Winter 2023/24 - Discussions & Forecasts

[MP-R]

On 28/11/2023 at 14:31, CryoraptorA303 said:

Honestly, I'm really craving a December 2010 now. It's not going to happen, but I'd really like to see a notably cold and snowy December for some reason, even though January is the one we really want a notable cold snap in this year with the ENSO+/eQBO and not having a notable January cold spell since 2013. We're really overdue a notable January event by now while we only had a notable December snap a year ago. Yet I'd instinctively like to see it in December again

There will be a frigid cold spell in January, mark my words. I'm away from the majority of the month and the last time I was out of the country at length in January was 2013... I was also away during the cold spell this January. You heard it here first.

[Daniel*]

I have produced my winter forecast for winter 2023/24. I am quite bold but I think I justify it well enough.  

Winter 2023/24: A Winter to Remember?

WWW.THESNOWDREAMER.BLOG

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Winter Forecast Headlines: Overall, over the course of the meteorological winter encompassing the months of December, January and February. Temperatures are favoured to be colder than normal to...

 

Edited November 29, 2023 by Daniel*

[In Absence of True Seasons]

Hi all, which is the main Winter 2023 thread? There's this one and the other "chat, ramps, and moans" one? 

Is the other one primarily for moaning? 

[johncam]

1 hour ago, Daniel* said:

I have produced my winter forecast for winter 2023/24. I am quite bold but I think I justify it well enough.  

Winter 2023/24: A Winter to Remember?

WWW.THESNOWDREAMER.BLOG

---

Winter Forecast Headlines: Overall, over the course of the meteorological winter encompassing the months of December, January and February. Temperatures are favoured to be colder than normal to...

 

Thanks Daniel,  very interesting. Do think though that Scottish Ski resorts won't get going until cold returns hopefully as little or no snow at the moment. 

[raz.org.rain]

Something just crossed my mind. Considering the current persistence of cold in Scandinavia and how readily it spills over into Eastern Europe while struggling to establish in the west, would that not favour an SSW occurring in Eastern Europe with Western Europe on the "warm" side? For some reason we assume an SSW will put us on the cold side.

[CryoraptorA303]

30 minutes ago, raz.org.rain said:

it feels like we're due a prolonged hot summer

2022 was only a year ago? And 2018 four years before that. Not like July and August 2019 were particularly wet or mild either. I wouldn't say we're necessarily overdue wet summers (2021 and July 2023), but it's been a while since we had a really wet one with no notable heatwaves or dryness at all (the last one must've been 2015 if you exclude the random 35.7C day at the beginning of July). 2012 is the last summer I can think of that was mild almost the entire way and was also really wet, and it certainly feels like we're underdue another hot and dry summer considering they would normally happen around once every 5-10 years.

2 hours ago, raz.org.rain said:

I think the 2022 record breaking high came out of a Spring drought.

That and extremely hot air being blown across the strait of Dover.

[CryoraptorA303]

5 minutes ago, raz.org.rain said:

Something just crossed my mind. Considering the current persistence of cold in Scandinavia and how readily it spills over into Eastern Europe while struggling to establish in the west, would that not favour an SSW occurring in Eastern Europe with Western Europe on the "warm" side? For some reason we assume an SSW will put us on the cold side.

That depends on a lot of factors.

The SSW itself doesn't occur anywhere, it's a warming of the stratosphere above the arctic caused by the slowdown or reversal of the stratospheric polar vortex which then disrupts surrounding weather. I don't think the resultant effects are much related to the preexisting weather pattern but I could be wrong about that.

[raz.org.rain]

1 hour ago, CryoraptorA303 said:

2022 was only a year ago? And 2018 four years before that. Not like July and August 2019 were particularly wet or mild either. I wouldn't say we're necessarily overdue wet summers (2021 and July 2023), but it's been a while since we had a really wet one with no notable heatwaves or dryness at all (the last one must've been 2015 if you exclude the random 35.7C day at the beginning of July). 2012 is the last summer I can think of that was mild almost the entire way and was also really wet, and it certainly feels like we're underdue another hot and dry summer considering they would normally happen around once every 5-10 years.

That and extremely hot air being blown across the strait of Dover.

 June 2022 was really quite chilly too if I remember right. Off the top of my head I can't think of a year where we've had all three months of summer be consistently hot and dry, one is always wet with comparatively suppressed temperatures it would seem. I guess I should clarify that by prolonged I mean a consistently hot and dry summer period following on from a consistently warm spring. With the effects of climate change and features such as growing Azores High persistence and associated growing Hadley cells I would expect we may see such a summer within the decade. I could be entirely wrong, but the trends generally indicate we are heading that way.

 

edit come to think of it, 2018 probably does fit this description. 2018 certainly did have some very lengthy periods of warm and dry.

