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DEW
  • DEW
  • Advanced Member
19 February 2024 08:01:51
WX charts showing more of Europe close to norm, still some warmth in the east; in absolute terms the freezing weather is staying to the north of a line east from the Baltic, but slowly cooling as well elsewhere, with particular areas of such cool weather showing up e.g the Highlands, N Spain, S Germany. Heavy rain in week 1 from Britain down through France to Italy; in week 2 Europe is generally damp but the heavy stuff is reserved for the Pyrenees, Italy and Greece.

GFS Op - zonal W-lies and fairly mild to start with, then from Thu 22nd LP dips down to 955mb Fair Isle with a cold core affecting Scotland and strong polar  maritime NW-lies elsewhere. This slowly moves off NE-wards, not filling by much, and bringing a secondary LP from near Iceland with a cold pool down to N France 975mb with E-lies setting in Mon 26th. This LP drifts off SE-wards but pressure rises only a little afterwards, and a new LP 980mb passes E-wards across Scotland Sat 2nd before HP moves in from the SW (mild and dry?) to cover Britain 1035mb Wed 6th.

ECM - similar to GFS but the LP in N France is shallower at 995mb, and there is a pressure rise to follow, though  by end of run Thu 29th pressure is dropping and polar maritime NW-lies are again threatening.

FAX keeps the main LP anchored N of Scotland from Wed 21st with a complex of fronts crossing Britain over the next 48 hours

GEFS - any mildness disappearing by Thu 22nd and then the mean stays near or a little below norm to Wed 6th with quite good support from ens members (just a chance of a mild burst one day only Mon 26th). Rain from Thu 2nd for a week, heavy and persistent in S & W, patchy in N & E, lighter after that but by no means dry. Snow row figures consistently high at Inverness, occasionally high elsewhere in Scotland.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Rob K
19 February 2024 11:07:06
Looking rather unpleasant for us in the UK but some welcome snow appearing for the Alps at last.
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
fairweather
19 February 2024 11:14:20

Looking rather unpleasant for us in the UK but some welcome snow appearing for the Alps at last.

Originally Posted by: Rob K 


Basically as unpleasant as it could be in the South for the start of Spring. Even cold fans don't like driving cold rain especially when winter has finished!
S.Essex, 42m ASL
Gandalf The White
19 February 2024 13:17:21
Looking at the 06z ensemble suite, there's a remarkably strong signal for a switch to be thrown taking us from mild weather, which will dominate for the first part of this week, to something below average; the transition starting on Thursday; the 850hPa temps fall by typically 7-8c.  The signal then weakens again towards the latter stages of the run - unsurprisingly.

Several cold runs in the suite but daytime maxima not desperately cold, reflecting that we're at the tail end of winter.

ECM ensemble mean 10hPa wind forecast shows winds reversing in the first week of March and remaining that way for the rest of the month.

https://charts.ecmwf.int/products/extended-zonal-mean-zonal-wind?area=nh&base_time=202402180000 
 
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


Zubzero
19 February 2024 19:24:40
Poor old Model Output Thread. 

Relegated to the 2nd page, not one single post on an evening in mid February. 

Oh how the mighty have fallen. Ecm puts the boot in.   https://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=0&type=0&archive=0 

See you next year old friend. 
Gandalf The White
19 February 2024 20:46:00

Poor old Model Output Thread. 

Relegated to the 2nd page, not one single post on an evening in mid February. 

Oh how the mighty have fallen. Ecm puts the boot in.   https://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=0&type=0&archive=0 

See you next year old friend. 

Originally Posted by: Zubzero 



It’s surprisingly quiet, since there’s a lot of interest in the output, even if not much encouragement for a decent cold spell.

