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Rob K
11 February 2024 09:19:08
Well I have long since given up seeing anything wintry at home so my focus is now on looking at the ensembles for Austria to see whether there might be any snow there in 5 weeks' time.

The GEFS is looking a bit more encouraging on that front with the mean pressure dropping to about 1010mb for the last week of the run, 850s well below zero and plenty of precipitation around. Masses of scatter though.
Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
David M Porter
11 February 2024 09:43:30

You have me there Peter. I cannot disagree with your point. However, I don’t think I remember a time when the models have chopped and changed so wildly over cold and mild scenarios. Yet it is seemingly always the milder end of these scenarios that verifies. If the models have the correct data, then it is simply that the weather has got more chaotic and faster churning than in the past - perhaps due to the added heat. I don't know, I just hypothesise to try to explain what we witness. i don't pretend to have the answers, but the subject is fascinating. Moreover, the warming is deeply sad for cold weather fans, but tragic for ecosystems, and ultimately for people too, living with the consequences of it.

Originally Posted by: BJBlake 



On your last point, the warming that has taken place generally doesn't appear to have prevented cold from happening in other parts of the world in recent times, and some pretty severe cold at that which has rivalled cold spells from the dim & distant past. Tallyho and one or two other members mentioned this earlier in the thread. I think that one factor which has likely gone against our part of the world in terms of cold this season has been the strong El Nino which I believe still has some time to run yet.

On that point, didn't we have a a La Nina event only last winter? My understanding has long been that La Nina normally follows El Nino so it is interesting that we have had another El Nino so soon after the last La Nina. Presumably, there will now be one of the latter events again sometime in the near future.

Apologies for being off-topic.
Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
tallyho_83
11 February 2024 11:28:43
The AO is meant to go into a negative phase and almost record breaking negative yet there is no HLB in the latest 06z runs. It looks zonal throughout. Despite thr SSW. 
Home Location - Kellands Lane, Okehampton, Devon (200m ASL)
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Magical Moon
www.magical-moon.com


David M Porter
11 February 2024 11:47:30

The AO is meant to go into a negative phase and almost record breaking negative yet there is no HLB in the latest 06z runs. It looks zonal throughout. Despite thr SSW. 

Originally Posted by: tallyho_83 



Until such times as the models properly get to grips with the SSW and what, if any, effect it has on the synpoptics and pressure patterns, I think we can expect there to be a fair amount of swings in the output and little run-to-run consistency in the meantime. I mentioned two or three weeks ago that it usually takes the models a bit of time to fully work out the effect of a SSW on pressure patterns. Therefore, I think that as things stand, it is too soon to be expecting the models to be taking account of the SSW whatever it leads to, if anything at all.🙂
Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
Snow Hoper
11 February 2024 11:50:33
For me, I have to give credit to the garden footpath system, for not really having anything to do with the modeled blocking that the others were playing around with. I don't normally champion the GFS, but its performance was much better than the others this time round I have to say.

There's always next winter I suppose!
Going to war over religion is like killing each other to see who has the better imaginary friend.


Home : Thorndon, Suffolk.
+1
CField
11 February 2024 12:17:16
Until we get another run or if we get another run ever again  of below average CET temps I feel the UK will be devoid of any deep cold...
Favourite snowstorm
Famous channel low
Dec 31st 1978
Hastings East Sussex
Foot of level snow severe drifting
Next day max temp -4 degrees Celsius
Rob K
11 February 2024 12:32:42

The AO is meant to go into a negative phase and almost record breaking negative yet there is no HLB in the latest 06z runs. It looks zonal throughout. Despite thr SSW. 

Originally Posted by: tallyho_83 


How is that possible? A negative AO means high latitude blocking, by definition!
Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
doctormog
11 February 2024 12:37:26
Just a wild shot in the dark, but perhaps the AO “forecast” wasn’t based solely on this morning’s 06z GFS operational run?
Aberdeen
Current conditions (personal WS) 
nsrobins
11 February 2024 12:47:22

For me, I have to give credit to the garden footpath system, for not really having anything to do with the modeled blocking that the others were playing around with. I don't normally champion the GFS, but its performance was much better than the others this time round I have to say.

There's always next winter I suppose!

Originally Posted by: Snow Hoper 



Agreed. GFS has had the hop on the other big players on several occasions this ‘winter’. I’d also be interested to know what the UKMet make of what is looking like a fail of their longer term predictions.
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
David M Porter
11 February 2024 15:31:54

Agreed. GFS has had the hop on the other big players on several occasions this ‘winter’. I’d also be interested to know what the UKMet make of what is looking like a fail of their longer term predictions.

