Originally Posted by StuM
Are you talking about short term forecasting or longer term planning.
If the former, then as Conachair says, they all use the same models - so use whichever one you prefer visually.
If the latter, then there are two sources:
1. The traditional pilot charts based on historical records from ships collected over many years and available as downloadable PDFs here: Atlas of Pilot Charts - Covering the Major Oceans of the World
2. COGOW charts at Climatology of Global Ocean Winds - COGOW
which are composites of much more recent satellite
observations of wind speeds/directions (10 years 1999-2009).
As Stu points out, what is "best" (one of my least favorite words) all depends on intended use. Do you want a spot forecast
(specific location), wide area, short term, longer term historic trends...
My 2c and preferences:
WindGuru. I really like their graphic display. It packs a lot of info into one chart (average wind speed/direction, gusts, cloud cover, pressure, rain...all in one graphic).
Multiple tools. Like many, I download GRIBs. I also use NOAA RadioFax charts a lot. Be aware of the limitations of GRIBs (raw model output with no pro human review/revision, do not show fronts and other significant features, ...). Many mistakenly use them almost exclusively and do not compensate for their short comings.
Pilot Charts. I still use Pilot Charts, but as Stu posted there are more up to date tools/data becoming available.
And a step beyond your question:
Routing. I do my own weather routing and also weather route
for friends when Im ashore. I use all the above tools plus SailGRIB WR (which uses GRIB data for both winds and currents). Just finished routing for friends on a non-stop run from Florida
Their trip makes for a great example of a short coming of GRIBs. They downloaded GRIBs, looked at wide area systemic winds of about 15 knots and were all ready to go for it...what the basic GRIB view did not show them was large powerful cold front crossing the Gulf of Mexico
that would have crossed their route
in a few days. The surrounding systemic winds were not forecast to be much more that 20 knots, but....the conditions on the frontal boundary were forecast to be VERY unstable (CAPE index near 4,000 in some areas!). Such highly unstable air can result in extremely bad localized weather (which most forecast options won't show). I convinced them to delay their departure...the frontal crossing brought some really ugly weather over their location...they left on the front's trailing edge and made the entire run from FL to Guatemala
in easy favorable conditions...sure beats the butt kicking they would have gotten on their original GRIB only based plans.