kold weather

reef Sounds like our version of 2021 down here in the SE, bar the first 7-10 days of June and a 5 day period in July it was a utterly dreadful summer down here, made even worse that statistically its actually pretty good for much of the rest of the country, so causing considerable envy. I still contend that locally the spell between mid June 21 and just before the July heatwave was amongst one of the worst I've ever had in summer, even comparing to summers like 07 and 12. Kind of an inverse to the usual, I can't imagine we see that kind of pattern all that often. EDIT - just looked up the local station for June-July 21. We had a 4 week period which had just 58hrs. For context, that would be a slightly below average *February* total locally....

You only have to look at how rapidly things shift in a continental airflow to know of course things can shift pretty drastically. It's just far more rare here as we are surrounded by water which will always nerf extremes.

danm that would personally be my reading of things. the only real way to know 100% would be to look at rain days and what the numbers look like. You could convicably have less rain days but higher average. Of course in recent years with sluggish broad patterns such setups are producing exceptional spells on a fairly regular basis

danm i think what is making it feel wetter is in the last few years in particular we've got into real ruts, where we can go 45-60 days with exceptional rainfall followed by almost the same tine without any. It does also need to be noted that on the ewp metric there is a clear sign of more extremes. With about 260 years in the bank you'd expect 2000-2023 to have maybe 2 years in the top 20 wettest years. This period already has 6. 2019 literally sits at 21 so it is also in the top 10%. 2008 would also make the cut. I think our distribution of wet/dry years may not be changing biut I do think on a very long term average we are getting more extreme wet years.

Interestingly there is one trend that does keep popping up into El Nino to La Nina years and that is got a spark geographic divide in August. The south/SE typical has the better of the weather, N/W often cooler and wetter as well. 2010 is ironically the only one to buck that trend somewhat in August.

March 2013 was the 14th coldest ever recorded. Its not quite in the same league relative to its position as December 10, but it was a pretty impressive month nonetheless, especially when knowing the 2nd half was the colder part of the month. April 21 is a more modern version of a coldish month, it's equivalent winter CET would be about 1-1.5c which would be regarded as a cold month even in the past, nowadays would probably be quite severe if combined with snowfall.

Summer8906 interestingly it was a nice afternoon here, though the morning was not the best. I had a similar look to that photo, but maybe a little more high cloud.

B87 really does show how dreadful 2021 was down here. Id guess something like 100-125hrs came within the first 10 days of June which were actually pretty decent. So we probably only managed 350hrs for the whole rest of summer, which would be pretty meh total even for spring!

CryoraptorA303 I wonder whether we need to adjust for temperature inflation to get a better steer? Given the Atlantic is running way beyond even last years record (in itself a huge anomaly) I think perhaps looking at Febs/Mar combos a good 1c cooler may yield something to draw upon? Have to say the summers where we will a fast transition to La Nina have tended to be on the poorer side of things, SB did a list on another thread and it was not a great list overall.

raz.org.rain there are always going to be other factors. With that being said historically a strongish nino that too rapudly goes La Ninw tend to be on the poor side. If we get a slower transition through summer then we may get away with it. However we haven't got a huge number of years to compare with and you do need to take each year at its own merit.

One look at the CET tells the story. We've been more or less around the 7c mark on that metric for the last four months, bar a spell in Mid Jan. There really has been an amazing lack if variation recently. I really do think it's fair to say we've just had a very long extended autumn this year. Still patterns don't go on forever and they usually abruptly shift for better or worse so gotta keep an open mind. Last spring for example, terrible March, totally meh April, may started off very wet but pattern shifted around the 10th and we ended up having a pretty sustained and decent spell. Shame it fell apart again in July.

MattStoke thing is if it timed later the day before would have been cooler, the night mins cooler due to the lower daytime temperature from the day before which would probably mean that whilst the warming the next day would have been higher itd start from a lower base which probably levels out at the surface. there is a theoretical max that an airmass can support regardless of timings afterall. How close we were to that is up for debate.

Yeah can only agree with the others, most countries yhe other side of the channel only manage somewhere between 40-42c. Paris is nearly there but still a hair short, and all those places don't have a modest moderating impact the channel has. I can probably make a theoretical claim to it making 43c locally in the UK, but it'd need such perfection at the moment its more or less impossible (probably 1 on a 1000 year type event at the moment I'd guess?)

I think we can already basically rule out a below 61-90 month now. Itd probably require the last 10 days to pull off a 2013 repeat which by modern standards is probably one of the more exceptional cold spells relative to the mean (along with Dec 10, Dec 22) I just don't see anything in that kind of ballpark. That's not to rule out a cool down of course, bit as the mean increases towards the end of the month its going to have to be that bit more impressive. The wait goes on then...

Legitimately a spring day here today, 2nd day this year without any need for a coat personally, though just a shade cold for just a t-shirt

I wonder what sort of figure the 17.9 from 1779 would be if adjusted for climate ìnflation? Given how much we've warmer uve got to think that'd be a 19c month if it happened in todays climate Certainly some interesting years in that list though

WYorksWeather it's tricky because are we seeing less rain days but more extreme falls to make up the difference in summer months? Or is there no real trend. i think its only by studying rainfall days, heavy rainfall days amd the ewp in totality will we get a clearer image of what is going on with summer rain pattern. In terms on this winter enso, I honestly believe it just got too strong too rapidly. I've done studies in the past where the sweet spot on average in terms of AO/NAO tends to be in the low 1.x but there is a pretty sharp drop off once above 1.6c. Of course some months still overcome it such as Feb 83 but they typically come when the el nino is starting to collapse anyways. Clearly things this winter weren't as good as some predicted otherwise we'd have still gotten the synoptic pattern to hold for more than 5 days in January, even if its warmer than the past. Still the lack of cold records is already noteworthy btw. 1 daily cold record since 2015. I think 63 warm ones since then...