Edited November 29, 2023 by raz.org.rain

[LetItSnow!]

36 minutes ago, raz.org.rain said:

 June 2022 was really quite chilly too if I remember right. Off the top of my head I can't think of a year where we've had all three months of summer be consistently hot and dry, one is always wet with comparatively suppressed temperatures it would seem. I guess I should clarify that by prolonged I mean a consistently hot and dry summer period following on from a consistently warm spring. With the effects of climate change and features such as growing Azores High persistence and associated growing Hadley cells I would expect we may see such a summer within the decade. I could be entirely wrong, but the trends generally indicate we are heading that way.

 

edit come to think of it, 2018 probably does fit this description. 2018 certainly did have some very lengthy periods of warm and dry.

June 2022 was warmer than average, but less so than the months surrounding it. There was a cool spell in the first week and some local records falling, but the C.E.T. is 14.9 and most of the month was pretty mild with of course the really hot spell on the 17th. I remember model watching at the time and there was the thread of some exceptional heat due to the 20C mark yet again menacing on our shores. It didn't happen (though the 20C mark did make it) but it didn't matter as almost exactly a month later we broke the 40C mark.

[CryoraptorA303]

25 minutes ago, raz.org.rain said:

June 2022 was really quite chilly too if I remember right

June 2022 was warmer than average. Not anywhere near as exceptional as July or August, but certainly not chilly.

27 minutes ago, raz.org.rain said:

Off the top of my head I can't think of a year where we've had all three months of summer be consistently hot and dry, one is always wet with comparatively suppressed temperatures it would seem

June 2022 was also drier than average.

2018 had the most harshly dry period ever recorded in the UK (including 1976), however the raw stats were ruined by the occasional intense thunderstorm passing through. May 2018 for example:

This May was harshly dry and warm for the entire country, however there was a very intense thunderstorm at the end of the month that passed through the south and elevated precipitation levels. May precip in the south is already quite low on average, so it wasn't hard to get the average rainfall stats up. The weather was also not cooperative with getting extreme heat into the UK at any point during 2018 (outside of April), and the high temperatures were largely driven by the extreme dryness and constant sunshine.

39 minutes ago, raz.org.rain said:

I guess I should clarify that by prolonged I mean a consistently hot and dry summer period following on from a consistently warm spring

Such an event is an extremely hard ask for the UK. The closest we've gotten to something like this is probably 1990 or 2022. 1911 was also dry all the way from January or February but I think the heat only really started in July. 1976 had some brief heat spikes in April and May but the heatwave itself was the only extreme heat all year. The rest of July and August were warm but didn't have notable heat at any point.

43 minutes ago, raz.org.rain said:

With the effects of climate change and features such as growing Azores High persistence and associated growing Hadley cells I would expect we may see such a summer within the decade. I could be entirely wrong, but the trends generally indicate we are heading that way.

I agree that we'll be seeing more of this on a relatively short timescale. Maybe we won't see a 2018 or 2022 again within the decade (although I certainly wouldn't be ruling it out with six more spring-summer periods to go) but by the 2040s we'll be seeing some really extreme weather that we probably aren't seriously entertaining right now. The continued persistence of notable or extreme heatwaves in otherwise "off" years such as this one is quite concerning.

[LetItSnow!]

2 minutes ago, CryoraptorA303 said:

The closest we've gotten to something like this is probably 1990 or 2022.

1989 probably did it. May, July, August (in the south), September and the first half of October were persistently dry, warmer than average and sunny. June 1989 also had a long dry, hot spell in the middle of the month but had a cool, unsettled spell early and late. Apart from that, probably the best extended summer we've ever had. Didn't have the extremes of 1976 or 2022, but was consistently fine. May 1989 was a warmer version of May 2020, and was the sunniest on record at the time 'til beaten by the aforementioned month. I think I read that the summer 1989 is the greatest extended summer on record. Compared to other classics summers, it has a better May and September than 1976, 1995 etc.

[CryoraptorA303]

11 minutes ago, LetItSnow! said:

the really hot spell on the 17th

It wasn't exceptionally hot. 32.7C at Santon Downham set a daily record but it's not all that unusual. 2020, 2019 and 2017 all went higher in June. I know June historically is not the hottest summer month and >30C is not a guarentee in June at all, and 15 years ago 32.7C in June would be fairly notable, but as the other two summer months of 2022 showed, the possibilites are clearly accelerating at a fast pace. The chance of seeing >35.5C in June by the end of the decade is close to 1, imo.

16 minutes ago, LetItSnow! said:

I remember model watching at the time and there was the thread of some exceptional heat due to the 20C mark yet again menacing on our shores

I'm sure you mean 850hPa temps? Considering this is in the same paragraph as:

17 minutes ago, LetItSnow! said:

It didn't happen (though the 20C mark did make it) but it didn't matter as almost exactly a month later we broke the 40C mark.

without any elaboration.

