuthera, Abaco
SW Bahamas = Andros-CaySalBank and parts of GreatBahamaBank
FLStraits = waters S of FLKeys toward Cuba
N Bahamas = Abaco-GrandBahama-LittleBahamaBank

OTHER AREAS section varies by season:
NFL = FL/GA border to PonceInlet
CFL = S of PonceInlet to FtPierce
CROSSING - N Route, includes FL Coast from FtPierce to N of FtLauderdale
CROSSING - S Route, includes FL Coast from FtLauderdale thru KyLargo
KyW = FL Keys from Islamorada to/from DryTortugas
SW FL = Marathon or KyW to/from Naples-PortCharlotte area (seasonal, not in summer)

*.*

US E COAST, outside the ICW (in the Ocean), seasonal, assuming N-to-S travel (inshore of the GulfStream) from September1-March15 / S-to-N travel (including the GulfStream) from March15-August31:

Maine and YarmouthNS to CpCod, including GulfOfMaine (typically late May-late September)
S of CpCodCanal / NewportRI and SandyHook to CpMay and Norfolk (typically late April-early November)
Norfolk-Hatteras-BeaufortNC (typically April1-November30)
BeaufortNC along entire Coast to FL/GA border (year-round)

*.*

W CARIBBEAN:
For vessels transiting ColombianCoast…
Very briefly…when Trade winds are in place, semi-permanent LO over Colombia causes large compression zone with strong wind. Though this zone moves, it’s typically 20-120 mi from shore, but often penetrates to the Coast from the SantaMarta area to 11N/76W. Our Colombia forecast focuses on the strongest wind you are likely to encounter. Computer models typically fail to mix catabatic / downslope winds to the surface, when in actuality these winds do penetrate to the surface. We know this, and we compensate for it, so our forecasts should be accurate, and are often much higher than computer models predict. If you are plying these waters, you may be well served to purchase a detailed "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

* *
Panama: E Panama includes SanBlas/GunaYala & adjacent areas to Linton. C Panama includes the area about 40mi on either side of the Canal. W Panama includes BocasDelToro & adjacent areas.
* *
P-S-A stands for Providencia-SanAndreas-AlbuquerqueCays, and adjacent reefs/islands (generally 12N-14N from 80W-82W).
* *
Honduras forecasts generally focus on the greater BayIslands area (Guanaja, Roatan, Utila) between 86W-87W. Conditions can vary greatly Gauanaja, but this area is typically transited briefly, and when plying offshore waters of W Caribbean we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).
* *
“SW Corner of NW Caribbean” typically includes from Placentia S-ward thru Guatemala's RioDulce, and extreme W Honduras. In this area the seabreeze / landbreeze patterns of Belize and Honduras dominate, often resulting in light wind except for a brief late afternoon-evening NE-ENE seabreeze. However nighttime into morning squalls/T-strms are also common, due in part to the convergence of nighttime landbreezes (daytime seabreezes are divergent and therefore typically suppress squalls).
* *
During periods of enhanced E-SE wind a large zone of strong catabatic wind blows (late afternoons into overnights) from the Honduran mountains thru waters within 100mi of the BayIslands, and often propagate into parts of Belize and S Mexico. The exact location of these winds shifts, and can result in dramatic differences in wind between Utila and Guanaja.
* *
ColdFRONTs typically lack much energy when they move thru NW (and SW) Caribbean, and veering S-W wind is unusual (it’s more-common Mexico’sYucatan). Severe weather accompanying a FRONT is due not only to tight gradient, but also to convergence caused by landmasses (often with some instability/convection causing the most-severe squalls along FrontalTROF). It is not uncommon for stronger ColdFRONTs to propagate N wind (and strong squalls) into SW Caribbean, with wind funneling along C America and adjacent waters, all the way to W Panama.
* *
Mexico forecast focuses on the IslaMujeres-Cozumel area, N of 20N. For S of 20N, average the Mexico & Belize forecasts in all respects, unless specified otherwise.
* *
Other areas:
Jamaica focuses on waters off PortAntonio (NE Jamaica) and Kingston (SE Jamaica) to approximate weather for vessels approaching / departing via WindwardPsg, S Coast of Hispanola, P-S-A, Panama, and Colombia. However, vessels transiting offshore waters of Caribbean should purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

Caymans: when there is a significant nighttime landbreeze coming off Cuba, it typically takes a few hours to propagate to Caymans, resulting in a diurnal wind pattern in Caymans which peaks early mornings.

Cuba, we focus our Regional Email forecasts on 2 areas:
CayoLargo archipelago, including Juventud and Cienfuegos
Jardines (area N of CaboCruz thru and including TrinidaDeCuba)
We are glad to cover all other areas in Cuba with "Custom" forecasts (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

S Coast of Haiti & DomRep / offshore passage routes are not frequented by Cruising vessels (except briefly in-transit), so we suggest you purchase a "Custom" forecast (or a subscription to Webcasts/SSB Voice Nets, where we can discuss weather one-on-one).

If this does not answer all your questions about interpreting Regional Email forecasts, please let us know.

16. I have stopped receiving email forecasts, even though my subscription is current
Email Service Providers attempt to limit SPAM by "blacklisting" servers which send a large percentage of emails which are undeliverable or whose recipients mark then as SPAM.

In an effort to make sure our server is not flagged as a Spamming server, we have a "gatekeeper" which prevents our server from sending email to an address which has previously flagged us as SPAM or has had any sort of email delivery problem (like an expired email account or a misspelled email address).

Solution: please email us, and we'll eliminate your email address from our email suppression system.

17. What methods of payment are accepted?
We accept Visa, Mastercard, Discover, and American Express.

If you strongly prefer to pay by check, please contact: chris@mwxc.com

18. I'm not getting email forecasts I signed-up for.
First, check settings on your account/subscription:
1. For all emails, make sure you have the appropriate address(es) selected to receive forecasts.
2. For Regional Daily Forecasts, do you have a current Subscription?
3. For Regional Daily Forecasts, make sure you have 1-or-more "Regions" selected.

If the above are correct and you're still not getting forecasts, then contact Chris Parker:
863-248-2702
chris@mwxc.com
support@mwxc.com

The following is a description of the likely culprit:

We have a "smart" email system (maybe too smart).

In this world overflowing with SPAM, the last thing a legitimate email sender wants is to be "blacklisted" as a spammer, or to have our SPAM SCORE so high that legitimate emails end-up getting automatically filtered into the recipient's SPAM folder.

Our system tries to prevent this in 2 ways:

1. If you ever (even once by mistake) flag an email from Marine Weather Center as SPAM, and your email service provider sends that information to our server, our server will never send you another email.

2. If an email to you ever bounces (is undeliverable) for any reason (you let an email address lapse, etc), our server will never send you another email.

In the above cases, even if our List Server follows your instructions to generate the email forecast, our email "Policeman" prevents our server from sending your forecast.

If you contact me, I can make our "Email Policeman" FORGET there was ever a problem delivering mail to you...and it should then allow email forecasts to pass to you.

19. Is your website secure?
Yes, mwxc.com website has a SSL 3.0 security certificate (notice the "https" on the sign-up form).

We follow credit card industry "best practices", and every 3 months we re-verify "PCI-compliance".

Here's what happens when you make a payment on www.mwxc.com:

Our server checks the order for errors, and, if none, submits your information for payment authorization. The very second your payment is approved, your subscription is active (or your scheduled product is on the schedule).

We do not store your complete credit card number on our website, and indeed our website never records your complete credit card number at all.

Instead, when you submit an order, we pass your credit card info to our payment processor (ePN), and they pass it to your bank, and if credit card info matches what your bank has on file, then the transaction is approved.

Along with the approval, your bank then passes back to ePN (and they pass to us) a unique Transaction ID, which we can use (along with the last-4 digits of yuor card number + expiration date, which we DO store securely) to make any future purchases you approve.

If we are hacked, and the hacker obtains the Transaction ID, then any charges they make to your card fund our bank account (not the hacker's bank account), so the Transaction IDs are useless to a hacker.

20. How can I receive my forecast?
Via ANY communications capabilities beyond VHF radio. Basically, if you can communicate with the outside world beyond VHF range, you can receive our forecasts. Methods include: email, phone, fax, and SSB radio voice nets.

21. Can you email me a copy of an old forecast / forecast for a previous day?
Actually, you can retrieve ANY email forecast which was sent to you since April 15, 2011.
Login to your account, then click "View/Search All Regional Forecasts"

We are working on allowing access to email forecasts since April 15, 2011, for Regions which were not sent to you, and for any periods for which you were not a subscriber...if you need one of these, please email chris@mwxc.com

22. Custom (vessel-specific) forecasts by Email
Many clients use our Custom (vessel-specific) email forecasts.

Forecast (except general 10-day Outlook) generally includes:
1. summary of current weather and sea conditions
2. SYNOPSIS of major weather features and their expected influence on you
3. analysis of and optimized routing based on Sea Surface Currents
4. Detailed forecast of wind speed and direction; estimate of wind in squalls; and height, direction and interval of both swells and wind-driven seas - all every 12-hours out to 2-days or 5-days, with more-granularity to time intervals near significant weather events.
5. suggested TACTICS you may wish to employ to optimize your trip, given the expected conditions at each 12-hour interval.
6. suggest when you may want to request your next forecast Update

You can order the initial forecast on the website www.mwxc.com or by phone or email.

Forecasts can be charged to your credit card as you request them, or you can purchase a package of forecasts in advance, as follows:

--Detailed 5-day forecast and routing advice with 10-day Outlook $65
--Detailed 2-day forecast and routing advice $35
--General 10-day Outlook $35 (useful for ensuring vessels on long passages are maintaining the best route for the overall weather pattern, while the vessel handles their own day-to-day forecasting)
--Package of (10) Custom forecasts for $250 (each $35 forecast or $30 phone-in forecast will count as one (1) forecast / each $65 forecast counts as two (2) of your ten (10) forecasts).

TO REQUEST SUBSEQUENT FORECASTS:

email me in the morning with the following, and I'll email your forecast later in the day:

1. your Location, course and speed
2. weather and sea conditions
3. your PLAN (and anything else I should know when preparing your forecast)
4. type of forecast you're requesting:
--5-day forecast $65
--2-day forecast $35
--general 10-day Outlook $35

Schedule your 1st forecast for 1-2 days before your earliest intended departure.

I'll contact you within 24hrs before sending the forecast to confirm favorable weather for your departure. If conditions are not favorable for departure, I'll continue monitoring weather (and communicating with you every couple days) until there's a suitable departure opportunity. So the 1st forecast includes a Departure Window recommendation.

23. I'm on a long passage. How much will Custom (vessel-specific) email forecasts cost?
Cost varies depending on how self-reliant you are, and how bad or changeable weather conditions are.