Originally Posted by: nsrobins 



It would be interesting to see the model verification stats since the start of December to see officially which model(s) has/have verified the best in that time, Neil.🙂
Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
Retron
11 February 2024 15:46:19

It would be interesting to see the model verification stats since the start of December to see officially which model(s) has/have verified the best in that time, Neil.🙂

Originally Posted by: David M Porter 


You might be able to find them if you dig around, but for the past month we have this - for 850hPa temperature, rather than the less useful (IMO) 500hPa correlation at T+120. It's much the same for the other parameters, and even for the last year (GEM and GFS tend to trade places, but ECM is the undisputed leader, and MetO usually comes second).

https://emc.ncep.noaa.gov/users/verification/global/gfs/ops/grid2grid_all_models/acc/ 

ECM: 0.907
MetO: 0.885
GFS: 0.876
GEM: 0.869
India model: 0.849
NOGAPS: 0.845
CFS: 0.812
Leysdown, north Kent
Chunky Pea
11 February 2024 15:51:54

The AO is meant to go into a negative phase and almost record breaking negative yet there is no HLB in the latest 06z runs. It looks zonal throughout. Despite thr SSW. 

Originally Posted by: tallyho_83 



If you look at the EC day 10 run, the arctic is largely dominated by high pressure, though more on the Alaskan / Siberian side. 

https://www.wetterzentrale.de/maps/ECMAVGNH00_240_2.png 



 
Current Conditions
https://t.ly/MEYqg 

"You don't have to know anything to have an opinion"
--Roger P, 12/Oct/2022
BJBlake
11 February 2024 16:38:19

On your last point, the warming that has taken place generally doesn't appear to have prevented cold from happening in other parts of the world in recent times, and some pretty severe cold at that which has rivalled cold spells from the dim & distant past. Tallyho and one or two other members mentioned this earlier in the thread. I think that one factor which has likely gone against our part of the world in terms of cold this season has been the strong El Nino which I believe still has some time to run yet.

On that point, didn't we have a a La Nina event only last winter? My understanding has long been that La Nina normally follows El Nino so it is interesting that we have had another El Nino so soon after the last La Nina. Presumably, there will now be one of the latter events again sometime in the near future.

Apologies for being off-topic.

Originally Posted by: David M Porter 



I think the point that’s been made before by others is true, that global warming has caused more SSWs and displacements of the polar vortex, which warms the poles fastest and destabilises the ice/ increases its melt, and masks climate change for mid latitudes, especially continental countries, such as the USA, which adds to their higher rates of climate change scepticism. Yet these extreme cold air displacements are in fact evidence of climate change. I think this is far less common in ocean dominated countries like ours, where sea temperatures are so much higher than normal, hence our milder winters in recent times. The El Niño is a strong one, and this has poor correlations with cold weather for the UK. Joe D’Aleo has done exhaustive correlations in this regard. His work demonstrated that it was weak El Niños or the nothing years (La Nada), that were best associated with cold weather outbreaks with the eastern seaboard of the USA and the UK (along with other parts of NW Europe).
Brecklands, South Norfolk 28m ASL
+1
David M Porter
11 February 2024 17:03:32

I think the point that’s been made before by others is true, that global warming has caused more SSWs and displacements of the polar vortex, which warms the poles fastest and destabilises the ice/ increases its melt, and masks climate change for mid latitudes, especially continental countries, such as the USA, which adds to their higher rates of climate change scepticism. Yet these extreme cold air displacements are in fact evidence of climate change. I think this is far less common in ocean dominated countries like ours, where sea temperatures are so much higher than normal, hence our milder winters in recent times. The El Niño is a strong one, and this has poor correlations with cold weather for the UK. Joe D’Aleo has done exhaustive correlations in this regard. His work demonstrated that it was weak El Niños or the nothing years (La Nada), that were best associated with cold weather outbreaks with the eastern seaboard of the USA and the UK (along with other parts of NW Europe).

Originally Posted by: BJBlake 



I had thought that SSWs were a completely natural occurence that happen from time to time and are unconnected to AGW, but maybe you are better informed about them than I am.

What I do recall is that they were hardly ever, if at all, mentioned on this forum prior to about 2010. There was one such event in (I think) February of that year which helped to extend the cold that had dominated that winter since mid-December 2009.
Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
Hippydave
11 February 2024 18:24:25
As has seemed to be the case for a while, some glimmers of interest (from a cold POV) on the 12z ops so far but nothing more than that (UKM and GEM, GFS is broadly 'pants').

On the GFS having had the hop, it's like saying a team scored 3 tries at rugby when the score was 76-15 in favour of the opposition. The stats almost always show it comes third or fourth verification wise. There's obviously going to be a few occasions when it does better and actually recently its tendency to ramp up the Atlantic (my perception) has worked in its favour as the extra energy it's been sticking in has materialised and resulted in a flattening of the pattern. 

All that said the stats also show there's really not a lot of difference between the 3-4 'best' models and it's rare one will get things completely wrong, it's usually degrees of difference. I guess the issue for our little part of the globe is that the wider picture can be essentially correct but at a local level the weather on the ground can be very different. I also still think a lot of the perception of the models is how often we see their output and whether it shows cold or milder -> when you see 4 x GFS ops and ens sets which frequently play with different solutions run to run it's pretty inevitable one of them will be closer to reality than the others and when it's a mild, more unsettled solution after the output has been trending towards blocked and/or potentially colder solutions that one will stick out more. There's also the issue with things like UKMO, where we can see the run ending on a blocked note but no idea how long that blocking would last. If a day or so down the line it then has that block as a temporary interruption in the flow the perception seems to be it's backtracked when it hasn't. 