1 minute ago, LetItSnow! said:

1989 probably did it. May, July, August (in the south), September and the first half of October were persistently dry, warmer than average and sunny. June 1989 also had a long dry, hot spell in the middle of the month but had a cool, unsettled spell early and late. Apart from that, probably the best extended summer we've ever had. Didn't have the extremes of 1976 or 2022, but was consistently fine. May 1989 was a warmer version of May 2020, and was the sunniest on record at the time 'til beaten by the aforementioned month. I think I read that the summer 1989 is the greatest extended summer on record. Compared to other classics summers, it has a better May and September than 1976, 1995 etc.

It almost looks like a paleo-2018, just with slightly more breaks.

[LetItSnow!]

Just now, LetItSnow! said:

1989 probably did it. May, July, August (in the south), September and the first half of October were persistently dry, warmer than average and sunny. June 1989 also had a long dry, hot spell in the middle of the month but had a cool, unsettled spell early and late. Apart from that, probably the best extended summer we've ever had. Didn't have the extremes of 1976 or 2022, but was consistently fine. May 1989 was a warmer version of May 2020, and was the sunniest on record at the time 'til beaten by the aforementioned month. I think I read that the summer 1989 is the greatest extended summer on record. Compared to other classics summers, it has a better May and September than 1976, 1995 etc.

 

Just now, CryoraptorA303 said:

 

I'm sure you mean 850hPa temps? Considering this is in the same paragraph as:

without any elaboration.

Well of course I do  At the time some models were showing 36-37C if the 20C mark had moven a bit further. 32.7C is not remarkable but quite impressive for June.

[CryoraptorA303]

14 minutes ago, LetItSnow! said:

 

Well of course I do  At the time some models were showing 36-37C if the 20C mark had moven a bit further. 32.7C is not remarkable but quite impressive for June.

We've had quite a few attempts at it recently. 2019 comes to mind. Not sure if June 2017 was really much of an attempt at >35.5C but its certainly still the most exceptional June heatwave since 76, not that there's much competition. I think a lot of it has been down to the pure luck of nothing really serious materialising in June yet. As I said, we'll see these kinds of temps in June in the next few years.

Edited November 29, 2023 by CryoraptorA303

[reef]

Any chance we can discuss winter in the winter thread? Any more off topic will be deleted. Thanks.

[CryoraptorA303]

3 minutes ago, reef said:

Any chance we can discuss winter in the winter thread? Any more off topic will be deleted. Thanks.

Nope, winter has been permanently banned from the UK

[bluearmy]

CANSIPS update 

no surprise it’s not been mentioned this morning 

looks ok for feb from a coldie perspective but jan and feb are down on the  run - jan especially so 

[Don]

5 hours ago, bluearmy said:

CANSIPS update 

no surprise it’s not been mentioned this morning 

looks ok for feb from a coldie perspective but jan and feb are down on the  run - jan especially so 

Lets hope the other long rangers don't follow suite!

[damianslaw]

Its the 1 December. My thoughts taking cues from factors such as atlantic SST's, El Nino, QBO and behaviour of the jet recently, I'd say our highest chance of a colder than average winter since 12-13. Will it though? Law of averages seems stacked against cold nowadays, but the 8-18 Dec 22 proved substantive cold can still be had and the current cold spell I feel has surprised many including me.

There was something about how the summer panned out that made me sit up and think things might not be quite so normal this year..

I'll play cautious and go for an average winter, would love to go with my gut and say below though.. I feel there is a high chance of some signficant cold this winter at times.

December - ending up near average, slightly above but a 30% chance of being below. The second week does look quite mild cancelling out the early cold. Sevond half very uncertain. A change to much colder before months end quite probable perhaps not quite in time for christmas, but may arrive before. 

January- below average slightly, possibly well below. Southerly jet and northern heights but we may pull in milder southerlies at times with a west based NAO.

February - cautiously go average, but could be coldest month if we see a SSW, the jet more southerly.

A very snowy winter for northern high ground and possibly low ground if we see cold dig in. 

An exciting winter ahead if you don't like seeing endless zonal south westerlies. 

Edited December 1, 2023 by damianslaw

[CryoraptorA303]

January is my bet for big cold this year. Overall, I'd say this winter will be colder than many in the 21st century and has the potential to be the coldest so far. December will have westerly intrusions but those will die off as winter goes on. I don't see an early spring happening. March will also be colder than average. Significant snowfall most likely in January with February also seeing potential snowfall. My (very unprofessional) forecast is a watered down 2009/10 initially with repeated cold dispersed between milder intrusions in December, the first major snowy cold snap in January, and then a more typical late winter setup with a Scandi high in February and quite persistent dry cold after an initial plastering. This may persist into March and we could even see another snowfall. I don't really see eye to eye with the seasonals re: the precip anomaly, I see drier than average if anything.