Some self-reliant folks cross the Atlantic with just 3 or 4 "general 10-day Outlooks" and one or two "2-day forecasts" when there's a significant upcoming weather event. Forecasts for their entire Atlantic crossing can be $100-or-so.

Other folks prefer more input from me on their forecasting and routing. Most folks request about $100 of forecasts each week on extended offshore passages.

24. I want a Custom forecast by email. How do you decide when to send the forecast?
When you order your initial Custom email forecast, please schedule it for 1-3 days before your 1st possible departure date. You will want to schedule the forecast for the day on which you will begin to make final departure preparations/decisions.

On the day you schedule, I'll look at your request, and assess the weather situation, and read any NOTES you've made on the order. Then I will contact you (by email or phone) to confirm when you'll be ready to depart, and that the weather looks good.

If you are not ready to depart, or the weather is not good, then we'll re-schedule an assessment for 1-2 days later...and we'll keep doing this until you're ready to go and the weather is good.

The forecast is a single forecast (for 2 days or 5 days, whichever you choose). To order additional forecasts:
If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

When you want another email forecast, please email me the following in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

25. What if weather is no good?
On the day before your forecast is due (2 days prior to your earliest departure date), if conditions do not look acceptable, I'll contact you by phone or email to re-schedule your forecast.

I'll continue doing this as many times as necessary to identify a departure opportunity you deem acceptable.

Of course, once we agree I should send you the detailed forecast, and I send the forecast, if you later decide not to go, the order will still be considered to be completed.

26. How do I order another forecast?
CUSTOM FORECASTS:
-- Custom forecast for you and your vessel / itinerary, working one-on-one with a meteorologist
-- Departure planning (we monitor weather for as long as it takes to find suitable departure opportunity, suggest departure timing)
-- Synopsis of weather features
-- Sea surface currents / GulfStream
-- Detailed forecast including gradient wind, estimate coverage of and wind in squalls, wind-driven wave, swell, fog, ice
-- Routing advice (Waypoints, typically customized for comfort/safety, speed optimization a secondary objective)
--Tactical advice (suggestions on when to tack, how close to the wind to sail, how to respond to evolving weather)
-- 365 days/yr
-- Almost anywhere on Earth (not Arctic / Antarctic / Somalia-GulfOfAden-RedSea-SuezCanal)
-- Via email, voice telephone, text (cell phone, sat phone, InReach/Explorer, Zoleo, BIVY Stick, SpotX), and webcast.

If you want a forecast by phone ($35 or 1 forecast credit), call 863-248-2702, after 10am AST/EDT

We typically schedule initial weather assessment for 3 days prior to the earliest you expect to be ready to depart, so you can coordinate pre-departure activities. Once we agree on departure timing, we email detailed forecast and routing advice the day before departure (or the morning of departure if you're departing later in the day).

Departure Planning: If weather is not conducive for departure near your intended departure date, and pre-departure weather assessments and communications with you continue for more than a few days to find an acceptable departure opportunity, then your forecast needs Departure Planning ($25 or 1 Credit in addition to the detailed forecast).

To schedule a pre-departure forecast, please email to: chris@mwxc.com the following:

1. where you intend to depart from (and your present position, if different)
2. when you expect to be ready to depart
3. intended destination (final destination as well as at least your 1st planned stop, or if nonstop let us know that too).
4. anything else we should know about his Journey.

Each forecast will include our suggestion when to request your next forecast (this assessment is based on forecast uncertainty, the potential for high-impact weather, and timing of Decision Points along your journey, where you will need to make a weather-based decision.

We can format forecasts for sending via text messaging, but we can be more verbose / nuanced via regular email. Text message (including satellite phones / Garmin Explorer / InReach / Zoleo / BIVY Stick / Spot-X): send to chris@mwxc.com (or, if you must send to a phone number, use 941-915-7608). Be sure include details #1-#3 below, and ask specific questions, so we can be sure to provide the best answer in the constraints of SMS messaging.

If we expect you to need an additional forecast while underway, then our forecast should include our suggestion on when to request your next forecast. This is based on our confidence in the forecast, and the timing of any significant weather events, or weather-related decisions you will need to make.

When you want another email forecast, please send us the following in the early morning (preferably between 0600 utc to 1200 utc), and we will email your forecast during the day (we can also schedule these in advance):

#1: your location / course / speed (and sail configuration if applicable)
#2: weather / sea conditions
#3: your PLAN, and anything we should know when creating your forecast, as well as any specific questions we should answer
#4: REQUEST that I email you one of the following forecasts:

Credits can be used for email / text forecasts:
--5-day forecast with 10-day Outlook ($70 or 2 credits)
--5-day forecast with 10-day Outlook + Departure planning ($95 or 3 credits)
--2-day forecast ($40 or 1 credit)
--2-day forecast + Departure planning ($65 or 2 credits)
--General 10-day Outlook ($40 or 1 credit)
--phone-in forecast ($35 or 1 credit)
--video conference with recording ($70 or 2 credits)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $299. Forecast credits expire 1 year from date of purchase).

TO PURCHASE:
If you do NOT have an account, please visit https://www.mwxc.com/signup.php
then complete and submit the form, or call 863-248-2702 anytime after 10am AST/EDT.

If you DO have an account, login to your account (if you do not remember your credentials follow the prompts to "Retrieve your login information"). Once logged in, either Renew your previous service or click the "SIGN-UP NOW FOR NEW SERVICES" link.

*.*

To request a pre-departure email forecast, please email us. We need to know the following at a minimum:
1. Present location
2. Location you'll depart from (if different)
3. Destination - typically the destinations on your next 2 or 3 legs, as we want to weigh our recommendations for a specific leg against how those recommendations may impact future legs.

For instance, if you're going from NewportRI to CapeMay, then we'll recommend the best day to do that. But if we know you then want to go to Norfolk the next day, we may recommend doing the 1st leg a day earlier even if not ideal, so that you can complete the 2nd leg before weather deteriorates.

4. Date/Time you intend to depart

5. Anything else we should know. For example, do you have family members onboard who need particularly mild weather? Do you need a weather assessment several days before departure so you can make travel plans? Do you have a hard deadline for arriving at some destination?

27. Will you monitor the weather and contact us if things change?
No. Some folks might object to a forecaster contacting them (and billing them) for a forecast when they don't need it. I have no shortage of work, and no desire to charge you for anything you don't feel you need.

INSTEAD, each forecast includes my recommendation on when you should contact me for another forecast. For instance, if there is a little ColdFRONT expected on Friday, and a small uncertainty in its track, I might suggest you email me for a forecast Thursday, so you have a day to make small alterations in course...if it's a major system and/or a major uncertainty and you might require more advance notice to make a bigger course change, then I might suggest you email me Wednesday or even Tuesday.

Although not every forecast verifies with 100% precision, each forecast includes a discussion of uncertainties / forecast confidence, and possibility for severe weather. Almost all forecasts which which require frequent revision do so because of uncertainties or potential for severe weather which we discussed previously.

You may also notice your weather conditions are beginning to deviate from the previous forecast, and you'll decide you want an earlier update.

28. I'm on passage, and want a forecast emailed to me each day, can you do that?
I'll be glad to email you a forecast each day.

However, I ask that you email me each morning you want a forecast with your:

1. location, course, speed
2. weather/sea conditions
3. PLAN, and anything else I should know when creating your forecast
4. REQUEST that I email you one of the following:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

WHY DO I NOT JUST EMAIL FORECAST AUTOMATICALLY?:

My strong opinion is you need a weather forecast/routing advice in order to answer questions / make strategic decisions.

My forecast is NOT the "most likely scenario" you may get from other sources. Rather, it is the worst-plausible scenario for your situation, and I include routing and strategic advice/suggestions which you can use to optimize your passage.

Although I'm pretty good at guessing and pro-actively providing the answers to questions/decisions you may need to make, my forecasts will be FAR MORE USEFUL if they specifically address your:

a. overall PLAN
b. strategic discussions you've been having onboard
c. and if I take into account any vessel/crew issues you may be having

The only way I know this information, and can provide the best value-added forecast/routing advice is for you to email this information before I begin preparing your forecast.

29. How often should I request a new Custom Email forecast?
See the above answer for clues it's time to ask for another forecast.

In general, for extended offshore passages, clients request 2-3 forecasts per week.

I've worked with self-reliant folks who only needed 1 general 10-day outlook each week on their trans-Atlantic passage, to help ensure they were at about the optimum Latitude, and not at risk for a severe storm. These clients can cross the Atlantic on 4-5 forecasts for a total of $100-$150.

More typical is a client requesting 1 or 2 detailed 5-day forecasts per week, and 1 or 2 detailed 2-day forecasts the day before inclement weather...for a total of about $100-or-so per week.

30. Can you give me a waypoint to head toward?
Occasionally there's a good reason to aim for a specific waypoint, and, when this is the case, I'll give you a specific waypoint.

However, it is my strong opinion that clients are best served by sailing their vessel in a manner which is fast and comfortable, while heading basically in the right direction.

For instance, I had 2 clients heading from Florida to E Caribbean this week.

One seemed hell-bent on maintaining a due-E course in spite of strong SE wind, and he ignored or didn't understand my advice to sail "whatever course is comfortable basically to the NE-E". He got battered-up, turned around, and sailed 2 days back to Florida.

The other vessel was more-flexible, sailing generally NE-E, on a consistent beam reach in the brisk SE-S wind, and - he's now sailing nicely E-ward, with mild S wind and excellent prospects for a mild trip to E Caribbean with mild N wind next 2-3 days, before reaching NE-E Trades.

Again, there are situations where navigation is restricted, or where weather trends make sailing in a specific direction (and achieving a specific waypoint) imperative. More often, however, maintaining a comfortable sailing angle while going generally in the right direction is preferable.

31. Sharing forecasts with others
You are purchasing limited rights to use my intellectual property on your vessel and, unless you have my express permission, you may NOT redistribute, or cause to be redistributed, my forecasts for use on a vessel you are not physically on.

However, there are some ways you can share:

Feel free to put our forecasts into your own words, and share this with others. Be sure you note it's your interpretation of my forecast. Sharing our words is NOT OK. Expressing your own words is fine, as long as people don't think they're our words.

If you believe sharing one of our forecasts on a single occasion may motivate a potential new client to purchase our services, then it's OK to share OUR WORDS on that one occasion. However, this is NOT OK on a recurring basis, or if you do not think there's a reasonable chance the sharing could prompt the person you're sharing with to purchase services.

If you are aware of improper sharing of our forecasts, please let us know at: chris@mwxc.com

32. Position Reports
Many vessels have the ability to send Position Reports, and I find these useful in several ways.

I established a special email address for receiving Position Reports from clients. Please send (or copy or blind copy) Position Reports to: spot@mwxc.com

In order to match the Position Report to a client (so I can provide better service to you), I need one of the following in the SUBJECT LINE of the Position Report:

A. whatever characters are in the "SSB Call Sign" field of your account at www.mwxc.com (this can be an SSB or Ham Call Sign - but NOT BOTH).

