WYorksWeather

Just comparing Meteociel's temperatures from today to yesterday at the same time: Most areas further north and west are cooler, but in terms of absolute maximum the south is getting a good start on heating up today. The key is whether thunderstorm development scuppers the last degree or two of heating in the afternoon. Theoretically there's no reason we can't reach 27-28C, but we'd need no sea breezes and no significant cloud development in the hottest areas before 2pm or 3pm.

UKV has backed off again at the last go - 26C the max on this morning's chart for this afternoon. Probably a nowcast at this stage.

Don I guess the SSTs probably prevented July 2023 from being below average, for example. Scorcher Especially when you consider that another spell like this one in two weeks time would by definition be hotter. So rather than temperatures maxing in the 24-26C range most days you'd have maybe 26-28C.

Don I think we still don't have enough of a sample size yet to know how rare below average 1961-1990 months are now. Up until recently I was thinking 10%, about one per year. If we don't get one by the end of this year though, I might have to reassess. Possibly you'd have to start saying 5%. It's definitely going to happen at some point - the middle of January and second half of April this year prove we can still get significantly below average spells of weather - we just need one to be sufficiently prolonged to enable a below average month and to not be counteracted by a strongly above average spell at another point in the month. Very difficult to predict when it might happen, though. It's just that the odds indicate that it pretty much must happen at some stage, since I can't really believe that we've moved so far in the last two years that e.g. a December 2022 repeat will never happen again. Even if you added a bit on to the anomaly it'd still be below average if the same synoptic had repeated last winter. As always, more data needed. If we go another full year or two with no below average months on 1961-1990 I'll have to revisit this question.

Derecho Looks like the EC control backs up my early look at the UKV. Key as always will be surface conditions with next week's low I think. Should have a good chance of staying above 14C to the two-third point (becoming only the second year to be above 14C at that point) and then as you say anything can happen. A benign end with a slow drop into the mid to high 13s, a sharper drop into the low 13s or upper 12s, and frankly sky-is-the-limit if we get one of the insane plumes that seem to just come out of nowhere these days. There are still ensembles throwing out mid to upper 20s beyond day 10 at the moment. As long as that is showing up it really feels like it'd be crazy to ignore the possibility. In terms of probability I'd put a 14s finish at maybe 50% going off the latest output and given the lack of any real cold signal. 13s and below gets 40%. 15s and above gets 10%. The 10% I think is a reasonable educated guess based on the number of ensemble members at the moment that go very warm / hot in the final week to ten days, which is what we'd need for that sort of finish.

Unfortunately had an early start this morning so couldn't stay up. Hoping for a chance tonight.

danm The question is whether we will beat it tomorrow? 27C is possible, but all depends on the timing of thunderstorm development - an hour or two earlier than forecast would be enough to scupper it, an hour or two later could allow a sneaky 28C, maybe.

damianslaw Tonight's UKV also rapidly dropping any chances of a drop. Not even sure that we'll see a drop at all up to Thursday. Here are maxima from Monday to Thursday: Just taking a glance at that, you'd expect maxima to average 20C for the CET, at the low end. Here are minima for the early hours of Tuesday through Thursday: Again, from this, minima probably also above average for the period, near 10C or so. If you combine with a 20C average maximum, that gives a CET average, possibly even on the slightly conservative side, of 15C. Of course surface conditions make a massive difference to this even at relatively short range, but I'd now expect that the CET will hold through the first half of next week looking at this, or maybe even rise slightly.

Having had a look at a couple of Hampshire weather stations (not knowing the area), your feel may well be right! It looks like most stations in Hampshire beat yesterday by around half a degree or so.

Locally or nationally? Nationally it definitely was with 25.9C at Herstmonceux being the highest I'm aware of. May be beaten tomorrow - UKV is sticking to 27C.

And the 15z UKV which is the penultimate run before tomorrow is sticking to 27C. More early-mid afternoon though - presumably thunderstorm development will limit any late climbs in the temperature. For CET watchers worth noting that the 27C spot is near Pershore. Beyond that, into Monday we see that despite tomorrow's thunderstorms the heat holds on in the east with 24C. By Tuesday the heat is much less widespread but still 23C in East Anglia. Warm all the way to Wednesday as well though - similar to Monday. A random 25C in NE Scotland as well, must be some crazy Foehn effect being predicted! And on and on we go - Thursday as well! What a change this is. Looking at the causes, it seems that UKV is developing far fewer showers than some of the other models over the next few days. It looks like eastern areas may escape frontal rainfall on Monday and after that there will be scattered showers and possibly thunderstorms. Here are the precip forecasts for mid-afternoon for the next 5 days: A fair few cloud breaks, not huge amounts of rain, and warm, locally very warm conditions. I really don't think even the early part of next week is going to be half as bad as it looked a few days ago.