All IMO of course, no doubt other folks will take a differing view given a lot of that is subjective/opinion (other than the empirically proven stats bit, 😛!). 


 
Home: Tunbridge Wells
Work: Tonbridge
ballamar
11 February 2024 19:41:35
ECM offers hope for last week of Feb and to an extent GEM. Still could be some cold left in this winter
David M Porter
11 February 2024 23:19:16

You might be able to find them if you dig around, but for the past month we have this - for 850hPa temperature, rather than the less useful (IMO) 500hPa correlation at T+120. It's much the same for the other parameters, and even for the last year (GEM and GFS tend to trade places, but ECM is the undisputed leader, and MetO usually comes second).

https://emc.ncep.noaa.gov/users/verification/global/gfs/ops/grid2grid_all_models/acc/ 

ECM: 0.907
MetO: 0.885
GFS: 0.876
GEM: 0.869
India model: 0.849
NOGAPS: 0.845
CFS: 0.812

Originally Posted by: Retron 



Thanks Darren. 👍
Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
BJBlake
11 February 2024 23:53:58

I had thought that SSWs were a completely natural occurence that happen from time to time and are unconnected to AGW, but maybe you are better informed about them than I am.

What I do recall is that they were hardly ever, if at all, mentioned on this forum prior to about 2010. There was one such event in (I think) February of that year which helped to extend the cold that had dominated that winter since mid-December 2009.

Originally Posted by: David M Porter 



Yes the evidence is that SSWs are getting more frequent and of longer duration and strength since the 1980s, and this is thought to be due to climate change.
Brecklands, South Norfolk 28m ASL
MRayner
12 February 2024 07:33:32
GEFS cluster showing a possible colder period starting 22Feb. 
Location Whisky 🥃 country, Cragganmore ,Moray, 440 AMSL
BJBlake
12 February 2024 07:59:42

GEFS cluster showing a possible colder period starting 22Feb. 

Originally Posted by: MRayner 

Yes 11 of the perts have cold or very cold endings into FI, but notably not the Op or the control. We’ll see. Last chance saloon for a meaningful cold spell.
Brecklands, South Norfolk 28m ASL
doctormog
12 February 2024 08:13:51

Yes 11 of the perts have cold or very cold endings into FI, but notably not the Op or the control. We’ll see. Last chance saloon for a meaningful cold spell.

Originally Posted by: BJBlake 



I would argue that, for what it’s worth, the HFS 00z op run does indeed have a cold ending.

There has been evidence over the last few runs of colder clustering towards the end of February. Far too early to draw any conclusions just yet given the timescale involved.
Aberdeen
Current conditions (personal WS) 
David M Porter
12 February 2024 08:27:30

I would argue that, for what it’s worth, the HFS 00z op run does indeed have a cold ending.

There has been evidence over the last few runs of colder clustering towards the end of February. Far too early to draw any conclusions just yet given the timescale involved.

Originally Posted by: doctormog 



I would agree that the GFS 00z does indeed have a cold ending Michael, certainly rather more so than most if not all the GFS op runs yesterday did.

We shall see what happens going forward to late February. I understand from a video I have just seen on the BBC weather website that the SSW is due to take place around later this week, so we shall see what if any effect it has on the model output over the following days.
Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
DEW
  • DEW
  • Advanced Member
12 February 2024 08:33:43
WX temp charts show the cold remaining in the north, roughly north of a line running through the Baltic, and the rest of Europe well above norm. A large mass of very cold air over N Russia disappears in week 2, and just a suggestion of something colder moving down from Iceland towards Scotland. Pptn pattern much as yesterday, week 1 from Britain across to the Baltic and in week 2 from Britain down to the Alps.

GFS Op - HP to the south and LP to the north waltzing around each other with, to start with, a general W-ly flow. Up to Thu 15th the HP is to the SE and LP fairly close to the NW so unsettled and mostly SW-lies; then for the next week HP moves closer and more directly to the south so the W-lies become stronger and England at least looks dry; then to Sun 25th HP to the SW and LP to the NE and winds go round to the NW. Finally the LP deepens over Scandinavia and on Wed 28th there are N-lies for all and a secondary LP 980mb Cornwall.

ECM - from Thu 15th the HP is placed more to the west of Britain and minor troughs appear in the N Sea before the HP takes up position centred over Britain 1030mb Wed 21st. 

GEFS - becoming mild at first to a peak around Thu 15th but with frequent rain; most ens members then decline steadily, down to norm by Thu 22nd and then remaining cool; more rain around generally but esp near Sun 25th and at that date quite likely to fall as snow esp in Scotland but also possibly England from the Midlands N-wards.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
+5
The Beast from the East
12 February 2024 10:09:24
Assuming we can avoid the cloud it should be glorious and warm next weekend in the south at least
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speckledjim
12 February 2024 10:12:03

Assuming we can avoid the cloud it should be glorious and warm next weekend in the south at least

Originally Posted by: The Beast from the East 


Beginning to look a lot like Spring 
Thorner, West Yorkshire


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