B. the 4-digit "SPOT Email Identifier" field of your account at www.mwxc.com (a 3 or 4 digit number unique to your vessel, assigned by my system, with a "#" symbol before & after the number).

To find either of the above, login to your account at www.mwxc.com (if you don't know your username/password, click "Retrieve Your Login Information" from the Login page, and my system will generate a new password and email it to you).

When my system receives a Position Report at spot@mwxc.com it attempts to match words in the SUBJECT LINE of the Position Report to the "SSB Call Sign" and "SPOT Email Identifier" fields of your Client Profile.

Once a match is made, your position is plotted on an interactive map I use to track clients and monitor real-time weather information. See the FAQ on Interactive Weather Map.

In addition, my system attempts to "parse" any weather observation details your Position Report may contain into numerical data, which it graphs for me, so I can see recent weather observation details throughout the area.

And my system displays (and I read) any additional text/comments from your Position Report.

Position Reports can be submitted by any combination of:

SPOT device from Glogalstar (Original SPOT, Spot Connect, SPOT G3), but the SPOT phone is just a phone, and not a position reporting device.

DeLorme InReach

WL2K

YOTREPS

Email via any method

Specific requirements for each are below.

33. Do you provide service for vessels Crossing the Atlantic?
Yes. I work with many vessels each year on both E-bound and W-bound Crossings of the Atlantic.

We can work via SSB Voice Nets, voice telephone, email, SMS text messaging, or any combination.

SSB Nets should work all the way to the Coast of Europe, depending on propagation and the quality of your radio installation.

No SSB? Many folks prefer email and/or voice telephone or have no SSB, so we can communicate via email and/or voice telephone or even SMS text messaging for any part of the trip.

Pricing:

SSB Nets $199, includes unlimited Daily contact, as often as 6 Days/week, but you just hail me when you want a forecast, there is no daily check-in requirement.

Forecasts by phone/email, as follows:
10 prepaid forecast credits for $250 may be used as follows:

phone-in ($25/call or 1 forecast credit)
email Detailed 5-day forecast ($65 or 2 forecast credits)
email Detailed 2-day forecast ($35 or 1 forecast credit)
email General 10-day Outlook ($35 or 1 forecast credit)

To purchase any of the above: visit www.mwxc.com and click any orange "sign-up" link, then complete and submit the form. Your order will process in real time and you will receive an automated confirmation email. If not, please call 863-248-2702 to place or troubleshoot your order.

34. How do I use your service on my upcoming ocean voyage?
We offer weather forecasting and routing advice via telephone, email, SMS message, SSB Radio, live interactive Internet Webcasts, and recorded forecasts. Basically, if you have any communications capability beyond VHF range, we can provide forecasts and routing advice!

SSB Voice (including simultaneous Internet Webcasts & recorded forecasts) is $99/mo or $199 for a year.
Add our Daily Regional EMail forecast for $100 for a total of $299/yr.

Alternatively (or in addition), we can work by voice telephone and/or email, as follows:

For some upcoming passages you may want a detailed 5-day email forecast prior to departure, then occasional vessel-specific email updates while underway. Order your initial 5-day email forecast anytime.

While underway, when you want a vessel-specific email forecast, please email me in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

You can purchase any/all of the above on my website www.mwxc.com (click any orange "sign-up" link, then complete and submit the form), or call me 863-248-2702 for assistance if you have questions...Chris

35. How do I use your service for Cruising the US E Coast and Bahamas/Caribbean?
(Updated Dec 11, 2023)
We have a couple different types of service, and you will probably benefit from a combination of them (we have COMBO packages combining services at a discount).

TO PURCHASE, visit

https://www.mwxc.com/signup.php

Complete and submit the form. This processes your order, and services begin immediately unless you specify a later date.

Regional Daily Email forecasts provide the information you need to make your own good weather-based decisions each day, and include some general travel suggestions. These are very cost-effective (about $1/day), but they are not specific to your vessel or itinerary. Regional Email forecasts will however greatly enhance your enjoyment of the Bahamas (and US E Coast and Caribbean), as you'll know when inclement weather is coming, so you can move in advance of it, and pick the right spot to shelter. And they'll help you use Custom forecast Credits (see below) more effectively, when you really need to work with a meteorologist one-on-one.

Custom forecasts are created just for your vessel and itinerary, working one-on-one with a meteorologist. You tell us where you are, where you're heading, when you expect to be ready to depart, and we work with you to find a good departure date/time. Once we agree on departure date/time, we email a detailed forecast, routing advice, and GulfStream info (if applicable) the day before departure (or in the morning if you're departing later in the day). Custom forecasts are $35-$95 (or 1-3 forecast Credits) each, depending on length and whether we're monitoring for a departure opportunity for an extended period of time. A 10-pack of Custom forecast Credits is $299, but 5 or 10 Credits are available at a discount as part of a COMBO.

More info on Custom forecast and Credits here:
https://www.mwxc.com/faq.php#q26

A 2-day Custom Email forecast perfect for any trip of less than 3 days, and runs $40 (or 1 Custom forecast Credit), or $65 (2 Credits) if we're monitoring and communicating with you for as long as it takes to find a good departure.

If you are planning a series of short hops, then we will do one 2-day forecast at a time, as needed until you complete your trip.

A 5-day forecast is perfect for a longer nonstop trip of 3 or more days, and runs $70 (or 2 Custom forecast Credits), or $95 (3 Credits) if we're monitoring and communicating with you for as long as it takes to find a good departure.

You will use our Regional Daily Email forecasts (in addition to any apps you like) to make your day-to-day weather decisions. And when you feel the need for one-on-one assistance (maybe you have fair weather friends onboard, or you are having trouble finding an opportunity to make a move, or you have a deadline to get somewhere), then you'll request a Custom forecast.

We also do live, interactive Webcasts (simultaneously with our SSB Radio Nets) 2x/day (mornings and evenings). You text questions into the chat box and we answer your questions (and any follow-ups) verbally, while also sharing our screen, so you see the weather we're describing. You may feel this is overkill, but many clients like the visual aspect.

Please review this flyer to help you decide what to purchase, and if you want to discuss on the phone, we can talk about it as well (call 863-248-2702, any day after 10am Eastern time):

https://www.mwxc.com/images/MWXC-Flyer-services-offered-202210.pdf

Examples of COMBOS you may want to purchase:

1yr Regional Email + Webcasts/SSB + 10 Credits ... $569
1yr Regional Email + Webcasts/SSB + 5 Credits ... $449

1yr Regional Email + 10 Credits ... $439
1 yr Regional Email + 5 Credits ... $329

3mo Regional Email + 5 Credits ... $229

Other COMBOs available.

36. I purchased a package of 10 pre-paid forecasts. How do I get a forecast?
You purchased 10 prepaid forecast credits. They can be used as follows:

You probably want a pre-departure detailed 5-day forecast . When you have some idea of the date you'll be ready to depart, please call or email me to schedule the initial forecast. I typically send forecasts the day prior to your departure. But if you need more pre-departure planning, I can schedule forecasts farther in advance.

When you want another email forecast, please email me the following in the morning and I will email your forecast later in the day:

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)
d. If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am EDT/AST

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250).

If you have questions, let , me know...Chris.

37. Pacific Ocean - do you provide forecasts, or know someone who does?
Updated Feb 14, 2024:

Yes, we provide Custom forecasts and routing advice throughout the Pacific, Indian, and Atlantic (as well as the Mediterranean, North Sea, etc).

If you're heading from Panama across S Pacific to NewZealand or Australia:
We try to send Custom forecasts at the appropriate time so you have a new forecast sufficiently before any change in weather / routing, so you have time to respond before any inclement weather or significant change in routing.

You'll want a 5-day Custom forecast prior to departure (2 Credits), and if we are monitoring weather for more than a few days to find a good departure opportunity, it would be 1 additional Credit for as long as it takes (a week or many weeks) to find a good departure time. With the present weather pattern, you may not need to wait long for a good departure opportunity, so Departure Planning may not be necessary.

About 3 days into the trip, you probably want either a 2-day or a 5-day forecast (1 or 2 Credits) to refine forecasts / routing until you reach the prevailing S backing SE winds of the S Hemisphere (or until you reach Galapagos if stopping there).

Once you're embedded in the prevailing S backing SE winds, you have a choice: continue with detailed 5-day forecasts with 10-day Outlooks (2 Credits) about once every 4-7 days - OR - switch to "General Outlooks" which provide a Synopsis of weather features and their influence on you, a bit of detail regarding any significant weather events, sea surface currents, and optimized routing (1 Credit about every 5-8 days).

Either way, if weather is very settled and straightforward, then (1) 10-pack of Credits should be sufficient to reach Marquesas, and if weather is more complex and problematic, then you might need a couple more Credits, but it might still come in within the 10 Credits.

For the rest of your trip across the Pacific, for most hops you'll just need the pre-departure forecast (2) Credits, and maybe (1) 2-day forecast (1 Credit) en route for longer passages. One additional 10-pack of Credits should get you at least to Tonga or Fiji.

Then probably a 3rd 10-pack of Credits for a trip to NewZealand or Australia, and you would probably arrive with Credits remaining, which you could use the following season for a trip back to Tonga, Fiji, or NewCaledonia.

So I would guess somewhere between 25-30 Credits over the next year to get to Australia or NewZealand. More or less depending on how often you need forecasts.

38. Is your book, Coastal & Offshore Weather, the Essential Handbook, available as an E-Book?
No, but I'll be glad to ship you a printed copy.

I spent hundreds of dollars having the book converted to a Kindle E-book, and the finished product was so bad I couldn't sell it.

Kindle is great for text-only books. But books heavy with images (as mine is) are a problem...and, if I spend thousands of dollars on a good Kindle rewrite (assuming that's even possible), Amazon's pricing model is such that I'll never get my money back.

E-books are great for high-volume, text-only books.

My experience is that it's horrible for graphics-heavy, low-volume books.

39. Evening SSB Nets?
Afternoon Net is at 2200 utc on 8.137 & 12.350 USB. When there's not a lot of traffic (July-April) we come on the air at 2200 utc, ask for Emergency/Priority traffic, then call for any Subscribing Vessels wanting weather info. We typically start in the W Caribbean (since that's where antennas were turned in on the last morning Net)...then work into Bahamas/E Caribbean...then waters N of Caribbean...then US E Coast & NW Atlantic.

All of this typically takes 15 minutes, then we're done...so there are no set times for pointing antenna in any direction.

During busy months for long-range passages to Europe (May-June) the evening Net may take an hour or more. When this happens, we come-up at 2145 and build a list of vessels with traffic for Marine Weather Center, then, at 2200 utc, we begin working the list of vessels with traffic - in the most logical order.

