SailNet is a forum community dedicated to Sailing enthusiasts. Come join the discussion about sailing, modifications, classifieds, troubleshooting, repairs, reviews, maintenance, and more!
Okay, all you old salts know exactly what I'm talking about: charts that feature the little "musical-note" symbols, which tell you how much wind is typical, from what direction, at what time of year ...
What do you call these "maps"? Can they be found online? I'll need to learn to use them to prepare for an upcoming circumnavigation in my Catalina 22. :svoilier:
(YES I'm kidding about that last ... but I do want to learn about them ... thanks!)
If you want to use the old antique type weathers charts our Government still uses them go to NOAA.gov/weather. but a lot of sailors today use web sites like Sailflow.com much easier to use and read.
You could use any number of apps for PC, iphone, Android, etc. that has the wind data info you seek... this is just one of many but will give you clues to use. I would get Chapman Piloting or some other book that has an extensive section on reading weather maps.
Okay, all you old salts know exactly what I'm talking about: charts that feature the little "musical-note" symbols, which tell you how much wind is typical, from what direction, at what time of year ...
What do you call these "maps"? Can they be found online? I'll need to learn to use them to prepare for an upcoming circumnavigation in my Catalina 22. :svoilier:
(YES I'm kidding about that last ... but I do want to learn about them ... thanks!)
They are known as Pilot Charts, published by month. They can be found at (click on) NGA Atlas of Pilot Charts. .
Select the region and time of year you're interested in. The "wind roses" show the direction of winds by percentages and the "feathers" on the arrows, their average force.
Look at passageweather.com and pick out the map relevant to your area of operation. The wind maps can be animated or advanced frame by frame, but be aware that the information is for GMT so you have to convert that to your regional time zone. They basically take the publicly available data from NOAA and give you hour to hour weather charts. It is a good tool not only for planning your trip but also studying the weather and typical wind patterns during the day for someplace you are trying to learn about.
Unasked for trivia.... The "Pilot Charts" have been compiled from ships logs starting back during the days of the British Admirality thru the present. Several hundred years of observations of wind and current in a given location on a given date are used to compile the info shown on the charts....
Okay, all you old salts know exactly what I'm talking about: charts that feature the little "musical-note" symbols, which tell you how much wind is typical, from what direction, at what time of year ...
As others have noted they are called pilot charts. As Cap-Couillon notes they are based on hundreds of years of data. It is pretty clear that there have been changes in that time. Jimmy Cornell has an updated global set of pilot charts based only on the last 70 years or so and dominated by satellite data collection. Highly recommended.
Except that Passageweather is based entirely on GRIBs - the direct output of a single computer model untouched by human hands. Artifacts we care about like cold fronts are not reflected.
Synoptic charts that are developed by real live meteorologists based on multiple models, weather balloon reporting, overhead visible and IR and radar imagery, and ship reporting are better.
There is a bit of confusion in this discussion between weather and climate. Pilot charts show climate patterns - long term averages of winds and other conditions. On the other hand GRIBs, Passageweather, and the like are weather maps. They show current and predicted (for a few days) wind conditions. These might be very different than the long-term averages shown on pilot charts. Both of these are very useful but they fundamentally different purposes.
You are correct, sir. Climate data is all I'm interested in, not weather, as far as my original question is concerned. For long-term planning. Which way does the wind blow in Port-aux-Francais in February, and how strong is it ... that sort of thing.
Windyty.com is fun to look at and scroll around on . . .
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
SailNet Community
1.7M posts
173.9K members
Since 1990
A forum community dedicated to Sailing, boating, cruising, racing & chartering. Come join the discussion about sailing, destinations, maintenance, repairs, navigation, electronics, classifieds and more