kold weather

Looks almost certain now we will be above the 61-90 average and thus make it 12/12, and 23/24. Impressive sustained warmth but to be expected in a warming world

Models all have the same broad pattern but the GFS keeps the high close enough to allow for some homegrown cold to develop, the ECM meanwhile keeps it just far enough away that we import, particularly the further west and north you go. Therefore its best not to weigh too much onto any one particular model solution at the moment, since the GFS comes in considerably colder than the ECM would.

This is basically the textbook bartlett high, back in the early days of weather forums this was the example that almost always got brought up as to what a trye bartlett high is: There isn't really alot of difference though between a Euro high and a Bartlett, other than a Bartlett often has the core of the upper high further west than a Euro high often does which tends to mean once they do setup, they have a habit of sticking around for 10-14 days and have a nasty habit of remerging. Its this element that strikes fear into coldies. Its seen as literally wiping out weeks of prime time.

Certainly a chance for an ice day here but it will depend on how quickly that rain moves across, my gut is we may just miss out on it. Still to have gotten a max temperature of -0.8c during the daytime at the start of December is pretty impressive, shades of what we saw last December, though unfortunately its not going to lingering around this time.

I've got the Xmas lights up now, it really does make a surprising difference to the light levels, particularly on days like today which are on the dark side. Its partly why I can cope pretty well for December but find Jan and the first half of Feb such a slog. Still it won't be long before the nights start to draw out again, even if the mornings have some way to go still (by the time we gain 10 mins in the morning, we've gained about 40 in the evening)

Also similar to Feb 86, outrageous cold but it doesn't get mentioned much due to the Snowy winters around it. What last December needed was that big snow event, it did have snow but it was reasonably localised into certain regions. All the memorable cold spells (Jan 10, Dec 10, Feb/Mar 18, etc) have tended to have those near countrywide events. But yeah, Dec 22 was actually temperature wise quite extreme, we nearly broke a cold record date mean (just missed out, ended up 2nd coldest for i think the 15th December), it'd have been the first since I think Mar 18.

Also I don't think it's a bad thing, getting a covering over much of Europe will cool things down after another very warm year. All these things will help tip the balance should any marginal situations crop up, particularly deeper into winter. More than a whiff of 09/10 about the autumn and the way its evolving, we also had a solid moderate/borderline strong el nino that winter as well and this strong el nino has been very atypical thus far in some aspects.

Autumn 23 now looks almost certain to go down as a very wet, already close to the top 30 wettest. It does look drier for the final part of Novber for now which will probably be enough to prevent a top 10 finish, but a top 10% finish seems pretty close to certain now.

December 2022 start was just a hair below normal, the real cold spell didn't really kick in until the 7th December (first 5 days was 4.5c, so cool but not cold IMO) whilst the Feb cold spell had near sub zero CET means basically from day 1 of the month. I suppose my main point was the actual cold spell itself from the date of initiation was more intense both in absolute and relative terms in Dec 22 compared to the Feb 12 cold spell (peak 5 days for example was much colder in 22 than 12, both absolute temps and relative)

Even that isn't strictly true, taking the coldest 12 days in Feb 12 vs Dec 2022 comes out at -0.8c for Feb 12 and -1.1c for Dec 22. The coldest 5 days also were colder in Dec 2022 (-1.1 vs -2.5) and Dec 2022 had the coldest day as well (-4.5c vs -2.8c) By most measures the December 2022 was colder than Feb 12, the only thing Feb 12 has was that it lasted a little longer if you include the last few days of Jan 12 as well.

I think there was one day within that period (something like the 14th or 15th where the CET mean for the day placed it within the top 15 coldest days since winter of 62/63, there were a couple of other days that weren't all that far from that ballpark either. Down here we went through a pretty impressive ice day combo locally, even more so given there was only the slightest hint of snow on the ground. Most days in the south were way below the average for December in that spell (somewhere between 5 to 10c below normal!

I think the issue is this spell is probably going to be so rough that its probably going to be the over riding memory of this autumn, not the exceptionally nice first half of September. I strongly suspect though that this Autumn is destined to be one of the wettest we've had, even an average November would put us into the top 10% wettest Autumns ever, and the models are suggesting we are probably going beyond just average...