Propagation in the evenings is typically better (and longer) than mornings, and this Net is geared more to passagemaking than to vessels making day-hops, but it is open to any Subscribing Vessel. Also, Florida and areas within 100 miles of Florida are problematic because we skip over each other on 8-megs & 12-megs.

40. Satellite text messaging devices (Garmin InReach / Explorer, Spot-X, Zoleo, ACR BIVY Stick, and satellite phones (Iridium, Iridium GO!, Globalstar, Inmarsat, iSatPhone))
Satellite text messaging devices (Garmin InReach / Explorer, Spot-X, Zoleo, ACR BIVY Stick, and satellite phones (Iridium, Iridium GO!, Globalstar, Inmarsat, iSatPhone))

We can send Custom forecasts and routing advice via text to all of these devices, but you should understand how these work, and have reasonable expectations. Some systems have additional limitations (discussed below), and it's really important that you understand NONE of these allows sending or receiving of conventional email! Some provide an email address for communication, but this simply uses email to deliver a short text message (the difference between email and text messages via email may not seem important, but it is, as text messages via email can not contain subject lines, signatures, or replies to previous messages, and must not exceed certain characters in length).

We should also test 2-way communications before you depart.

The following devices use the Iridium network to send / receive messages: Garmin InReach / Explorer, Zoleo, BIVY Stick, Iridium phones, Iridium GO!. The Iridium network is very reliable constellation of satellites in a Low Earth Orbit (LEO), about 500 miles up, and uses a MESH network to interconnect satellites, providing connectivity everywhere on earth as long as your device has a clear view of the sky. Messages take from a few seconds to a few minutes to send / receive.

Of the above, the easiest to use, and the ones we most highly recommend are: Garmin InReach / Explorer, and Iridium GO!. Both pair with your Smartphone. Before you depart you download and open the appropriate App on your Smartphone (and for the Iridium GO! you also download the texting App onto the Iridium GO!).

Pair your Smartphone with your satellite device, and you compose, send, receive, read, and respond to messages via your Smartphone, using the satellite device as a "dumb terminal" to communicate with the satellite network.

Messages must be plain text, and 160 characters or less, but we can send forecasts in multiple messages.

*.*

Garmin InReach / Explorer:
Lots of options / capabilities, but some are not enabled by default. Specifically, you can send your position to anyone, but this may not allow recipients to communicate with you. There are at least 3 ways outside users can communicate with you: via MapShare, with a LINK contained in a customized message you send to them, and by sending a specially formatted message via email.

MapShare: info on setting-up MapShare is here:
https://support.garmin.com/en-US/?faq=p2lncMOzqh71P06VifrQE7

In order to enable and properly configure MapShare, you login to your account here:

https://explore.garmin.com/Account/LogOn?ReturnUrl=%2f

Then under "Social", make sure MapShare is turned ON. Then, under MapShare Settings, make sure you elect to: "Allow map viewers to send you messages" (this may be turned OFF by default, and unless you elect to allow map viewers to send you messages, we will not be able to send you a forecast via MapShare.

It is helpful if you use MapShare, and send us your MapShare link (but MapShare is not the BEST way for us to send you messages).


THE BEST WAY to ensure we are able to send you messages is to compose a message on your Smartphone's InReach / Explorer App to:

chris@mwxc.com

And ask us to reply to your message. You can send messages to email addresses, but if you can not figure out how to do that, you can send to my cell phone #: 941-915-7608. However, sending a position link is not sufficient. You must actually compose a custom message to us. We suggest you ask us to reply to your message. When you receive our reply, you will know we have established 2-way communication. The custom message you send to us will look like this (you can send one to yourself to see it work):


*.*

Please reply to this message…Tom.

View the location or send a reply to Tom Smith:
https://explore.garmin.com/textmessage/txtmsg?extId=08dab2d2-0f44-71c6-000d-3aa79c1982740&adr=chris%40mwxc.com

Tom Smith sent this message from: Lat 27.930529 Lon -82.454431

Do not reply directly to this message.

This message was sent to you using the inReach two-way satellite communicator with GPS. To learn more, visit http://explore.garmin.com/inreach.

*.*

That long "https://explore…" LINK is what we will save to your client profile, and it allows us to text you even if your MapShare is OFF, or does not allow outside users to send messages via MapShare.

One reason messages via the above type LINK are best is we compose our message to you via an online portal in a web browser, and this has a character counter (so we know our message is an appropriate length), and when we send the message there's a verification process which ensures your message is accepted by the Iridium network for sending. This is the ONLY METHOD of sending you a text with these nifty features.


The last option is email. InReach assigns your device a unique email address, such as: tomsmith@Inreach.garmin.com

InReach transfers messages to/from your unit via short text message, and NOT via email. When someone sends you a message via your InReach email address, the server at InReach parses the email and extracts up to the first 160 characters of text, and sends this via text message to your device.

But there are lots of things in an email we send you that can cause errors on the Iridium delivery network, which will prevent you from receiving the message, and we get no feedback the message failed.

*.*

Iridium GO (and other Iridium phones):
We will need your 16-digit phone #, which begins with an 8816. Some Iridium service resellers buy bulk airtime from Iridium, and assign you their own phone# which does not begin with an 8816. We need the number beginning with an 8816, which you should be able to find in your documentation even from bulk resellers.

Iridium GO! Works great, as you compose and view messages on your Smartphone's App, much like with Garmin InReach / Explorer.

Handheld Iridium phones also send and receive text messages, but it's a difficult process composing messages via the numeric keypad on the phone, and viewing received messages on the small LCD screen on the phone.

*.*

Zoleo:
Works much like the Iridium GO! and Garmin InReach / Explorer, but if we are both using the Zoleo App, allows messages up to nearly 1000 characters.

It is easiest for us to send messages via email to your Zoleo device, and for this we need your Zoleo email address, which will look something like this (obviously not "tom"):

tom@zoleo.com

If you supply your Zoleo's phone#, we can communicate via the Zoleo App on our end as well, and send/receive longer messages.

*.*

ACR BIVY Stick:
Works much like the above, you supply contact info, and we can communicate with you via short text message.

*.*

The following devices use the Globalstar network: SPOT-X, and Globalstar phones.

This network has individual satellites in low earth orbit (LEO), about 500 miles up, which bounce your traffic directly to the nearest ground station, but each satellite operates independently (there's no MESH network), so it works only when you are within about 1500 miles from a ground station, and there are many places on earth without ground stations, so this network is most useful for Coastal and near-shore use, and only in areas with a ground station which is functioning properly.

Due to design and other issues, the Globalstar network is not as reliable as Iridium, but text messages are delivered fairly reliably, and usually within a few minutes - if you're in an area with service.

Text messages are limited to 140 characters. You supply your contact info, and we can communicate via really short text messages.

*.*

The following devices use the Inmarsat network: iSatPhone, and Inmarsat phones. This system uses relatively fewer satellites (14 total), placed in high geo-stationary orbits about 22,000 miles up. Because satellites are so high, and orbit over the Equator, they use spot beams to focus signals into the most used areas. Communication is possible nearly worldwide if you have a large external directional antenna, but the handheld iSatPhone works best within about 40-50 degrees of the Equator.

Otherwise, this works similarly as other satellite text messaging devices.


*.*

Below is a SAMPLE of what we can send to your satellite text messaging device:

Recently we sent the following detailed forecast for a vessel on passage via his InReach...this forecast took 5 InReach messages, but for short-term Coastal sailing we can usually keep it to 1-3 InReach messages and still convey a very good, specific forecast and advice.

We charge $40-$70 per forecast or $299 for (10) forecasts, good for a year. Regardless how many messages it takes us to convey the information, we only charge you for 1 forecast:

*.*

You are getting into GulfStream, and there is NO PROBLEM with lying farther E than intended.
SUGGEST you try to maintain Course Over Ground 360T.

You will EXIT GulfStream along a LINE:
38N/68W
38-15N/67-40W
Once out of Stream, aim for SalemMA.
Tonight: 240@16-20g25, squalls/T-strms 30-40k, 6-9'.

It is OK if you sail whatever course is comfortable, even if that's slightly E-of-N in terms of Course Over Ground.

N of GulfStream Mon10: variable mostly S-SW@0-15, 2-4', you may need to motor/motorsail.
Mon10 night: becoming steadier 230@10-15g20, 2-4'
Tue11: 210@15<23g30k

Tue11 night: 230@23g30, 8'
Wed12: N of 42N falls L&V, motoring toward Salem.
Thu13: uncertain, IMPULSE or LO moves ENE from NewEng, but weather will be OK.

*.*

Purchase at www.mwxc.com by clicking any orange "sign-up" link, then complete and submit the form (you want the 10-pack of Custom phone-in forecasts for $299).

41. Typical seasonal weather in E Caribbean
From about mid-December thru most of March weather systems to the N are amplified...and the big / strong areas of HI pressure to the N drive your brisk Trade wind / seas.
During this time there are intervals of milder conditions (lasting from a couple days to a couple weeks), and you should use those intervals to move. We had a couple weeks in late January where conditions were very mild (even too light for sailing) for most of 2 weeks.
Late March thru early June brings changeable weather...with more frequent & longer-lasting intervals of very light winds/seas as the sub-Tropical RIDGE is pressed S into the Caribbean. The direction of Trades also usually begins shifting from ENE to E-ESE....and in May-June squalls begin becoming more significant with weak TropicalWAVEs.
June thru September we get into a pattern of squally TropicalWAVEs with 1 day of really nasty weather with wind veering NE The other thing common in May-June is early-season W-moving TropicalWAVEs reach the Caribbean and interact with E-moving weather just N of the Caribbean...and this sometimes causes TropicalWAVEs to stall & linger for days or even a week. We can see day-after-day of heavy rain and strong wind in squalls...not a huge deal if you're in a protected anchorage, but this causes rock & mud slides on mountainous islands.
In the absence of stalling TropicalWAVEs, May-June tend to be pretty nice months.

42. Crossing Atlantic
Yes, we provide forecasts and routing advice via email, phone, text, and SSB Voice.

We can communicate via SSB Voice Nets for $199 for the entire trip (or for as long as propagation allows which should be most of the trip).

Alternatively (or in addition), Custom forecasts by email, voice telephone, and text message for $30-$65 per forecast, or $250 for a 10-pack of Custom forecast credits.

Most boats rely on us to supply about (2) detailed 5-day Custom forecasts each week, and occasionally a detailed 2-day Custom forecast before any major decisions or high-impact weather events (about 4-5 Custom forecast credits per week).

