kold weather

Jeez got to think Heathrow us there as well. Remember 36.8c gets a top 5 all time temperature. It's going to fall and be the 3rd top 5 day ever... Mad...

34.5c from the sounds of things, so was a rounded up. That was 30 mins ago now so we may now be well into the legitimate 35c range. Top 5 well within range and whilst the cloud is coming, it's not coming quick enough to stop a 37c now it seems. Well done to the met office for sticking with it even when the models this morning took an edge of the maxes incorrectly it appears.

Im pretty much dead upstream on this flow and the cloud cover is starting to arrive from the SW but I think Heathrow has another 2hrs before the cloud covers the sun. Anyway, Heathrow Already IS at 35c! Record attempt may well be on after all IF the cloud stats clear for another 2hra. May just miss it BUT few doubts we will be getting in the top 5 now (just 1-2c shy with peak heating still well over an hour ago.)

Worth noting this is actually 2c AHEAD of the 37c forecast from the met office at the same time...

I'm currently in Chichester which is probably 90 mins upstream from W.London. Just the first signs of mid level cloud from the channel convection but skies mainly clear still. Doesn't look all that thick however at least on the leading front so some of that may well decay. Snowy L - yeah GFS is trash with these setups! The plumes western edge is more active than forecast though. Also Heathrow upto 31.4c at midday with several others at 31c. Should comfortably be through 33 sooner than later. I'd guess cloud cover could become an issue by 4-5pm for W.London but just a guess. By then should be around 36-37c. Edit - Heathrow at 33c now!

What should happen is the front edge will get eroded as it comes on land. It won't disappear however as it's from the frontal boundary, but it may not be all that significant. Still, it probably will put a lid on things eventually and we see the odd storm spark off from it overnight. Snowy - not really, the models Never went for that sort of heat countrywide,, it was always going to be mainly a SE event due to that frontal boundary. Heathrow at 31.4c at 12pm, so rough 2c puts us to 35c by 2pm.

A fair chance we will be closer to 40 than 33 ?️ No, I'm not saying 40 of course, but 36-37 is really very doable as we are continuing to warm up (ECM and Arprge increase thickness right through to 18z!) And so a late peak seems probable IF cloud cover isn't an issue. Also, wind subtly shifts in the afternoon and we pull in aid even more directly from France.

that's only the case recently because usually a cold front started spilling cloud into the areas that are likely to get the highest temperature. Between 3 and 4.30 normally is peak temperature of the day typically and unless we get a surprise amount of convective cloud come over the usual hotspots I would guess that will also be the case today. Cou IMO we are gunning for something in the 36s, maybe low 37.

again remember people we are advecting hot air right through the day today this is not a typical heatwave when it hot air advecation ends around midday due to encroach and cold fronts as we normally see. so typical values expected from the temperature from this time of day are going to be too low compared to normal because of this hot advection that's happening. Top 5 requires 36.8c. basin background conditions as long as convection stays clear this should be doable but it might be close.

Broadly 1-2c lower. Today will give a good indication of the models grasp of the actual heat and will show whether the models backed off too much. Still very hot to be fair as well. Steve, given we are still accepting warm air in its entirely possible we carry on at near 2c an hour through to 3.30-4pm before things level off.

And it needs to be remembered that unlike normal heatwaves the upper heat is increasing during the afternoon, whereas with normal extreme temps it comes as the cold front comes in and decreases uppers during the afternoon. In theory we can squeeze more out of the afternoon then in normal one day heat events due to how this is evolving. Whether enough to make up the difference I have big doubts but it will get higher than you'd typically expect given current temperatures as long as cloud stats clear.

I'd be surprised if we were to get a record today. Even putting the cloud aside we are now a little behind the pace of Aug 03 and last week for example. The slight thing on todays side is that the heat is actually still coming up from France throughout the day, usually in these set-ups the winds start to shift around 3-4pm as the front comes through. That isn't really happening in the traditional way today as SB said above. However, very possible that if the mid level cloud steers clear that we could end up in the top 5 hottest days ever (36.8c will do, IMO that is there for the taking) and that would mean 3 out of the top 5 ever hottest days have come in a 13 month period...crazy!

Great looking run there Mr.Frost! As said before, as the heatwave goes on the more unstable things get, especially from Monday onwards, good chance of evening storms kicking off in many different parts of the country and rumbling away into the overnight hours. Should be a pretty interesting spell coming up now!

Going to be a touch and go call on whether that convective mass over SW develops further and spreads its cloud canopy. That will probably determine to a large extent exactly how extreme we go in terms of heat. We are a little down on where we were on Friday, but the difference this time is the upper heat isn't decreasing at all over the course of the day, if anything it slightly increases which means in a clear situation we'd probably keep the heat up longer than you'd expect which would make the difference up of a cooler start. However that really all does rest on the skies being clear enough to take full advantage of that.

I suspect it probably will, its matching 00z AROME pretty much perfectly at the moment so no reason to think that the AROME forecast isn't right. This run limits temperatures to around 34-35c for most (maybe a touch higher for somewhere like Heathrow) due to the convective over spill coming into the region from 1-2pm onwards. As for what happens tomorrow, hard to say at the moment. In theory the conditions aloft should be even more favorable for heat given a much higher base to start with, however how much convection is still lingering around/forms is going to make tomorrow something of a nowcast. Maxes from 33-38c seem possible.

