On Thursday, 6 July 2017 09:53:08 UTC+1, wrote:

And this isn't the first time. If all their expertise and their very
expensive supercomputer can't even get a forecast right 12 hours ahead then
whats the point of them?

They're trying to forecast the popping up of convective cells using mathematics. Often the wet and windy weather we get in the UK that is forecast hasn't even formed before it's forecast. Using entirely mathematical equations. It's a miracle they get close - and for that we should be thankful.

Out of interest, do you come on here to praise weather forecasters when they get it right?

Richard