Today’s update of the ECM ensemble 10hPa winds shows a more marked reversal kicking in two weeks from now and lasting for 3 weeks.  Hard to believe it won’t have any effect at all, but as always there’s no guarantee.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


BJBlake
20 February 2024 00:33:01
Yes - quiet - pub run not exactly helping much, but agree, there is a lot of potential. I guess this is has been another “nearly, but never going to verify winter” - though for any Codge like ‘Mildiies’ the relentless record mildness and record wetness are notable, if just about as depressing for ‘coldies’,  as a Trump election victory, and the pervading inevitability of a Putin victory in the face of western complacency to the Ukraine need for funds and weapons - would be - to anyone sane and who treasured world cooperation and democracy!! 
Brecklands, South Norfolk 28m ASL
DEW
  • DEW
  • Advanced Member
20 February 2024 08:49:23
WX charts show, with respect to average, N-s banding with W Europe cool, mid Europe from Finland to Greece well above norm (which doesn't prevent Finland being freezing), very cold Urals and E-wards. In absolute terms, the freezing area extends from S Scandinavia to the Caspian, random patches of cooler weather in Europe in week 1, these becoming less prevalent in week 2. Pptn in week 1 Norway - Britain - France - W Med, rotating slightly in week 2 Britain - France - W and E Med.

GFS Op - current mild SW-lies going backing NW-ly by Fri 23rd under control of LP 950mb Fair Isle with trough extending S covering Britain, filling and moving S to 1000mb Cornwall Mon 26th and so on to Balearics. Slight rise of pressure behind not lasting as new LP sets up W of Ireland 985mb Fri 1st with general SW-lies. This hangs around, sometimes closer, sometimes further away, and then there's a repeat with part of this sliding away S-wards, slight rise of pressure, new LP this time Rockall Thu 7th 985mb.

ECM - takes the LP Fri 23rd closer to Norway but Britain still under cold NW-lies. The LP over S England Mon 26th derives from a secondary in the NW-ly flow (a distinction without a difference?) but the pressure rise is stronger to follow. The new LP Fri 1st comes in from the N, not the W, and is positioned 975mb N Sea with NW-lies not SW-lies.

GEFS - end of mild weather Thu 22nd, sharp drop to norm or a little below, edging up slightly towards Thu 7th, ens members mostly clustered around the mean.  Rain heavy and frequent over the next week and again around Mon 4th in the S and W, smaller amounts and more spread out in N & E, but no prolonged spell of dry weather. Snow row figures which were quite high for Inverness yesterday have halved.
 
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
fairweather
20 February 2024 10:58:31

It’s surprisingly quiet, since there’s a lot of interest in the output, even if not much encouragement for a decent cold spell.

Today’s update of the ECM ensemble 10hPa winds shows a more marked reversal kicking in two weeks from now and lasting for 3 weeks.  Hard to believe it won’t have any effect at all, but as always there’s no guarantee.

Originally Posted by: Gandalf The White 


It looks like it will have an effect, dragging the early March mean down to below average leading to spells of cold  wet weather - hence the lack of interest as nobody likes that - do they?
S.Essex, 42m ASL
Retron
20 February 2024 11:02:27

It looks like it will have an effect, dragging the early March mean down to below average leading to spells of cold  wet weather - hence the lack of interest as nobody likes that - do they?

Originally Posted by: fairweather 


You know I do, I'll take cold weather whenever I can - especially as it's so rare these days.

Regarding the SSW:

https://charts.ecmwf.int/products/extended-zonal-mean-zonal-wind?area=nh&base_time=202402190000 

Although it shows the vortex regrouping a bit by the end, I do wonder if we might see an early final warming this year!
 
Leysdown, north Kent
Ally Pally Snowman
20 February 2024 11:49:31

You know I do, I'll take cold weather whenever I can - especially as it's so rare these days.

Regarding the SSW:

https://charts.ecmwf.int/products/extended-zonal-mean-zonal-wind?area=nh&base_time=202402190000 

Although it shows the vortex regrouping a bit by the end, I do wonder if we might see an early final warming this year!
 

Originally Posted by: Retron 



Definitely looking like an early warming this year.  I think 2016 had one at a similar time so not unprecedented. 
 
