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Daily Weather Charts 3 Day - 2020 Update

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Daily Weather Charts 3 Day - 2020 Update

Postby Roy Dade » Thu Dec 19, 2019 10:58 am

Dear All

I put together the 3 day forecast page which Geoff posted and feel it’s time for a refresh.

What I’d like to do is add some RASP graphical forecasts for today covering wind speed, direction, cumulus potential, cloudbase etc with short notes below.

I’m open to suggestions on any of the rest of it, what people like or don’t. I plan to do any changes over the Xmas break so comments here please by the 24th.


Roy Dade
Posts: 218
Joined: Sun May 05, 2013 6:00 pm

Re: Daily Weather Charts 3 Day - 2020 Update

Postby Dave Thomas » Fri Dec 20, 2019 10:36 am

With regard to our continuing weekly commentary forecast advice on the forum. An article by Jean Oberson taking information from Dr Jack about the complexities of the various modelling tools and why RASP is sometimes wrong, but other times more accurate than others, includes these statements.
Weather model do not predict the real weather !

They actually predict a schematic and coarsely simplified image of the atmosphere and do not forecast the real micro-infinitesimal (in fact probably molecular scale) atmosphere. So there is two separate worlds : the real molecular one and the finite one whose resolution is defined by its grid whose spaces between grid points are much larger than molecular scale.

Human evaluation of RASP results together with other information should produce a superior forecast - but of course that depends on the correctness of the "added value" that the human provides. One way that "human intelligence" comes into play is through knowledge of model strengths and weakness * particularly by recognizing when the latter are making a model forecast unlikely.

We're not always right but I hope you think we do often add that extra value, in interpreting the forecasts in relation to the micro-meteorology of our sites from years of experience and what and where might work on a partticular day.
Dave Thomas
Posts: 1767
Joined: Thu May 02, 2013 12:45 pm

Re: Daily Weather Charts 3 Day - 2020 Update

Postby Roy Dade » Fri Dec 20, 2019 1:45 pm

Hi Dave

I think the weekly forecasts are invaluable as the various models have got their limitations as we’ve discussed. The RASP Star Rating is a good example of one of those things that can be quite a bit out sometimes and should only be used as a trigger to look a bit deeper.
Roy Dade
Posts: 218
Joined: Sun May 05, 2013 6:00 pm

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