If your just looking at the chance of record breaking temperatures, the cells to the SW make that much more difficult. Not impossible by any means, but harder for sure. Its not much, but when going for the truly exceptional in somewhere like Heathrow, that does make a difference to the odds.

I think we as a region will be very unlucky not to see some thunderstorm activity as the heatwave rolls on, the flow looks pretty unstable to me and there is some decent enough CAPE to work with for any storm that does kick off to get fairly strong, especially past Sunday. Just worth noting the temperatures across the region are about 1c down on where they were last week, so increasingly unlikely we get as hot as last week today, and that is ignoring the convection currently developing over the SW and moving NE that may well spill mid level cloud into the western part of the region by 2pm. Still every chance of reaching 35-36c today though, which by any normal times standards is madness (we've been spoiled in the last 13 months!)

Much is going to depend on how discrete any thunderstorm activity tomorrow becomes. Arome certainly going for a very active outlook tomorrow compared to other models over the SE, looking at the met office website they also show some shower activity although not as much. My guess is somewhere in the middle. The flow is fairly unstable so I do expect some to kick off, but I feel the AROME is rather overdoing it for tomorrow (it can be overagressive in these set-ups) and anywhere that stays away from convection is probably going to have a fair shout at 35c tomorrow, if a hotspot stays clear, then those 36-37c ranges very much are do able again.

Given there is a front straddling along on the country for fair parts of this upcoming week, I'd be amazed if it doesn't get very stormy by Monday/Tuesday. AROME though already has some decent convection developing today on the southern end of the front travelling NE. You can see it on the radar moving towards Dorset. It then develops quite alot of showers tomorrow into the SE quarter of the country (which limits the most ridiculous heat). Other models are less keen but even they are widely breaking out storms across many parts of the country broadly aligned with the location of the front that straddles the country, and this slowly edges eastwards looking at the 00z runs over Mon-Weds. Probably got 3 days of really high potential for storms, and then the upcoming 3 days (Fri-Sun) probably has chances but just not quite as high. Going to be feeling real tropical as well in the SE...bring on the warm rain!

Several high resolution models have some shower activity breaking out over E.A *tonight* with there being a decent chance of something kicking off tomorrow (which is why some of those models now have a much lower forecast for tomorrow down to only 32-34c maxes). Worth watching that band in the SW, it looks reasonably active and don't be surprised if mid level cloud from it spills into our region by 2-3pm which may just prevent the very highest temperatures occurring that are forecast. The flow does look increasingly less stable, the AROME for example breaks ut quite a few showers tomorrow, which is far from impossible if the front remains straddled close to our area as oer forecast (as usual, the closer to the coast you are, the better the chances of keeping dry and hot, which is why the models are now focusing any 34c+ heat south of London).

Yes the AROME shows a line of convection slowly drifting NE, it looks a litlte more active on the fronts southern tail than was advertised yesterday which leads to a stronger chance of some convective action making it towards the SE by the close of plsy today, and indeed several models are kicking off showers even over the SE overnight. How high Saturday goes probably largely depends on how much convective overhang there is and whether any more cells break out. Mon-Weds now looking increasingly stormy and basically tropical in nature, with 30-33c in the SE and high chance of daily thunderstorms for just about all. Very impressive to see and going to be an amazing, if maybe unbearable at times and for some, period of time coming up.

Much like the other high resolution models, this too has also just shifted downwards a peg or two from the 35-36c range seen yesterday towards 34 with a localized 35c. Still exceptionally hot though across much of the SE, not often you get quite such a widespread area of 33-34c for several days forecast.

Yes if it comes off that would be insane! That being said the models have slighly edged downwards overnight on the heat, I suspect partly because they are looking increasingly convective from Sunday onwards as it comes closer towards the timeframe. I still suspect somewhere is going to reach 32c every day until maybe Thursday as this point which would be a very impressive run of such high temperatures. However 5 days going 35C IMO is totally at the behest of there not being as much convection around as currently expected, which given the fairly low pressure and increasingly unstable airmass, looks a touch unlikely to me.

Well we will soon be off to the races with the heating temperatures. Looking very hot today. As I said on the models thread some of the high resolution models have a touch backed off from the record breaking type heat today and tomorrow, though all are in agreement of 34C+ being recorded so even if they are right, its still very hot indeed, and you'd expect the usual hotspots to be 1-2c up on that figure as well. Current temperatures broadly match what was on the 00z runs of those models.

Quite unstable on the ECM for Tuesday and Wednesday (and some areas Monday). Looking very tropical in nature with high heat still (the convection does limit maxes somewhat though still hot, with the usual under-estimation your easily into the 30s every day) and probably decent risk of thunderstorms, especially over places like the Midlands where the cap will be that bit weaker already due to being on the edge of the plume. Models again also suggest the development of thermal lows in our neck of the woods, again something typically seen somewhat further south in latitude! PS- also just worth mentioning that several of the high resolution models have somewhat backed off the extreme heat today. May not mean much as these models have been wrong at this range before, but they are broadly coming in 1-2c cooler than yesterdays runs for both today and tomorrow. Something to note.