Bishop's Stortford 85m ASL.
Gandalf The White
20 February 2024 13:05:52

Definitely looking like an early warming this year.  I think 2016 had one at a similar time so not unprecedented. 
 

Originally Posted by: Ally Pally Snowman 



No, but the forecast ensemble mean dips well below the 90th percentile; I’d guess down around the 95th, so pretty rare.  Indeed a cluster of runs look to be down around the very bottom of the spread, if not beyond.

https://charts.ecmwf.int/products/extended-zonal-mean-zonal-wind?area=nh&base_time=202402190000 
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


DPower
20 February 2024 21:26:47
Very little confidence in gfs strat forecasts but the 12z profile were it to be anywhere near accurate would certainly perk my interest going through March. I known its not winter but it would could still pack a punch if the strat forcing delivered the right synoptics. Should get a better idea over the next week whether anything noteworthy is on the horizon, if not then like many others my attention will be drawn to warmer settled weather.  
fairweather
20 February 2024 22:33:00

You know I do, I'll take cold weather whenever I can - especially as it's so rare these days.

Regarding the SSW:

https://charts.ecmwf.int/products/extended-zonal-mean-zonal-wind?area=nh&base_time=202402190000 

Although it shows the vortex regrouping a bit by the end, I do wonder if we might see an early final warming this year!
 

Originally Posted by: Retron 


I know you like cold frosty weather and snow and don't like it hot/warm but hadn't realised you liked cold rain and gales.
S.Essex, 42m ASL
Retron
21 February 2024 03:46:02

I know you like cold frosty weather and snow and don't like it hot/warm but hadn't realised you liked cold rain and gales.

Originally Posted by: fairweather 


I don't like gales, but don't mind cold rain - even if it's a bit frustrating that a degree or two lower might have brought snow instead. It's very rare you get both together, FWIW!

(The reason is that gales tend to imply a raging jet nearby, which inevitably means SW'lies and a mild airmass being involved. All the spells of strong winds this winter have followed this pattern, with a surge of mild air accompanying the rain, followed by colder air as the system pulls away and winds ease).

 
Leysdown, north Kent
DEW
  • DEW
  • Advanced Member
21 February 2024 08:29:57
WX charts - only 'subtle changes' (to borrow a phrase from BBC weather forecasters) over the next two weeks. Freezing conditions continue over Scandinavia and points E and SE of there, and the N-S banding noted yesterday also continues, W Europe a little below norm, C Europe considerably above, and Urals E-wards much below. If anything week 1 has colder weather for Britain with not quite as cold for Germany/Poland, the situation reversing in week 2. Pptn pattern has shifted somewhat - week 1 heavy for Atlantic coastal countries esp N Spain and S England, less in the Med than shown yesterday, week 2 the pptn retreats into the Atlantic only affecting NW Spain and SW Ireland, while more appears in the E Med, ut the only really dry area is the Baltic.

GFS Op - Fri 23rd LP with cold core 965mb S Iceland with Britain in its circulation and cool/cold NW-lies; Sun 25th this has stalled as it comes up against Russian HP and filled leaving Britain with local shallow LPs (Shetland, N Sea, Cornwall ca 995mb) ; Tue 27th, the last of these has deepened and moved S to Spain as ridge of HP from SW follows; Fri 1st, trough to W of Ireland 995mb again deepening and running down to Spain; Wed 6th HP coming from the north covers Britain 1030mb to see out the sequence, while Arctic air floods into C Europe.

ECM - Sun 25th, the Cornish LP is deeper 990mb before moving away; Tue 27th HP more transient; Fri 1st not so much a trough as defined LP 985mb N Ireland, and that then retreating N-wards .

