Djdazzle

"Big impacts on health": yet there's nothing on the BBC website. What is wrong with this country? People need to be warned now - most people I've spoken to just think it's going to be a hot couple of days.

But even that isn't quick enough to prevent 40C on Tuesday.

As has been mentioned, even the ECM (the most progressive model with clearing the heat away on Tuesday) would lead to a 40C+ day. I'd be assuming that bets will be off today with regards to beating the record - it's pretty much certain that it will go on Monday and Tuesday.

That's the highest temperature from 18z to 00z. Doesn't mean it'll be 38C at midnight.

40C is more than bearable if you can sit in a shady place, have lots of fluids and don't need to exert yourself physically. The above is not the case for the majority though.

24 hours notice would be insufficient. People need to start to take this seriously now. I'd expect schools to be closed.

Never seen a temperature of 39C on these apps.

Brave call just because of ECM! I think it's at least 50:50 that the record goes on Monday. And then again on Tuesday,

The morning temperatures modelled for Tuesday are crazy. It reminds me a bit of July 1st 2015 when it was 34C by 11am. Looks even more extreme than that.

The shorter range, hi-res models now starting to come into range. As was mentioned earlier, there are a couple of 40C plots on the UKV. ARPEGE etc will be interesting. @CreweCold has a point in that warning needs to be issued.

Insane minima.

Yes it’s an epic failure from the models (and pros) for today. I’ll reserve judgement on tomorrow!

I tried to make a similar point earlier. The models have been pretty off the mark for today’s conditions at very short range. So I still think anything is possible for Sunday - Tuesday. Write off 40C at your peril! UKV had temps of 29 today, and it’s likely to be 32.

Yes agreed about the high cloud - but that in itself wouldn't prevent some sunshine. It's been more like mid-level cloud.

Yes, I saw those. But Meto forecast even this morning went for sunny spells in the south. Doubt it will be that low. Just the usual inter-run variation.

Don't expect detail for next Sunday and Monday yet. The models were wrong about today only yesterday. Wasn't meant to be cloudy today.

The 6z has actually gone back more to the high temps.

Agreed. Small adjustments in this setup can make big differences down the line. What I would like to see expunged is the trend to bring in an easterly flow. The 6z seems to have bucked that.

40.6C at one of the London stations (Monday 18th July).

Don't forget though - the BBC will be using old data for their forecasts. This time yesterday, the record looked more likely to be broken. However, if the trend on the GFS 6z continues on the 12z runs, we may well be back in business.

I think we need to see the 12z runs first.

I think the GFS 6z shows that we shouldn't write off chances of breaking records just yet. We have seen this before. In August 2003, the peak of the heat was forecast to be gone before 9th / 10th August. However, as it approached, the models trended hotter, which is what actually transpired.

In answer to a previous post, Paris is not always 2-3 C warmer than London. Today is a case in point, with London actually warmer than Paris.

The usual under-playing of temperatures. They are always below what actually transpites.

16 straight days above 21C is hardly noteworthy in July in southern England!