But we also offer just a General Outlook for those who want to do most of their own day-to-day forecasting work. Below are more details, and you can request whichever suits your needs on a particular day:

1. The 10-day Outlooks are just a high-level overview of the Synoptic weather pattern, and SeaSurfaceCurrents, and give a couple suggested Waypoints, and some detail on 1 or 2 instances of significant weather expected in that 10-day timeframe. You handle your day-to-day detailed forecast on your own. You request from us maybe (1) 10-day Outlook each week (using 1 Custom forecast credit), to ensure you're basically heading in the optimum direction.

2. Detailed 5-day forecasts include the 10-day Outlook (so you do NOT need to order the 10-day Outlook), PLUS a detailed 5-7 day wind forecast, including more waypoints, sailing strategy suggestions, detail on seas and squalls. This uses (2) Custom forecast credits, but we do all the forecasting work for you (so you don't need to do forecasts on your own, but we encourage you to do as much forecasting work as possible so you have a deeper understanding of the weather situation), You probably need just 2 of these forecasts per week, on average (more frequently if weather is dynamic).

3. Detailed 2-day forecast (1 Custom forecast credit) includes just the next 2-3 days in detail, and is best used to refine forecast and routing advice for an upcoming Decision Point along the voyage or a high-impact weather event.

Again, most vessels request about (2) of the detailed 5-day Custom email forecasts each week, so for the entire trip to the US plan on (2) of the 10-packs of Custom forecast credits for a total of $500.

Purchase the 1st 10-pack at www.mwxc.com by clicking any orange "sign-up" link, then complete and submit the form, or call 863-248-2702 and we'll assist over the phone.

So we're here as much or as little as you feel you need us....and we look forward to working with you...Chris.

43. Hurricane Season 2020 options
Indeed, we published something you might find very useful...it's on our website here:
https://mwxcblog.com/tropical-season-2020/

Our article is also on www.Noonsite.com and will be in the Caribbean Compass magazine in May.

Staying in the Caribbean is a viable strategy.

Some clients have checked with local customs/immigration, and verified that, if they depart and go sailing for a hurricane, and never make landfall anywhere else, they will be allowed back into the island from which they departed.

You may want to verify that's allowed where you are.

The strategy for what to do in a given situation when there's an approaching Tropical LO depends on many things, and is best addressed with each vessel when the time comes.

We are offering to monitor weather for you, and let you know when we think there's a meaningful Tropical threat, and then provide a pre-departure forecast and routing advice to evade the threat. Cost $65, and the product is our detailed 5-day Custom email forecast.

To purchase:
If you have an account, please login then click the SIGN-UP NOW FOR NEW SERVICES link.
If you are a new client, visit www.mwxc.com and click any orange "sign-up" link, then complete and submit the form.

Let us know how we can help...email chris@mwxc.com or call 863-248-2702...Chris.

44. InReach / Zoleo / satellite text message (Iridium, Inmarsat, Globalstar SpotX)
Forecasts by InReach and Zoleo and other satellite text platforms:
We suggest a 10-pack of Custom forecast credits, good for a year for $250. We would use (2) credits to schedule a detailed email forecast to be sent prior to departure, and this includes helping you select a suitable departure day/time, weather synopsis, detailed forecast, routing, and GulfStream info if applicable.

While underway, you will already be heading in the right direction, and you'll already understand the large scale weather pattern and the portions of your voyage on which we need to focus most attention, so we can keep forecasts to your InReach (or Zoleo or other satellite text messaging) more brief.

While underway you message us from your InReach (or Zoleo or other satellite text messaging) to:

chris@mwxc.com and include the following:

1. location, course, speed (and sail configuration if relevant)
2. weather conditions
3. request a forecast and ask any questions you want us to answer. The more specific you are with questions, the more useful our answers will be.

We will then message you a forecast, updated routing, and include answers to any questions you asked (delivered in several short text messages).

TO PURCHASE:
Visit www.mwxc.com then click any orange "sign-up" link then complete and submit the form, or call 863-248-2702 anytime after 10am AST/EDT. For a product, select under OPTION #4: CUSTOM FORECASTS, either 10-pack of Custom forecast credits for $250.

If you prefer, instead of a 10-pack of Custom forecast credits, you can purchase a single forecast for $35 (purchase a Custom 2-day email forecast, $35).

MORE INFO about InReach (and Zoleo):
These devices send short text messages via the Iridium constellation of satellites. Messages are text only, and very limited in length.

Both InReach and Zoleo developed ingenious frameworks to support some interaction by email - but the underlying message delivery via satellite is NOT email (it's short text message max 160 characters). Some forms of Zoleo communications (using the Zoleo app) can combine several short text messages to deliver 1 longer message.

Particularly InReach has many "gatekeeping" protocols which, when turned ON prevent unwanted SPAM messages - but they can also block sending messages you really want to receive.

IMPORTANT:
Anytime PRIOR TO DEPARTURE, we need to test the InReach (or Zoleo or other satellite text messaging) as follows:
Message from your InReach (or Zoleo or other satellite text messaging) to: chris@mwxc.com

(If via InReach, then the message we receive contains a LINK we'll save, allowing us to message you anytime in the future. This LINK bypasses all the "gatekeeping" measures.
If via Zoleo or other satellite text messaging, your test message contains the number we can use to text you in the future.)

When you message us at chris@mwxc.com please ask us to reply.

When you receive our reply, you will know we have established reliable 2-way communication.


*.*

Below is an exchange we had with a client recently. He is without engine, and trying to get from E of the Abacos to BeaufortNC. This is longer than a typical exchange, but it's an example of a complex forecast and routing solution via InReach...Chris.

His messages to Marine Weather Center:
26-30N/76W, course 302T, 1.4k

Can you plse advise best strategy for destination Morehead City sail only at 4.5k avg

NO ENGINE No heading at this time but we understand wind will pick up Tuesday night Destination Morehead City

*.*

OUR FORECAST:
Although BeaufortNC is only 500 miles away, it is going to take you a week to get there, because mostly wind on the nose or no wind, and only brief intervals of

favorable wind.
In General:
Tue5 night S wind establishes, veers SW Wed6, then FRONT brings brisk NNW wind Dawn Thu7, veers N Thu7 night.
No wind Fri8.

Fri8 night S veering SW wind, but N wind Sat9, veers NE Sat9 night, light E wind Sun10, no wind Sun10 night into Mon11.
Wind is briefly SW Mon11 evening, but

N behind another FRONT Mon11 night into Tue12 morning, then no wind again Tue12 afternoon, and N-NE wind again Tue12 night-Wed13.
Building E wind Thu14.

Do you maybe want to select another destination? Somewhere in FL? Or maybe CharlestonSC?
Short term forecast:
Tue5 overnight: building from 150@8 to 190@11.

Wed6 builds from 190@11 to 220@10-14g17, STRATEGY: tonight-Wed6 sail course 330T.
Wed6 evening, near 28-15N/77-05W: veering 240@15g20.
Wed6 overnight: veering

from 240@15g20 with a few brief squalls to 40k, then 320@20-23g30 behind FRONT, STRATEGY: sailing 330T then 030T.
Thu7, near 29-30N / 76-45W: 330@20-23g30

settling to 17g22k.
Thu7 night, 30-30N / 75-50W: 340@16g20 veering 360@12 then falling L&V, sailing 045T then 060T then drifting.
Fri8, 30-45N/75-30W: L&V then

S@16, sailing 340T.
Fri8 night, 31-20N/75-40W: building from 200@17 to 250@25g35, sailing 340T.
Sat9 morning veers 330@25g35 and U sail NE so U R near 32N/75W.

During the day Sat9 wind veers N and settles to 15k, U sail 060T.
Sat9 night wind veers NE-ENE and U TACK and sail NW to 32-45N / 75-30W, then Sun10 wind may

die.
I am concerned if U get into GulfStream this far E, and with no wind, then U may be swept past Hatteras.
Therefore, DECISION POINT is Thu7 when U could

make decision to TACK and sail W as wind veers to NNW, and aim for Charleston.
Or U could head as much to the W as possible at all times and maybe make N FL?

This is msg 13 of 13. Any questions?...Chris.

45. After arrival
Congratulations on your safe arrival!

We'd love to continue providing weather forecasts and routing advice for your further travels.

We provide forecasts and routing advice for sail and power vessels worldwide, with 3 distinct offerings:

1. Custom forecasts, just for your vessel and itinerary - you let us know where you are, where you're heading, and when you hope to depart...and we help you choose a departure date/time then provide a detailed forecast and routing advice including details on currents, squalls and fog if relevant (more detailed and more specific to your needs than we supplied on the Salty Dawg Rally).

Geography covered = the entire world. Forecasts via email, phone, text, interactive Webcast, at a time convenient for you. Cost $30-$65 depending on length of forecast, or 10-pack of Custom forecast credits for $250.

2. Alternatively (or in addition) economical Regional Daily Email forecasts, covering the Caribbean, Bahamas and entire US E Coast as far NE as ShelburneNS. While these forecasts are not specific to your vessel, they should provide the information you need to make good weather-based decisions. Includes unparalleled coverage of Tropical systems throughout the Atlantic. Cost $199/yr, $99 for 3mo, or $55/mo.

3. Custom forecasts and routing advice via SSB Voice Nets and simultaneous Internet Webcasts. We can discuss departure timing, forecast, routing, currents, anything else you wish - just for your vessel and itinerary - mornings from 6am-9am and for a few minutes at 6pm. Cost $199/yr, or COMBINE with Regional Daily Email forecasts for $299/yr total.

To purchase any of the above, login to your account at www.mwxc.com and click the SIGN-UP NOW FOR NEW SERVICES link, or call 863-248-2702 any day after 10am EDT.

We look forward to working with you on your next move...Chris.

46. Definitions: TROF, RIDGE
TROF: A TROF is any area of lower pressure which is elongated along an axis.

LO pressure system is symmetrical (round) or elongated / somewhat of an oval shape, and wind circulates around it in a counter-clockwise direction.

A TROF is an area of lower pressure which is flat - it lies along an axis...and air tends to flow toward that axis, as well as moving upward in altitude.

Examples of TROFs include ColdFRONTs, WarmFRONTs, StationaryFRONTs, TropicalWAVEs, and others.

If we simply use "TROF" by itself, then it is typically a boundary in the atmosphere along an axis (say from 30N/40W to 25N/50W), and it is neither a WarmFRONT (advancing warm airmass), nor a ColdFRONT (advancing cold airmass), nor a TropicalWAVE.

Because air along a TROF is converging toward the TROF, and also rising in altitude a TROF tends to bring cloudy unsettled weather and it can be squally.

*.*

RIDGE:
An area of HI pressure is symmetrical (round) or oval in shape, and air flows around it in a clockwise direction.

A RIDGE is a flattened (very elongated oval) that's not as strong as most more-symmetrical areas of high pressure.

RIDGEs and HI pressure systems are characterized by sinking, downward-moving air which diverges away from the RIDGE at the surface.