GEFS - mean temps soon dropping to a little below norm and then from around the end of the month a little above norm, quite good clustering of ens members around the mean until later on (say, Wed 6th) when some big swings. Rain most likely during the next 5 or 6 days (but very little of this in Scotland and NE England), then again around Sun 3rd (the far NE escapes this too) but England never really dry. 
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
ballamar
21 February 2024 16:22:18
Beginning to look like Saturday could be quite wet in the south - rain will be mounting up
Snow Hoper
21 February 2024 16:56:56

Beginning to look like Saturday could be quite wet in the south - rain will be mounting up

Originally Posted by: ballamar 


more likely Sunday based on forecasts I've seen.
Going to war over religion is like killing each other to see who has the better imaginary friend.


Home : Thorndon, Suffolk.
ballamar
21 February 2024 16:58:45

more likely Sunday based on forecasts I've seen.

Originally Posted by: Snow Hoper 



looking at the charts there could be a decent convective period for Saturday as well. 
To be honest just looks wet this weekend !
Rob K
21 February 2024 18:00:19
GFS 12Z is showing some snow shading in the heavier ppn tomorrow and Friday across the south, and not just over the high ground.

https://modeles2.meteociel.fr/modeles_gfs/runs/2024022112/54-779.GIF?21-12 

Not sure I believe that but I suppose it could be a bit sleety?

Arpege has much lighter ppn and much milder 850s.
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
Snow Hoper
21 February 2024 18:59:22
If ECM has it's way, Sundays rain could miss the south altogether.
Going to war over religion is like killing each other to see who has the better imaginary friend.


Home : Thorndon, Suffolk.
DEW
  • DEW
  • Advanced Member
21 February 2024 21:24:51

looking at the charts there could be a decent convective period for Saturday as well. 
To be honest just looks wet this weekend !

Originally Posted by: ballamar 



Saturday looks showery but there's a real deluge Sunday into Monday for anywhere S of Birmingham.
https://www.metoffice.gov.uk/weather/maps-and-charts/rainfall-radar-forecast-map# 


Synoptics are perfect for a memorable blizzard, FAX has the classic channel low, but temps need to be about 4C cooler. If only ...
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Matty H
22 February 2024 00:24:52

GFS 12Z is showing some snow shading in the heavier ppn tomorrow and Friday across the south, and not just over the high ground.

https://modeles2.meteociel.fr/modeles_gfs/runs/2024022112/54-779.GIF?21-12 

Not sure I believe that but I suppose it could be a bit sleety?

Arpege has much lighter ppn and much milder 850s.

Originally Posted by: Rob K 



It does that multiple times every winter. Fortunately it’s virtually always rubbish 

Looks wet, but on the VERY bright side we are a week closer to no chance of cold and snow, and that’s what is really amazing about our climate. 
Retron
22 February 2024 05:33:14
The 0z GFS really ramps up the winds down here as the cold front passes through this afternoon/evening.

It has a 5C temperature drop in an hour to go along with 38 gusting to 59mph winds - a gnat's whisker away from a gale, in other words.

MetO is much less bullish, instead with a 2C drop in an hour and winds of 24 gusting to 36.

Arpege/Arome etc are between the two.

It's very unusual for GFS and MetO to be so far apart that there's not even any overlap between the two options!

It's also mentioned in the MetO warning down here, with gusts up to 70mph possible:

A band of heavy, squally rain in expected to move eastwards across England on Thursday with gusts of around 50 mph in a few places very briefly, as well as some hail and thunder. However, there is a small chance of a broader swathe of very strong winds affecting southern and eastern England with gusts of 60 to 70 mph, mostly likely close to English Channel and southern North Sea coasts.

I will, as usual, be hoping that squall line breaks up a bit by the time it gets here... it's those massively out-of-whack gusts which cause the damage, I've noticed.
Leysdown, north Kent
DEW
  • DEW
  • Advanced Member
22 February 2024 07:13:54



I will, as usual, be hoping that squall line breaks up a bit by the time it gets here... it's those massively out-of-whack gusts which cause the damage, I've noticed.

Originally Posted by: Retron 



Gust energy obeys, at least approximately, a square law; e.g. 70 mph compared to 50 mph is as 49 to 25, i.e. double the effect.
59 compared to 38 gives a multiplier of 2.4.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
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