In Absence of True Seasons I think what was remarkable about that period was how consistent it was in avoiding anything below average. You can see it on the CET chart below. Obviously some locations will have had a very different year to the CET but for many of us it's a decent proxy. From late January to mid April there were virtually no below average days at all on the 1961-1990 average. Admittedly this is the older average which is somewhat cooler, but it's still bonkers. Worth showing the min and max charts above as well - you can also see here that contrary to what a lot of people have been saying it hasn't been driven particularly by mild nights either. Almost equally mild by day and night. So far this year for the CET we have max anomalies of: 1.1, 4.1, 2.4, 1.6 and 2.5 (May to date) Mean anomalies of: 0.9, 4.0, 2.5, 1.7 and 2.3 (May to date) Min anomalies of: 0.7, 3.8, 2.6, 1.9 and 2.1 (May to date) In short, no months with a significant difference either way, not even half a degree difference in the max and min anomalies for any month so far.

Catbrainz For your location admittedly a very poor day for mid-May on Monday. Definitely not the case everywhere though. I think it will be a case of who dodges the showers and sees the most clear spells. Looks like eastern areas favoured on Monday but that may shift later on.

UKV still sticking to 27C tomorrow. Let's see what happens... Beyond that, we have 23C on Monday, 20C on Tuesday, and 21C on Wednesday. Between the showers it really shouldn't be too unpleasant. In terms of the cause, this UKV run doesn't really get rid of the higher than normal 850hPa temperatures even by Wednesday, away from the far south and west. Further update to come later on the 15z.

Alderc 2.0 The 03z downgraded the heat a bit, a bit of a bust really that as we have achieved 25C. Location also wrong. On the plus side it did call the cool weather in coastal areas e.g. Bridlington correctly. You can't win them all I guess. For tomorrow, after a wobble a day or two ago, UKV still going for 27C for the second time in a row.

Addicks Fan 1981 Here's the associated 850hPa pattern. Looks like an east-focused pattern at least initially. Hard to tell I suppose what might happen from there. However, worth noting that it was a warm outlier run, at least for now. Will be interesting to see whether or not any other runs latch on to this idea.

Another warm day here. Slight cooling breeze but with no edge to it so it actually feels quite nice. Around 21C here.

Just posted the following GFS perturbation on the model thread. Goes without saying this is a highly unlikely outcome at this stage, but given the discussion of heatwaves above I thought it was worth sharing here!

After temperatures dip back to average next week - just worth keeping an eye on the trend for a further lift up later on in the month. Some very warm or borderline hot model runs. Strictly just for fun, and for eye candy purposes only, here is P25 of the GFS 12z a couple of weeks from now. Goes without saying that this is not a forecast!

The people who write those comments under Met Office posts won't be inconvenienced by such trivial things as facts!

We now have the 15z UKV update, and overall it does look like a slight upgrade on temperatures both for this weekend and for early next week. Raw maxima of 25C tomorrow and 27C for Sunday. On to Monday, and though much less warm there is increasing confidence now that eastern areas will stay fairly warm. Rain unlikely to arrive until late evening or overnight. Raw max of 21C. Tuesday also looks better than it did on the UKV 03z, with a spot 20C. Wednesday is appearing on here for the first time, and again we have a spot 20C. A few people asking questions about the very poor temperatures for the time of year for Wales and SW / south-central England. On that, the main culprit seems to be below average 850hPa temperatures flirting with western areas, whilst the east stays average or possibly even somewhat above average. Here are the afternoon 850s from Saturday to Wednesday: Generally a greater risk of cold incursions in Wales and SW England than elsewhere, which might severely limit daytime temperatures if combined with cloud and rain. However, still time for these details to change. Summary I think overall this is an improvement compared to the previous update. A fair bit of rain around but if we're seeing 20C somewhere in the UK every day from Monday-Wednesday it can't be completely horrendous. I think a mixed early part of next week considering the UK as a whole, with the best of the weather in the east, is probably favoured. Some southern and western areas may have a very poor next few days though, unfortunately.

danm Cue conspiratorial comments about jets taking off on runways, thermometers on the tarmac, and scary red maps!

Summer8906 Yep - one of those periods that was far worse in the south. Up here this May so far gets about 8/10 rating from me through a combination of slightly lower expectations and also that the weather on many days has genuinely been better - we've had a lot more dry and very mild or warm-ish days than you have. Obviously next week will likely drop that rating some.

Summer8906 Hopefully not 2 followed by 3!

Scorcher Yep, another week like this one would do it easily.