This sinking air tends to be fair and stable (fewer clouds and no squalls) - except in warm, moist environments pockets of convection (parcels of air warmer than surrounding environment) can overcome the broad downward-moving airmass and still produce thunderstorms.

47. Concerned about Tropical LO pressure systems in the Caribbean, Bahamas, or elsewhere?

We offer a service where we monitor possible Tropical threats, and if we identify a threat to your location, we'll contact you to establish a dialog.

We normally classify a threat as any meaningful chance an approaching Tropical LO (or potential Tropical LO) could bring you TropicalStorm (35k+ sustained) winds from any direction, or more than 10k of wind from a direction from which you might not be protected.

Cost is $65 (or 2 Custom forecast credits) to monitor and alert you to a possible threat, and to provide Regional forecasts which cover the potential threat as the system approaches. This also includes consultation on whether we recommend you take action ahead of the approaching threat.

IIf you decide to take action by getting underway to avoid the threat (or if you want a Custom forecast for where you are), your 1st Custom forecast is included at no extra charge. Additional Custom forecasts are $35 (or 1 Custom forecast credit), or a phone call is $30 (or 1 Custom forecast credit). You might need a couple of Custom forecasts immediately before and during the event.
When that Tropical threat has passed, we can schedule another monitoring type forecast for $65 for the next possible Tropical threat.

To get started, please decide whether you want to start with just a single $65 monitoring-and-alert forecast...or whether you want to purchase the 10-pack of Custom forecast credits (they're good for a year, details below).

If you do NOT have an account, please visit www.mwxc.com then click any orange "sign-up" link then complete and submit the form, or call 863-248-2702 anytime after 10am AST/EDT.

If you DO have an account, login to your account (if you do not remember your credentials follow the prompts to "Retrieve your login information"). Once logged in, either Renew your previous service or click the "SIGN-UP NOW FOR NEW SERVICES" link.

You may also request forecasts by email, phone, or text message.

FORECASTS:
If you want a forecast by phone ($30 or 1 forecast credit), call 863-248-2702, after 10am AST/EDT

Text message (including Garmin Explorer / DeLorme InReach): send to chris@mwxc.com (or, if you must send to a phone number, use 941-915-7608). Be sure to ask a specific question, so as can be sure to provide the best answer in the constraints of SMS messaging. Cost is same as 2-day Custom email forecast $35 or 1 forecast credit).

When you want an email forecast, please email us the following in the morning and we will email your forecast later in the day (we can also schedule these in advance):

#1: your location / course / speed
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($65 or 2 forecast credits)
b. Detailed 2-day forecast ($35 or 1 forecast credit)
c. General 10-day Outlook ($35 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $250. ANY forecast credit can be used for ANY Custom forecast, so purchase either 10-pack of credits for $250).

*.*

CONFIRMATION:
Your Tropical weather monitoring is ON, for Martinique.

If we identify a threat to your specific location from a declared Tropical LO (or anything that might become a Tropical LO), which might bring 35k+ sustained winds, or 10k+ winds from directions you're not protected) we will:

1. email you to initiate a dialog about the timing, probability, and potential magnitude of the threat.
2. turn ON our Regional Daily Email forecasts for the duration of the threat.

You have a FREE detailed 2-day email forecast, text message, or phone call on your account to use anytime in the next 12 months.

If you decide to take action by getting underway to avoid the threat, you might need additional Custom forecasts, and we can bill you for these only if/when you request them.

If there is a Tropical threat and we do as described above, then after that Tropical threat has passed, if you wish we can schedule another monitoring type forecast for $65 for the next possible Tropical threat. Hopefully there are no Tropical threats!

Please do let me know where you are, and if you move please login to your account and change the "JOURNEY / Embarking From" location to reflect your updated location, or email us and we'll update your location for you.

We look forward to assisting...Chris.

48. InReach for SDR
Forecasts will begin to your email address (NOT to InReach) about 5 days prior to departure, by email.

If you are using InReach (or other satellite text messaging device) for offshore communications. PLEASE test prior to our departure.

Send message from InReach to:
chris@mwxc.com
and ask us to reply.
After you receive our reply, you will know we can communicate.


When you want a forecast via InReach (or other satellite text messaging device), please message us the following info in the morning and we will reply with your forecast later in the day:

#1: course / speed
#2: weather / sea conditions
#3: ask a question so we know you want a response, and so that our response can be most relevant

When weather is settled, you should not need a forecast every day. Forecasts normally include suggestion on when we suggest you request another forecast.

*.*

Also,

1. Please change the SUBJECT LINE of your messages to include your boat name. This way, every time I get a message, I do not have to search for a person's name in our database to determine which boat it is.

2. When using particularly InReach / Explorer, please make sure the unit has acquired a GPS fix before sending message. Many messages come through with no position, and some positions on tracking map are delayed. If you ensure InReach / Explorer is sending position, then I'll know for sure where you are.

Cheers...Chris.

49. SDSA Wx Info "Push / Pull"
SDSA supplies me with initial information to add an account in our system for each participant. Sometimes your plans, communications capabilities, or other details change. In addition to updating SDSA, you should login to your account at www.mwxc.com to make changes, so we can provide support.

How we supply weather information ("push" versus "pull")

We "PUSH" information to Dawgs only by email and SSB Voice Nets.

If vessel does not have offshore email and/or SSB Voice, then vessel needs to contact us for weather information (think of this as "PULL" delivery). Part of a communication with such vessel is to suggest when the vessel should contact us to "pull" information again.

Several reasons for this:
SMS text (to InReach/Explorer, SpotX, Iridium or InmarSat phone): every message needs to be individually formatted just for that vessel, so the information is relevant, actionable, and deliverable. It is not possible to do this every day for every vessel, but they don't really need it every day except in "high impact" situations. Best information is in answer to a specific question (vessel asks us a specific question, and we provide a useful answer and anything else we think they need to know).

Voice phone: calling sat phones can be expensive, and phones are often only "on" and available to receive calls when the user is actively holding the phone. So for convenience and necessity, vessels call us, not the other way around.

Several situations have come up where a vessel got into a bad situation when they did not have access to any of our "push" information, and they failed to reach out to us to "pull" information....Chris.

50. DECCA Channel
ALL LOCATIONS are in degrees-minutes (and decimal minutes)....NOT degrees-decimal degrees!!!!
ALWAYS do your own navigation to ensure you remain clear of navigation hazards.
DECCA channel is a marked channel, and you can cut-off the corners on both the E & W sides, making sort of an "S-shaped" route, and is well detailed on the Explorer charts, but I would head from the BlackPoint / StanielCay area to:
24-14.5N / 76-45.0W
24-14.5N / 77-00.0W
Then head for NW ChannelLight, but make sure you pass W of the following point: 24-30N / 77-20W

51. How many Custom forecasts do I need?
How many Custom forecasts do I need when traveling from Bahamas or Caribbean to Europe?

The short answer to your question is typically 15-20 Custom forecast credits (10-15 forecasts). That's about $500.But it can be more or fewer, depending on the following:

How many emails depends on how complex the weather situation is, and how much of the forecasting / routing work you want us to do, and also what your weather tolerances are. Let me explain:

Complexity of weather:
If weather is straightforward, high confidence, and does not change much from day-to-day, then we may only need to do a forecast once/week (5-day Custom forecasts using 2 credits each). On the other hand, if we get a high impact and uncertain weather situation, then we may need to do a forecast once/day or even 2x/day for some short period of time (these would be short-term 2-day forecasts using 1 credit each).

Each forecast includes our recommendation on when we suggest you contact us for another forecast. We gauge this by assessing expected "inflection points" in the weather (when weather conditions are likely to change), and "decision points" along the voyage (when you need to make a weather-related decision), and we'll suggest you request a forecast sufficiently before such times that you have ample time to respond to the weather situation after receiving our forecast.

What about any changes in the weather, any surprises? We're really good at identifying when weather is uncertain or low confidence. While no one is always right about precise weather details every day, we can almost always anticipate uncertainties which could cause wide deviations from the expected weather. If you start to notice weather deviating meaningfully from the forecast, then please contact us, but this is very rare.

Forecasting / routing workload:
Some folks want to do some-or-most of the daily forecasting / routing work themselves, and retain us mainly to monitor the long term, big picture situation, so they are in about the right place at the right time. We do this with only the 10-day General Outlook (1 forecast credit), which does not include an actual forecast, but keeps them heading in the right direction.

Other folks (most clients) have us do all the forecasting and routing (though they may also download computer model weather forecasts so they understand the situation better and can ask better questions).

Weather tolerances:
Some clients want to know (so they can anticipate and plan for) small changes in weather conditions. Other clients are fine with wind as long as it's aft-of-the-beam and under 35k, and don't care too much about the fine details.

We're happy to tweak how we work with you, so you receive the forecast frequency and level of detail which suits your needs and budget.

52. Types of service (updated Oct 25, 2024)
Marine Weather Center offers 3 distinct services (most clients purchase a COMBO with 2 or all 3 types of service, at discounted price):
1. Custom forecasts via email, phone, text
2. Regional Daily Email forecasts
3. 2x daily (morning and evening) Zoom Webcasts (simultaneous SSB radio voice)

- Details on each service at end of this FAQ -

If you are a typical Cruiser in Caribbean, Bahamas, or US E Coast, living aboard for more than 2 months/yr, then a COMBO is probably your best choice - relying on our economical Regional Daily Email forecasts and/or watching the Webcasts to make your own good decisions most of the time, then either asking for vessel-specific guidance in the Webcasts or requesting a Custom forecast (by email, phone, text) when you want personalized input from an experienced meteorologist.

Here's how clients use our services:
Most clients have 4 modes: passagemaking, daytime / overnight hops, stationary, and off-the-boat. Some prospective clients may not appreciate the extent to which good weather planning enhances your life onboard for day hops or even when your vessel is stationary - we offer value added solutions!

Passagemaking: Custom forecasts via email, phone, text, and/or (a separate service) Zoom Webcasts / SSB radio voice

Day / overnight hops: any / all 3 services

Stationary: Regional Daily Email forecasts and/or Webcasts

Off-the-boat: no need for forecasts, unless you're curious - then use same service(s) as you would when Stationary

If you are a typical Cruiser in Caribbean, Bahamas, or US E Coast, living aboard for more than 2 months, you should benefit most from one of these COMBOs:

1yr Regional Email + Webcasts/SSB + 10 Credits ... $569
1yr Regional Email + Webcasts/SSB + 5 Credits ... $449

1yr Regional Email + 10 Credits ... $439
3mo Regional Email + 10 Credits ... $339
1yr Regional Email + 5 Credits ... $329
3mo Regional Email + 5 Credits ... $229

Other COMBOs (including shorter durations) available on Order Form and flyer describing services: https://www.mwxc.com/images/MWXC-Flyer-services-offered-202210.pdf

If you are outside of Caribbean, Bahamas, US E Coast, then you should benefit most from 1 of these 2 individual services:

10-pack of Custom forecast Credits ... $299 (or Custom forecasts 1-at-a-time)
1yr Webcasts/SSB ... $219

TO PURCHASE:
If you do NOT have an account, please visit www.mwxc.com then click any orange "sign-up" link, complete and submit the form, or call 863-248-2702 (or WhatsApp 941-915-7608) anytime after 10am AST/EDT (1400 utc).

