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White Meadows
02 December 2022 07:44:09

There is a correlation.

Novembers are often extremely wet (think '09) when the Atlantic troughing fails to get much past the meridian. Essentially, LP becomes slow moving across the UK. That's because there is blocking to our E or NE (usually somewhere around Russia). This buckles the jet to our E and transports warm air N towards the Siberian Arctic. This creates a feedback and eventually the Atlantic jet gets split further west and allows blocking to take hold.

There are also longer term implications of the Russian/Siberian block in terms of the stratosphere. It's the one thing I look for later October/November to guage whether we will see cold early doors.

Over on the other site I said this in late October-

'Very encouraging GFS at D8 for the longer term.
As I point out every year, troughing struggling to get past the meridian is what you want to see as you enter November. Nov 2009 featured this in abundance. To my eyes it looks as though the strat is going to be roughed up slightly over the next couple of weeks.
This is a prelude to a pattern change as we go further into Nov and Dec.
A period of meridional jet stream across the Atlantic looks odds on to me latter Nov/into December. The seasonals concur with this too, which is good.'

Some people saw soggy weather, I interpreted it as a hemsipheric set up loading itself with potential.
 

Originally Posted by: CreweCold 

 
Thanks for the insight. To be honest I've thought the same for a few years now. Every time Novembers have been calm with frosts my heart sank, since 2009. 
Brian Gaze
02 December 2022 07:48:46
ECM op wasn't well supported.  Once the full 50 member ensemble is in it will be easier to see how many runs followed it, but the SD suggests not many.

https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=00&lg=850&lglocation=london 


UserPostedImage
Brian Gaze
Berkhamsted
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"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
doctormog
02 December 2022 07:49:22

Thanks for the insight. To be honest I've thought the same for a few years now. Every time Novembers have been calm with frosts my heart sank, since 2009. 

Originally Posted by: White Meadows 



"Ice in November to bear a duck..."?
Arbroath 1320
02 December 2022 07:53:03

Incredible GFS 00z run for cold weather fans. Probably one of the most impressive we've ever seen.

UserPostedImage

Originally Posted by: Brian Gaze 



Agreed Brian. inevitable downgrades to come, but that run is up there with the most incredible I've seen on my 20 odd years on this forum.

 
GGTTH
Rob K
02 December 2022 08:00:09
GEM is a blinder this morning and GFS also pretty darn good. 

ECM less impressive and loses the cold air from the south but still not bad for the time of year. 

My new heat pump may be getting a good workout before long - so far it hasn't had to deal with subzero temperatures!
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
Rob K
02 December 2022 08:06:52
Just pondering... if (and it's still a big if at this stage) we can get a decent nationwide cold spell and some proper snow before the end of the year then 2022 will certainly be remembered as a classic year for weather, after the record breaking summer we had. 
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
nsrobins
02 December 2022 08:16:18
Something to add to the mix, along with the vagaries of the EC extended (a big mild outlier from 180hrs), is the hint of a cold surface high developing across Scandinavia from Sat. GEM keeps hinting at this and it's trickling in to some of the GEFS suite. 
Enjoying the ride.
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
moomin75
02 December 2022 08:17:25

ECM op wasn't well supported. Once the full 50 member ensemble is in it will be easier to see how many runs followed it, but the SD suggests not many. https://www.theweatheroutlook.com/twodata/ecmwfens.aspx?run=00&lg=850&lglocation=london  

Originally Posted by: Brian Gaze 

Indeed. And, (I don't know how to post images), it is an absolutely enormous pressure outlier on the ECM 0Z.
Witney, Oxfordshire
100m ASL
Rob K
02 December 2022 08:18:32
Talk of Dec 1981 comparisons... IIRC a feature of that 81-82 winter was very low temperatures in slack air (including the English record low I believe?) Would like to see that again. 
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
idot
  • idot
  • Advanced Member
02 December 2022 08:18:44
when did this forum start Brian? I rekon ive been on here since 2002ish/? (lost original account in a platform move i think many years back)

Models are looking good like they aint done in a while. We need the snow to cheer us all!
02 December 2022 08:20:31
UserPostedImage

It is just a slight pressure outlier post day seven 😅
Malcolm UserPostedImage
Wakefield & Gothenburg, SWE
moomin75
02 December 2022 08:24:33
Can someone tell me how to post images? I've never known how to.
Witney, Oxfordshire
100m ASL
DEW
  • DEW
  • Advanced Member
02 December 2022 08:27:39
I'll try and post something which is dispassionate and not too cherry-picked...