16 minutes ago, damianslaw said:

A change to much colder before months end quite probable perhaps not quite in time for christmas, but may arrive before

It's been a long time since we've had late December-new years cold, surely we're due some this time.

[damianslaw]

45 minutes ago, CryoraptorA303 said:

January is my bet for big cold this year. Overall, I'd say this winter will be colder than many in the 21st century and has the potential to be the coldest so far. December will have westerly intrusions but those will die off as winter goes on. I don't see an early spring happening. March will also be colder than average. Significant snowfall most likely in January with February also seeing potential snowfall. My (very unprofessional) forecast is a watered down 2009/10 initially with repeated cold dispersed between milder intrusions in December, the first major snowy cold snap in January, and then a more typical late winter setup with a Scandi high in February and quite persistent dry cold after an initial plastering. This may persist into March and we could even see another snowfall. I don't really see eye to eye with the seasonals re: the precip anomaly, I see drier than average if anything.

It's been a long time since we've had late December-new years cold, surely we're due some this time.

2020 brought a cold end to the year lasting into the New Year.

The last notably cold end to the year and start to a New Year was way back in 2009-10. 10-11 was quite cold but nothing signficant. 2008-09 also cold.

We've had far too many mild ends to years and starts of new ones recently. The last 2 years especially so.

The week before christmas has been mild last 12 years!. 

Edited December 1, 2023 by damianslaw

[CryoraptorA303]

25 minutes ago, damianslaw said:

2020 brought a cold end to the year lasting into the New Year.

I don't really remember January 2021 being that cold. I think it's partly because we were in lockdown at the time so I wasn't going out in the cold, and partly because it hit the north harder than the south. I'd even personally rate January 2023 being a bit colder here purely from memory. I only remember it getting cold into February and the February cold spell where we got a decent covering of snow for a few days. My birthday was on the 7th and it was snowing for most of the day although not settling yet. The next morning was when much of the snow had settled overnight as it got cold. Towards the end of that cold spell I also remember the really cold night when it got down to around -7C here, which was the coldest since BFTE when it got down to -11C here (which must be the coldest since 87 at East Malling). I think it bottomed out around -8C here in December 2022 which will now be the coldest since BFTE. No idea how low Dec 2010 went.

40 minutes ago, damianslaw said:

The last notably cold end to the year and start to a New Year was way back in 2009-10. 10-11 was quite cold but nothing signficant. 2008-09 also cold.

Even then, those were overall milder interludes in otherwise very notable cold spells. The last time we had an actual seriously cold new years period appears to be 1996/97.

43 minutes ago, damianslaw said:

The week before christmas has been mild last 12 years!.

That's true as well. December 2022 was the first time we had any kind of real cold in the entire month since 2010. We had an attempt in 2012 but it went nowhere. After that it was either mild and wet or dry and not-cold in the case of 2016. The few times in that period between 2013 and 2022 we did get a notable cold spell it was in February or March. Now we had a decent cold spell in December, it's January's turn this year.

[Mike Poole]

17 hours ago, bluearmy said:

CANSIPS update 

no surprise it’s not been mentioned this morning 

looks ok for feb from a coldie perspective but jan and feb are down on the  run - jan especially so 

No, Jan was very much not what I think we were expecting.  Feb (and Mar, for what it’s worth) look very blocked with clear Greenland high anomaly.  

Here’s the charts:

Edited December 2, 2023 by Mike Poole

[CryoraptorA303]

23 minutes ago, Mike Poole said:

No, Jan was very much not what I think we were expecting.  Feb (and Mar, for what it’s worth) look very blocked with clear Greenland high anomaly.  

Here’s the charts:

Not that I'd be complaining if we get a very cold February-March period, but it will have been the eleventh January without anything major. Surely January can't be missed out again this time. Maybe more towards the second half of the month but I can't shake the gut feeling of a significant January cold snap coming.

Having said that, a bunch of WAIs coming up lately were February-centric cold winters with archetypal late winter Scandi highs. So maybe there's some credence to be had.

[bluearmy]

1 hour ago, Mike Poole said:

No, Jan was very much not what I think we were expecting.  Feb (and Mar, for what it’s worth) look very blocked with clear Greenland high anomaly.  

Here’s the charts:

Can you check out the mslp anoms on that site Mike ?

weatherbell has a less strong anom take on its charts and certainly doesn't see a surface high anom over Greenland for feb and instead has one over scandi. I’m wondering if weatherbell charts are wrong