If you DO have an account, login to your account at www.mwxc.com (if you do not remember your credentials follow prompt to "Retrieve your login information"). Once logged in, either Renew a previous service or click "SIGN-UP NOW FOR NEW SERVICES" link, or call 863-248-2702 (or WhatsApp 941-915-7608) anytime after 10am AST/EDT (1400 utc).

MORE DETAILS ON EACH SERVICE:
Custom forecasts (just for your vessel / itinerary, via email, voice phone, text message (including InReach and other satellite or cell phone text messaging)), include synopsis, forecast, routing advice, sea surface currents, and (optional) Departure Planning. Each 5-day Custom forecast (with 10-day Outlook if relevant) is $70 (or 2 Credits) / each 2-day Custom forecast is $40 (or 1 Credit). Departure Planning (we work with you for as long as it takes to find suitable departure opportunity) adds $25 (or 1 Credit). We also offer a 10-day General Outlook ($40 or 1 Credit) typically for vessels on long passages handling their own detailed forecasting, who just want a synopsis of major weather features / weather hazards and optimized routing.

For long passages, each forecast includes our recommendation when to request your next forecast - this is based on timing and magnitude of forecast uncertainty, and when we expect you to make weather-based decisions. You can request your next forecast sooner, but we do not recommend waiting any longer than suggested. In settled weather, you will probably want a new 5-day forecast every 3-5 days. In unsettled or rough weather (or when making a series of short daytime or overnight hops) you'll want 2-day forecasts every 1-2 days. Worldwide coverage, 365 days/yr. If you expect to use 8 or more Credits in the next year, then a 10-pack of Custom forecast Credits ($299) is a better value than purchasing Custom forecasts 1-at-a-time.

Regional Daily Email forecasts while not specific to your vessel / itinerary, do provide the weather info you need to make your own good weather-based decisions onboard each day, in the Caribbean, Bahamas, and along US E Coast. And also provide unparalleled coverage of Tropical weather throughout the Atlantic Basin (which may come in handy wherever you are during summer-fall Hurricane season). Daily except Sundays (will send forecast on a Sunday if there is Tropical or other severe weather). Cost $219/yr - shorter durations available but Annual plan is cost effective for most clients.

Webcasts / SSB radio: Live, interactive Zoom Webcasts work great worldwide (clients participate in Europe, S Pacific and elsewhere via Starlink or cell phone data connection (and SSB radio voice within 3000 mi of Florida via our HF station)). This service provides Custom forecasts just for your vessel / itinerary - you text questions into Webcast chat box (or hail us on SSB radio) and we answer questions and provide departure planning, forecasts and routing advice verbally. We share our computer screen, so Webcast participants see the weather we're describing - ideal if you are an audio / visual learner. Morning sessions start with 15-20 minute synopsis / forecast by area (E Caribbean, W Caribbean, Bahamas, US E Coast), and we record and upload this portion so you can watch / listen at your convenience. Evening session is just forecasts specific to your vessel / itinerary - faster and more convenient for vessels on passage than morning sessions which start with an area forecast. Daily except Sundays. Cost $219/yr - shorter durations available but Annual plan is cost effective for most clients.

We look forward to working with you, and we thank you for your support!...MWXC Team.

53. Example of Custom forecast Transatlantic
In the short term, after you passed N thru the FRONT there was a RIDGE / TROF / RIDGE pattern, with the sub-Tropical RIDGE S of the FRONT along about 26N / then of course the FrontalTROF near your location / another RIDGE NW of you, which caused your wind to be NE early Sat9.

During Sat9 afternoon-night that RIDGE shifted E, and is now centered near 40N / 40W….and as a result your wind has veered from NE
The 2 RIDGEs will merge, with the RIDGE near 40N / 40W shifting S&E into the sub-Tropics...and the next approaching ColdFRONT (which lies not too far away, about 300-400mi W of you) is supporting your S wind on Sun10 morning.

It's a fast-moving FRONT, but not strong, and it probably stalls somewhere near 32N or 33N Mon11 morning.

What to do next is a difficult decision.

If you move N into the wind N of the FrontalTROF (N of 33N) then an IMPULSE developing along the FrontalTROF W of you (almost a LO developing and turning the portion of the FRONT W of you into a WarmFRONT) will cause building ENE wind Mon11 afternoon, veering E Mon11 night...and this will force you to sail N info to stronger winds.

Fortunately, this IMPULSE shifts NE quickly, and as it passes N of you your wind veers from E to S Tue112, and you can head more to the E. This is lots of close reach sailing, but wind generally under 20k.

Wed13-Fri15 wind is mostly S
Alternatively you could motor E Sun10-Mon11, and then Mon11 night-Tue12 you would see wind veering from SE@7-12 to S@7-12, allowing you to sail ENE-E, and continuing S
With either of the above options, you would arrive near 35N / 38W on-or-before Fri15, staying ahead of the approaching ColdFRONT with wind SW@15 Fri15.

Then that FRONT probably passes you or weakens and wind becomes light for about 24-48hrs.

And this is followed by a stronger LO pressure system tracking ENE-E thru 45N/40W Sat16 night-Sun17, and this rebuilds your SW wind, which should carry you all the way to Horta (or very close).

The decision which way to go Sun10-Mon11 is very difficult in large part because there's uncertainty with how far S the FRONT presses Sun10 night-Mon11 morning before stalling. If it stalls near 34N, then if you are forced to sail mostly N for 24hrs thereafter, you could end up too far N.

So, after much deliberation, I'm going to suggest heading generally NE and E, probably staying S of the FRONT thru Mon11, then sailing from late Mon11 night-Fri15 on a nice reach in mild conditions.

FORECAST:
Sun10, near 32-30N / 49-30W: variable probably S-W@6<240@10-12, wind-chop 1'<2', STRATEGY: you could either drift N or E on whichever tack generates best apparent wind, or, if there's not enough wind for sailing, I would probably motor slowly on course 060T. I'm going to guess wind is really light most of the day, and you motor 060T most of the day, then sail 030T with wind 240@10-12 late afternoon.

Sun10 night, near 33N / 48-40W: 250@10-12
Mon11, near 33-20N / 47-50W: variable wind becoming mostly E but well under 10k, 0-1', Swell builds from 4'<8'/14secWNW. STRATEGY: motoring slowly course 060T.

NOTE: if FRONT passes you at any time Mon11-Tue12, and wind builds over 10k, I would:
--if wind is N of 070T, then I would sail close reach on Port tack (SE course).
--if wind is S of 070T, then I would sail close reach on Starboard tack (course N-NE).
--realize that over time wind will veer toward S, so you if you start on Port tack, you will soon switch to Starboard tack.

Mon11 night, near 33-40N / 47W: wind builds 090@7<090-110@10, wind-chop 1'<2', Swell 8=9
14secNW. STRATEGY: as wind builds toward 10k you begin sailing close reach to NNE.

Tue12, near 34-30N / 46-20W: wind builds and veers quickly, mostly 090-110<150@10-15g20, wind-chop 2-4', Swell 9'<7'/12secNW. STRATEGY: sailing close reach to the NNE
Tue12 night, near 34-40N / 45-05W: 150<190@12-15g19, wind-chop 3-4', Swell 7'<5'/12secNW. STRATEGY: sailing close reach
Wed13, near 35N / 43-50W: 190<220@12-15g18, wind-chop 3-4', STRATEGY: sailing beam reach
Wed13 night, near 35-10N / 42-25W: 220@12<200@12-15g20, wind-chop 3'<3-4', STRATEGY: same.

Thu14, near 35-20N / 41W: 210@12-15g19, wind-chop 3-4', STRATEGY: same.

Thu14 night, near 35-30N / 39-30W: same.

Fri15, near 35-40N / 38W: 220@14-17g22, stray squalls to 30k, wind-chop 4-6', STRATEGY: same.

Fri15 night, near 35-50N / 36-30W: 240@15-20g25, more scattered squalls to 30k, wind-chop 4-7', STRATEGY: same.

Sat16, near 36N / 35W: ColdFRONT pases, wind either dies (and you motor toward Horta) or there may be some N-NNE wind N of FRONT, which forces you to continue sailing E until wind dies.

SUGGEST you request another forecast no later than Thu14, so we can fine tune passage of FRONT about Sat16, and make sure you're properly positioned for approach to Horta.

To make sure we have answered your questions regarding motoring...other than motoring for 1-2 days from Sun10-Mon11 night and maybe 1-2 days approaching Horta, you should have good wind for sailing.

If you have questions, let me know...Chris.

54. Typical Spring routing from NE Caribbean to US E Coast
There is no reason to expect a May 1 departure would be problematic - though the later you depart, the easier the trip usually is.

Most likely the suggested routing will be to depart the Virgins pointing generally NW (toward N Florida)...then we should work together to pace your trip so that as you enter waters between Bahamas and SE US Coast, conditions are suitable to turn N and cross GullfStream.

Weather S of about 30N in May is typically benign most of the time, with a brief interval (from a few hours to a day) of adverse conditions associated with a ColdFRONT.

However, conditions in and N of the GulfStream and other areas N of about 31N (so basically N of a LINE from the FL / GA border to Bermuda) weather has longer intervals of more-adverse weather, with more-brief intervals of benign weather.

Thus, the strategy we're most likely to recommend is to get as close to any suitable Port as possible before getting N of a LINE from about the FL / GA border to Bermuda...

And to time crossing of this LINE to maximize the favorable weather N of this LINE.

Of course it's possible we get into a really settled weather pattern, and you can do a more direct shot to the ChesapeakeBay - we'll just have to see what things look like when you're ready to depart.

While our Regional Daily Email forecasts are great when you're in the E Caribbean, and along US E Coast...when you're offshore they will only discuss weather features in general terms. So for your offshore trip, we should be communicating one-on-one, with Custom forecasts (just for your vessel and itinerary).

More details on our Custom forecasts below. We look forward to working with you...Chris.

CUSTOM FORECASTS:
If you want a forecast by phone ($35 or 1 forecast credit), call 863-248-2702, after 10am AST/EDT

Text message (including satellite phones / Garmin Explorer / DeLorme InReach / Zoleo): send to chris@mwxc.com (or, if you must send to a phone number, use 941-915-7608). Be sure to ask a specific question, so we can be sure to provide the best answer in the constraints of SMS messaging. Cost is same as 2-day Custom email forecast $40 or 1 forecast credit).

