Mark Smithy

BBC / Meteo have general temps peaking at 38C today and 38-39C tomorrow but with this on top:

We are not a "laughing stock". I'm glad you have temps of 31/32 which, as you say, is bearable. 40C isn't, which is the likely temp in places tomorrow. I've lived through those temps and there's a huge difference from 31C. 40C is dangerous and will cause a significant number of excess deaths. The last, lesser, heatwave caused 1600 excess deaths. So don't be a nitwit.

So glad you have a nurse with you, albeit also suffering. I dread getting it at the moment being on my own. Stay safe.

It's quite intriguing to me to see the Meteo Group / BBC still suggesting 40C today. In their forecast they mentioned potentially 41C or 42C tomorrow at somewhere like Cambridge. We had a brief discussion yesterday about which models they use for this and eventually settled on a composite but it still intrigues me given that GFS has backed away from 40C today.

Yep but the nuance of that is because the plume was slightly slower to arrive so what you don't get today you get more fully at peak tomorrow, and still some residual on Wednesday which previously wasn't there at all. GFS has been the closest to this all the way so it's a bit much to take a swipe at it now, no? The steepness of the temperature elevation has astonished me: from relatively cool this morning to 30C by 10.30/11.00 is incredible. Again, GFS did call that right.

XCweather.co.uk is a very simple quick view one Personally though I prefer www.weatheronline.co.uk You can get a whole load of details and seems to be very accurate. Click on temps and you can choose table and warm-cold if you want to see the hottest place in the uk, or map / large map if you want to get an overview, or just click on an individual station. Great place for this kind of data.

You can clearly see the band of cloud across the southern strip of southern Britain on the latest NW satellite: To state the obvious, places which had some overnight cloud cover will generally be starting with higher temps whilst those with clear skies have seen a much fresher start: single figures in parts of Wales. I don't know if this is going to affect the temps today but GFS has definitely dropped a notch or two for today, whilst if anything ramping them up for tomorrow showing 42C - with even 35C now showing in East Anglia on Wednesday. I guess we are about to find out just how steeply temps will or won't rise. It's difficult to see a temp record going today but who knows?

I apologise if I was being a bit unfair to Kold Weather. I had thought the GFS was overstating it and went in with an open mind but it soon seemed that criticism of the GFS's modelling was the thing wasn't entirely fair. Okay, maybe it errs a little bit on the warm side but it hasn't been that far out and was actually under for the UK today. That's all. It's the ECM which has been really out but maybe tomorrow and Tuesday it will get it right? After all, we're talking record-breaking temperatures. Generally I've been pretty impressed with the GFS's modelling on this heatwave.

Something I discovered today. I have a fan in the bathroom set on the lightbulb switch, so I unscrewed the lightbulb and left the fan running. Made a MASSIVE difference to the temperature in there. I was really surprised. Just a little tip! Oh, and if you're wondering how to see: a torch or the shaver light bulb.

Seemed pretty much spot on to me for the key plume area of the SW: They went for 40 and one of two 41C's and some 40 and 41C's is what we saw. And a scattering below that. Pretty impressive accuracy I reckon.

GFS nailed SW France where the plume was sitting. I didn't check closely the rest of the country.

The fact that the Met Office just confirmed that Hawarden reached 33C today means I think that 39C is pretty much certain tomorrow, which is an extraordinary thing to write. The GFS temps have been spot on. ECM very low.

So sorry to hear this. Keep cool if you can with regular cool showers etc. and paracetamol. Central parts of where? Hawarden was 32.2C.

32.2C at Hawarden. The GFS has had today's maxima spot on. If anything 1C low. ECM is really low. So tomorrow? 39C? Maybe? As for Tuesday well ... you've all seen and commented and as Tamara says, it's utterly insane. We should all heed her remarks.

Okay so looking to our south and the source of the UK's plume heat, the GFS look if anything to be under with their maxima for SW France (not so sure about further north today). 40C has already been reached there and they 'only' forecast a maximum of 41C. There are 4 more+ hours for maxima to be reached. Remember it's still only 13.15 zulu time. So Tamara's point from Portugal, that the models have underestimated the maxima in this plume may well pertain for the UK Monday and Tuesday

Oh merely to show that the GFS is going to have their France maxima spot on for today. As those are the temps now then by the time 17h00 zulu is reached (19h00 French local) then if anything GFS will have under-estimated them not the other way around. Here as a reminder are their model forecast maxima for today. I see nothing in the current evidence to suggest these won't be reached.

Yep which means the GFS has it exactly right. And as for the zulu time issue. It's currently 12.30 zulu time, so GFS is going to be even more correct with its maxima in France today.

So we have already hit 30C today at 13h00. GFS temps win again over ECM! Interestingly the current hot spot in the UK is at RM Chivenor which leads back to the discussion earlier about the models showing 39C for the same area tomorrow. Foehn effect with the long draw from the sea up and over Dartmoor / Exmoor? I think right now you might not bet against a very high temp there tomorrow.

So one chart is of France and the other is of the UK? Not quite sure what has got into a couple of people on here with this. I've posted a chart of actual 13h30 temps now in France and the GFS 17h00 max for today and can see no basis at this stage for a claim that the GFS maxima are 'over the top'

And I don't see evidence that it has done so for France today either. Looks to me like it's going to be spot on. If anything, a little under.

That's not for 13h00 though, is it? You clipped it without any time reference, nor indeed any link to which site. I've just posted up the current temps from meteociel.fr vs GFS 17h00 temps and I can't see any basis at the moment for Kold Weather's wild claims. I may prove wrong but at Tamara noted, if anything the models have underestimated the European heat in practice.

For example, these are the temps now and these are the temps forecast by the GFS for 17h00. I can't see much basis at the moment for suggesting the GFS is going to be 'over the top'?

You keep repeating this without providing any verifiable evidence. If you're going to make assertions of this kind, at least back it up with hard, proper, verified evidence i.e. model output charts vs actual verified weather station reports. Not a casual glance at a couple of distant charts, picking and choosing a time of day. I'm not saying your evangelical zeal on this is misplaced but you're not helping your cause.

Link? It's going to be badly out.

Wow. So with reference to KW's analysis of the ECM vs GFS, it's actually the ECM which is wildly out.