I think what it shows is that we can clearly still get pretty impressive cold spells and I've no doubt we can get severe cold months, even allowing a 1-2c warmer world, we should still be capable of getting a sub zero month. I do however think December 2022 was slightly unique in that the cold was basically totally homegrown, so we saw very little modification of the air over the warmer than normal waters, since it basically stagnated in place overland. Most cold months will see a synoptic shift at some point that introduces new airflows that inevitably get moderated warmer than usual by the warmer than normal waters. That didn't happen at all in that 15 day cold period in December 2022. The other problem is we require a more intense synoptic set-up to end up getting the same result as we used to. So a strong cold spell may have needed a 1 in 10/20 year set-up, now might require a 1 in 30/40 year set-up to get the equivalent. It can still happen, particularly in short bursts, it just takes a more impressive evolution to get to that point.

December 2022 cold spell was very impressive indeed, I did some research into the CET which I've sadly forgotten about now but that spell ranks very highly even against the cold spells of the 80s, etc, but for most it lacked the snow required to elevate it into a more memorable spell. December 2022 also highlights another issue though. Because we are so globally warm odds are if you do get a snapback to milder conditions, those milder temperatures will have more punch and lift the CET beyond what you'd expect. December 2022 still came in fairly cold in the CET zone, especially against recent long term means, however we were on 0.4c on the 17th, so to end up above 3c come months end is quite the warm up.

October 2023 ends up with the 4th wettest October ever on the EWP rankings. The first 15 days were a little wetter than normal but the spell since Babet started has been nothing short of exceptionally wet. As of 31st October we are now in the wetter 50% of Autumns, with a clearly very wet start to November to add in still to those figures. Already a wetter than normal year as well so far, so anything added on from this point is just pushing us further up the list. Top 10 easily within reach, though the record would require a pretty exceptional Nov-Dec combo (though we are certainly starting November at the required pace)

Annual rainfall already into the top 70 of the records with a full 2 months left of the year. Instead of it being worryingly dry its becoming an increasingly wet year. 2012 and 2000 are the modern benchmarks for very wet years, though both 2019 and 2020 were also wet years. Odds are by the end of this upcoming weekend we will be comfortably into the top 50 and with over 50 days left, hard to know how high we will go.

2023 October currently sitting in 7th place in the all time ranking with the 31st still to add into the rankings, so probably will move up the rankings further given yesterday did have frontal rain and plenty of showers about elsewhere. Much of coastal CS/SE England and parts of S.Wales have seen quite large totals, since 00z Friday most of the places mentioned are somewhere between 80-120mm, which is for those areas more than the October average, and indeed above the November average.

Not sure that holds as much water as you think, there is still a significant number who walk to school (something like 45-50% of all children do so looking at studies from the govt) so if that was an issue in the past, it would undoubtably still be an issue today I'd imagine.

To be fair the 20th *only* contributed 16.9mm of rainfall across the EWP zone, even taking that out its going to be very comfortably above average by the end of this month, though no denying that whole Babet period was very wet. Anyways, a top 10 wettest October now looks almost certain. Probably be in the top 5 even...

Yeah it certainly can get some decent falls of rain. Then again to get within the ballpark of a seasons average within 7-10 days is still an undeniably very wet period.

The EWP scale currently has 2023 at No.6 of all time upto 27th of October. No doubts either that we will closing in on the top ranking years by the time we get to the end of the 1st week of November. As for October, some places have seen pretty amazing anomalies, Wattisham has already been noted, but due to how wet the last 72hrs has been Thorney Island not far from my neck of the woods that is now a hair away from the record upto the 28th (and today has been very wet down there) so that will also go no doubt. Finally many places in the south and east are now near or over their Autumn expected rainfall, with a very wet spell still upcoming... I suppose its no surprise given how warm the Atlantic is that things would get very wet once the pattern supported it.

Starting to get some legitimately large rainfall totals down in the south coast, since 00z Friday we are now upto 70-100mm quite widely. Given how unsettled this week looks could well see a 7 day total for some parts over 200mm. For some parts that would be big but nothing exceptional, but for the south that would be starting to get into the exceptional bracket

Going to be interesting to see where the 15th Oct - 15th Nov would rank in comparison to other Octobers/November's. Particularly down here in the SE it feels like it's becoming a very wet period.

We are now reaching the point where even an average November rainfall will put this Autumn in the top 10 wettest. I've got a feeling this November may well have frequent bursts of cyclonic activity so we could end up towards the upper end of that top 10, though the very wettest seasons are in a league of their own (Autumn 2000 is literally another level).

Hastings had about 40mm from 00z-09z and there may well be a little more to add on to that this morning. Pretty probable we see a 48hr reading of 100mm somewhere this weekend, very wet by any standard.