When you want an email forecast, please email us the following in the morning and we will email your forecast later in the day (we can also schedule these in advance):

#1: your location / course / speed (and sail configuration if applicable)
#2: weather / sea conditions
#3: your PLAN, and anything I should know when creating your forecast, as well as any specific questions I should answer
#4: REQUEST that I email you one of the following forecasts:
a: detailed 5-day forecast ($70 or 2 forecast credits)
b. Detailed 2-day forecast ($40 or 1 forecast credit)
c. General 10-day Outlook ($40 or 1 forecast credit)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $299. ANY forecast credit can be used for ANY Custom forecast, so purchase either 10-pack of credits for $299).

TO PURCHASE:
If you do NOT have an account, please visit www.mwxc.com then click any orange "sign-up" link then complete and submit the form, or call 863-248-2702 anytime after 10am AST/EDT.

If you DO have an account, login to your account (if you do not remember your credentials follow the prompts to "Retrieve your login information"). Once logged in, either Renew your previous service or click the "SIGN-UP NOW FOR NEW SERVICES" link. Or call (863-248-2702) or email us and we'll be glad to process the order for you...Chris.

55. What is Departure Planning, and do I need it for my Custom forecast?
If you're on a tight schedule, and intend to depart on-or-about a certain date as long as it's not unsafe, then you probably do NOT need Departure Planning.

If your schedule is somewhat flexible and you want to depart when there's a nice opportunity, you should purchase your Custom forecast with Departure Planning. We'll communicate with you 3 days prior to intended departure, and continue monitoring weather and communicating with you for as long as it takes to find a suitable window to depart. When we agree on a good departure date/time, we will email Custom forecast and routing advice the day before departure (or the morning of departure if departure is later in the day).

Without Departure Planning, we'll communicate with you 3 days prior to intended departure, and if we can identify a a safe departure opportunity, then we'll email forecast the day before departure (we'll be somewhat flexible, and communicate again prior to sending forecast to ensure things still look safe).

56. First Mate light web app
We are launching a "light app" (called "First Mate") for your mobile phone, tablet and computer!

First Mate makes receiving forecasts easier and more reliable than email (no worries about SPAM filtering, white lists, etc.).

Access First Mate from a web browser, connect it to your login credentials at www.mwxc.com and bookmark it to your Home Screen / Desktop. Then, whenever you click the First Mate icon on your home screen (or desktop) it opens instantly (without needing to login again) and shows our latest forecasts, which are updated in near real time.

Try out First Mate here:

https://mwxc.com/first_mate/

Follow the steps fully detailed in this 6 minute video:

https://mwxc.com/First_Mate_Introduction.mp4

Please report any bugs / usability issues, comments, and suggestions to: chris@mwxc.com

57. Squalls along wind boundaries especially in the Tropics / sub-Tropics
(Updated Dec 12, 2023)
When wind speeds and directions are uniform, it may be reasonable to expect benign weather, with no big surprises.

However, especially in the moist Tropical and even sub-Tropical marine environment, changes in wind speeds and/or directions often force lifting of air, which supports squalls with significant wind.

Increasing predicted wind strength is cautionary. Faster-moving air molecules collide with slow-moving air molecules (we call this Wind Speed Convergence). This collision forces moist air to rise (it has nowhere else to go), which enhances condensation (releasing more heat into the rising air), and causes convective squalls.

Significant changes in wind direction where air molecules converge toward each other (for instance ENE wind N of you and ESE wind S of you) causes similar collisions of air molecules along the boundary where air molecules converge. We call this Wind Direction Convergence.

Conversely, when predicted wind speed decreases, the resulting Wind Speed Divergence typically causes Subsidence (tendency for air to sink), and this tends to inhibit squalls.

And when the changing direction of wind causes air molecules to diverge away from each other (for instance ESE wind N of you and ENE wind S of you), this also causes Subsidence, and is referred to as Wind Direction Divergence.

When you see predicted wind strength increasing, and/or changing wind direction causing air to converge, probe the forecast for precipitation.

Global wind models often fail to accurately predict wind in the resulting squalls (which can be very significant), so we have to make an educated guess about wind in the squalls.

Generally the heavier the precipitation, the stronger the wind will be. In some cases wind can be 2x as strong as models suggest, with embedded thunderstorms, and this wind may be very persistent over a large area along the Convergence.

58. How our services dovetail together for a comprehensive weather solution
Regional Daily Email forecasts provide the info you need to make your own good weather-based decisions every day (geography = E and W Caribbean, Bahamas, Florida, US E Coast), 6 days/week (not Sundays unless there is Tropical or other severe weather).

Webcasts/SSB (geography = worldwide) Nets allow you to participate in live, interactive sessions with us each morning and evening, 6 days/week (not Sundays unless there is Tropical or other severe weather) - via our Zoom Webcast or by SSB radio. If you're on the Zoom Webcasts, you type questions in the chat box and we answer verbally, while sharing our desktop, so you see the weather we're describing. We'll provide our opinion on a planned trip, departure timing, arrival timing, GulfStream, etc. as well as a verbal forecast just for your vessel / itinerary.

Custom forecasts by email, phone, text message (geography = worldwide, 365 days/yr) - when you want a detailed forecast and routing advice by email, phone, text message - just for your vessel / itinerary, including departure / arrival timing, forecast, routing advice, etc.

*.*

Regional Daily Email forecasts provide the info you need to make your own good weather-based decisions every day.
Tips for interpreting email forecasts here:

https://www.mwxc.com/faq.php#q13

*.*
Webcasts/SSB Nets allow you to participate in live, interactive sessions with us each morning and evening, 6 days/week (not Sundays) - either via our Zoom Webcast r by SSB. If you're on the Zoom Webcasts, you type questions in the chat box and we answer verbally, while sharing our desktop, so you see the weather we're describing. We'll provide our opinion on a planned trip, departure timing, arrival timing, GulfStream, etc. as well as a verbal forecast just for your vessel / itinerary.
Tips for participating in Webcasts here:

https://www.mwxc.com/faq.php#q1

Schedule for Webcasts/SSB Nets here:

https://www.mwxc.com/images/SSB_nets_grid.pdf

*.*
Custom forecasts by email, phone, text message (geography = worldwide) - when you want a detailed forecast and routing advice by email, phone, text message - just for your vessel / itinerary, including departure / arrival timing, forecast, routing advice, etc.
Tips for using Custom forecast Credits are below.

Thank you for your support!...Chris.

f you want a forecast by phone ($35 or 1 forecast credit), call 863-248-2702, after 10am AST/EDT (or WhatsApp, 941-915-7608).

We typically schedule initial weather assessment for 3 days prior to the earliest you expect to be ready to depart, so you can coordinate pre-departure activities. Once we agree on departure timing, we email detailed forecast and routing advice the day before departure (or the morning of departure if you're departing later in the day).

Departure Planning: If weather is not conducive for departure near your intended departure date, and pre-departure weather assessments and communications with you continue for more than a few days to find an acceptable departure opportunity, then your forecast needs Departure Planning ($25 or 1 Credit in addition to the detailed forecast).

To schedule a pre-departure forecast, please email to: chris@mwxc.com the following:

1. where you intend to depart from (and your present position, if different)
2. when you expect to be ready to depart
3. intended destination (final destination as well as at least your 1st planned stop, or if nonstop let us know that too).
4. anything else we should know about his Journey.

Each forecast will include our suggestion when to request your next forecast (this assessment is based on forecast uncertainty, the potential for high-impact weather, and timing of Decision Points along your journey, where you will need to make a weather-based decision.

We can format forecasts for sending via text messaging, but we can be more verbose / nuanced via regular email. Text message (including satellite phones / Garmin Explorer / InReach / Zoleo / BIVY Stick / Spot-X): send to chris@mwxc.com (or, if you must send to a phone number, use 941-915-7608). Be sure include details #1-#3 below, and ask specific questions, so we can be sure to provide the best answer in the constraints of SMS messaging.

If we expect you to need an additional forecast while underway, then our forecast should include our suggestion on when to request your next forecast. This is based on our confidence in the forecast, and the timing of any significant weather events, or weather-related decisions you will need to make.

When you want another email forecast, please send us the following in the early morning (preferably between 0600 utc to 1200 utc), and we will email your forecast during the day (we can also schedule these in advance):

#1: your location / course / speed (and sail configuration if applicable)
#2: weather / sea conditions
#3: your PLAN, and anything we should know when creating your forecast, as well as any specific questions we should answer
#4: REQUEST that I email you one of the following forecasts:

Credits can be used for email / text forecasts:
--5-day forecast with 10-day Outlook ($70 or 2 credits)
--5-day forecast with 10-day Outlook + Departure planning ($95 or 3 credits)
--2-day forecast ($40 or 1 credit)
--2-day forecast + Departure planning ($65 or 2 credits)
--General 10-day Outlook ($40 or 1 credit)
--phone-in forecast ($35 or 1 credit)
--video conference with recording ($70 or 2 credits)

(A "forecast credit" is 1 of your 10 prepaid forecasts if you purchased a 10-pack of forecasts for $299. Forecast credits expire 1 year from date of purchase).

59. Winter Trades from ABCs to Panama
Typically in winter, the ITCZ is S of the Caribbean, and fairly strong HI pressure systems migrate through the N Latitudes, driving a tight pressure gradient. These winds are typically from ENE-E in direction, due to orientation of HI pressure N of the Caribbean, and this makes N-bound travel particularly challenging.

The 20,000' Sierra Nevada mountains of Colombia cause W-ward propagating air over N Venezuela into NE Colombia to mechanically lift to 20,000', and particularly at night these winds come crashing down the W side of the mountain range, and surge off the Coast of Colombia, mainly from just E of SantaMarta to just NNE of Cartagena, causing a zone of very strong winds about 120mi across.

But even in winter there will be lulls, when either HI pressure N of the area is weak, or is suppressed well S-ward toward the Caribbean. These opportunities of more moderate weather are not frequent from mid-December into early February (though they do sometimes occur during this period), but we do typically see breaks in the strong Trades / seas the rest of the winter, and these breaks typically become more frequent as winter progresses thru spring.

I suggest you ask us to look at the long term weather pattern when you are contemplating moving on from Aruba, to see if, over the next couple weeks, the pattern is likely to support moderating conditions - if so, then you can make plans to depart - if not, then you may want to sit tight for a while, and check back with us later.

We can also schedule a Custom forecast with Departure Planning, and we'll monitor weather for you, so you know when there's an upcoming departure opportunity.

If moving toward Panama, one strategy that often works well is to plan to make 2 stops in Colombia: SantaMarta and PuertoVelero. In typical periods of relative moderation, by making these 2 stops, you can transit the windy part of Colombia during daytime, when winds / seas are lower.