Wade Interestingly in terms of extreme heatwaves it was one of the more sustained ones, hence why we absolutely obliterated the mins, because often the central core of the plume is already getting ejected eastwards by the time it gets to the UK, hence why we might sneak to 36-38c and then see a line of storms come in to clear it out. On 18-`19th the plume was big enough that when the push eastward did happen it took quite some time to eject out of the way, so much that the plume lasted throughout the night and took towards the back half of the 19th to get replaced, by which time eastern parts had been under the extreme air for 36hrs. I'm not saying that it was the perfect plume, but I do think it was well into the top 0.1% of what is possible given just how extreme the break was in the CET. Even if you take out CC warming of about 1.2c, it still would have obliterated the old UK/CET mean. The max record would have been a smaller jump mind you. Still for it to be 2.8c warmer than the next warmest day by CET is exceptional, and thats a record going 350 years strong. Even removing the CC impact, thats still over 1.5c warmer than the previous, still by far the biggest jump up to the next warmest recording.

There are a couple of things that stand out with the Jul 22 spell beyond just the 40c (Which whilst amazing perhaps is one of the lesser feats). For example it obliterated the daily CET record, nothing is even close (the day before in itself was nearly a record I believe) and thats a 350 year record, so on that metric is comfortably the most severe day in modern history. The min temperature record was beaten by something like 3c which is very impressive. The breadth of heat was also outrageous. Normally when a record goes it is the odd 1-2 stations breaking it by maybe 0.5-1c. In this heatwave 46 different stations exceeded the previous record and many more beat their all time records as well. The best way to view the exceptional nature of it is to compare with other exceptional days: The day before was probably the hottest day for a fair part of England and Wales but was in the same sort of ballpark as 03 and 19, but for England in particular the 19th July was absolutely another level above anything ever seen before. Its perhaps easy to underestimate just how extreme that event was. I've no doubt in a warming world this will happen again, but I think we are still some way off from it being even a uncommon occurrence, at least to the extent it was.

I'd guess 43c is probably at the very very top end of what is in theory possible here, it would require just about perfection in every single element. Even in a world around the 1.5c mark I still think that maybe too far.

In Absence of True Seasons While of course we are seasonal its also true that we could just as easily have 10c and rain in October, January or April. It becomes rarer as we head into late spring and summer but I've even seen July days basically be of similar calibre to the Feb just gone. Most of the country broadly sits between 5-20c for about 9 months of the year. The far north and south/SE maybe a little less due to being warmer/colder.

Down here it's not actually been too bad, basically about as average as you can get. There have been some poor days but I've been lucky to be far enough south to be in the breaks which has made a difference. Next week isn't looking as promising though reverting back to a very mild SW flow again.

Whilst January was fairly modest, February near record breaking mildness has probably put a 11c CET at least into contention again, especially if March also comes in above normal. We will lose ground on the rolling EWP as Mar was exceptionally wet last year, and whilst it does look wet on the models, I'm not seeing anything yet to that kind of level, but May-June was a fairly dry combo so if either of those months come in considerably wet we'd have a high chance of breaking the all time rolling 12 month EWP.

CryoraptorA303 It probably was of the scale of the NW Canada heat anomaly at 850hpa considering we aren't even quite at peak summer in late June. Here was the 25c in the far SW (25.8c at Cambourne I think?) Kent got to about 24-25c briefly on the Saturday but by then it was moving out, akin to the Jul 22 shot. The thicknesses I believe were the highest ever recorded (though I'm not sure if that has now been beaten by July 22, it'd be close either way) but the far south had about 60hrs under 20c at 850hpa. The peak intensity was maybe a shade under Jul 22, but longer holding and more than comparable when you put the two against each other., Using the usual Skew-T average profile it was worked out such a flow was theoretically capable of a 41-42, maybe a rounded up 43c given thickness, 850hpa temperatures and peak solar warming. Of course we probably would not have gotten that theoretical temperature but I'm sure it would have utterly smashed the previous record for June given how high the Jul 22 thrust went. Its interesting that just a month later we did get a properly oriented blast for the record, albeit more limited in some respects at higher levels.

CryoraptorA303 In fact that June 2019 flow was one of the hottest ever recorded (I think 25.8c was recorded in the SW at 850hpa, 24-25c was recorded in Kent on the 29th), it was roughly a similar intensity as the Jul 22 heatwave, though more limited in terms of how far north the most intense heat got and obviously severely nerfed due to the undercut easterly (so much so places ended up under a modest inversion close to the east coast such was the uppers) I remember a pro met on another forum calculated that under perfect conditions that flow was capable of a 40-42c, the uppers were a hair lower but thickness a hair higher than in the Jul 22 heatwave. I had serious doubts at the time but seeing how the July 2022 heatwave evolved that 2019 flow probably would have been capable were it not for that undercut. It'd have basically been of a similar calibre to that extreme NW Canada heatwave had it come off, but I suppose those are real rare beasts for a good reason. I've no doubts that the June record will go within the next 5-10 years.