In the last post I explained how to receive text forecasts while offshore. Now I want to share one of my favourite forecasts, that I suspect very few people bother to get:
The forecast discussion in which the duty forecaster explains in very frank and informal terms how he or she arrived at the forecast, and most important of all, their level of confidence in said forecast and their thoughts on what other scenarios might develop.
Particularly if there is a strong storm or a hurricane brewing, I always get the forecast discussion to help me evaluate the likelihood that the storm will behave differently than the current forecast is predicting.
A Real World Example
For example, the forecast discussion warned us three days ahead of time that the fast forming Halloween Storm of 2011 was a very difficult one to accurately forecast and that it might come closer to Block Island, where we were anchored, and be more intense than the forecast and GRIBs at the time were predicting. Of course that is exactly what happened, but thanks to the discussion we knew that that was at least a possibility well ahead of time.
(The excellent US weather office always provides a discussion, I’m not sure about other offices. Anyone know of others? Please leave a comment.)
Further Reading
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Example forecast discussion.
Alex Kerney January 19, 2012 at 3:44 pm
Plus they can often be pretty funny. Especially as the NHC guys start to go nuts with either a really quiet spell or a really busy one.
“FRANKLIN…THE STORM…NOT THE FORECASTER…HAS BECOME A LITTLE BETTER ORGANIZED OVERNIGHT.”
“THERE ARE NO CLEAR REASONS…AND I AM NOT GOING TO MAKE ONE UP…TO EXPLAIN THE RECENT STRENGTHENING OF EPSILON AND I AM JUST DESCRIBING THE FACTS. HOWEVER…I STILL HAVE TO MAKE AN INTENSITY FORECAST AND THE BEST BET AT THIS TIME IS TO PREDICT WEAKENING DUE TO COLD WATER…HIGH SHEAR AND DRY AIR.”
“ALTHOUGH THE ATMOSPHERE SEEMS TO WANT TO DEVELOP TROPICAL STORMS AD NAUSEAM…THE CALENDAR WILL SHORTLY PUT AN END TO THE USE OF THE GREEK ALPHABET TO NAME THEM.”
If your in a mountainous area the local avalanche forecasters will often also have good weather forecast discussions too, though obviously not for sailing (unless your on the Dillon Reservoir).
John January 21, 2012 at 2:29 pm
Hi Alex,
Great quotes, they really make the point, thank you very much. Where did you find them?
Alex Kerney January 21, 2012 at 2:31 pm
From the comments here: http://blog.xkcd.com/2011/08/29/for-the-small-handful-of-hurricane-geeks-out-there/
Carolyn Shearlock January 21, 2012 at 12:03 am
Years ago I read a book about the Windjammer that was lost in Mitch and one of the things that became clear was that they had NOT followed the discussions and therefore did NOT know that the forecasters had very little confidence in the projected path of the storm . . .
I’ve always watched the discussions to get a feel for the prediction . . . and highly recommend it to everyone!
John January 21, 2012 at 2:27 pm
Thanks, Carolyn, a very sobering story.