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From: rpw3@fortune.UUCP
Newsgroups: net.ai
Subject: Re: AI and Weather Forecasting - (nf)
Message-ID: <2249@fortune.UUCP>
Date: Wed, 11-Jan-84 19:07:00 EST
Article-I.D.: fortune.2249
Posted: Wed Jan 11 19:07:00 1984
Date-Received: Fri, 13-Jan-84 04:41:38 EST
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Organization: Fortune Systems, Redwood City, CA
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#R:sri-arpa:-1524700:fortune:21500007:000:1342
fortune!rpw3    Jan 11 15:35:00 1984

As far as the desirability to use AI on the weather, it seems a bit
out of place, when there is rumoured to be a fairly straightforward
(if INCREDIBLY cpu-hungry) thermodynamic relaxation calculation that
gives very good results for 24 hr prediction. It uses as input the
various temperature, wind, and pressure readings from all of the U.S.
weather stations, including the ones cleverly hidden away aboard most
domestic DC-10's and L-1011's. Starting with those values as boundary
conditions, an iterative relaxation is done to fill in the cells of
the continental atmospheric model.

The joke is of course (no joke!), it takes 26 hrs to run on a Illiac IV
(somebody from Ames or NOAS or somewhere correct me, please). The accuracy
goes up as the cell size in the model goes down, but the runtime goes up as
the cube! So you can look out the window, wait 2 hours, and say, "Yup,
the model was right."

My cynical prediction is that either (1) by the time we develop an
AI system that does as well, the deterministic systems will have
obsoleted it, or more likely (2) by the time we get an AI model with
the same accuracy, it will take 72 hours to run a 24 hour forecast!

Rob Warnock

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