WX temp charts for week 1 hold the build-up of cold air (behind the 0C isotherm as a convenient marker) at E Poland before allowing to spread west to E France in week 2, not quite as far as yesterday. Something milder in Biscay, not quite reaching the Channel, and Britain still cold with sub-0C in hilly areas in N & W. Super-cold backup over Siberia has faded though a small patch remains over Norway. Pptn in week 1 on Atlantic with extension to France and Italy expands in week 2 to include Britain and Spain, and eastwards to Ukraine. A very good prospect for snow over hills in UK, some lower ground may be lucky but it's still a long way ahead.

GFS Op - HP over Scandinavia with ridge first to Britain then to Iceland hangs on until Mon 5th when pressure drops over Norway and Brittany to a situation Thu 8th 995mb Finland linked by trough to 1000mb Brittany with Britain in light NE-lies on the edge of the trough. The cold air drifts SW-wards and forms not so much a pool as a puddle over Britain, dispersed and cold rather than very cold, to Sun 11th. This model predicts a series of S-ly tracking LPs for the following week, notably 980mb N Spain with not-so-cold SE-lies Tue 13th, 985 mb E Anglia with much colder NE-lies Sun 18th.

BBC weather last night was showing a much more direct and strong cold N-ly for early next week, and on the radio this morning repeated by Stav Danaos as 'an Arctic N-ly early next week'. This is supported by FAX with the N/NE-lies in place by Tue 6th.

ECM follows GFS at first but by Thu 8th pressure has dropped over Britain (rather than over continental Europe) with more definitely cold air here and the fringe NE-lies pushed off to the Atlantic. The LP over Spain develops two days earlier, on Sun 11th, and instead of drifting E-wards and filling, moves NE-wards to 970mb NE England drawing some very cold air in from Scandinavia especially to NW Britain.

GEM is similar to GFS but emphasises the S-ly positioned lows (they don't track so much as fill) from Thu 8th, 980mb Biscay Fri 9th, 960mb Azores Sun 11th but with less cold SE-lies for much of this time; only on Mon 12th is there a drift of really cold air from the NE.

GEFS mean temps about 5C below norm for the next fortnight (almost up to norm for the S one day only Mon 5th) with good agreement between ens members, chance of pptn increasing through the period. Snow rows consistently 5-10 in the S from Wed 7th, around 10 in Midlands/NW England, 15-20 in Scotland and NE England, 20+ in the Highlands

 
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Caz
  • Caz
  • Advanced Member
02 December 2022 08:49:10

GEM is a blinder this morning and GFS also pretty darn good. 

ECM less impressive and loses the cold air from the south but still not bad for the time of year. 

My new heat pump may be getting a good workout before long - so far it hasn't had to deal with subzero temperatures!

Originally Posted by: Rob K 

Our ASHP and underfloor heating will be installed in three weeks, weather permitting.  Hoping it copes well, as it will be our only source of heating and hot water until the log stove is reinstalled and that won't be for a few weeks. 
Market Warsop, North Nottinghamshire.
Join the fun and banter of the monthly CET competition.
Matty H
02 December 2022 08:53:22

Agreed Brian. inevitable downgrades to come, but that run is up there with the most incredible I've seen on my 20 odd years on this forum.

 

Originally Posted by: Arbroath 1320 



I can think of many charts from 2010 and 2018 that were at least as good, no, way better (if you like cold, which I don't)
nsrobins
02 December 2022 09:17:26
Something tells me the UKM will jump off the fence with this afternoon's extended update 😉
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Arbroath 1320
02 December 2022 09:19:12

GEM is a blinder this morning and GFS also pretty darn good. 

ECM less impressive and loses the cold air from the south but still not bad for the time of year. 

My new heat pump may be getting a good workout before long - so far it hasn't had to deal with subzero temperatures!

Originally Posted by: Rob K 



Had one since 2017 Rob. The best tip I could give you, is not to install any elaborate programmes, i.e., increasing and reducing the temperature at different times of the day. Particularly if you have all underfloor heating like us. 

Select a temperature for the time of year and keep it constant 24/7. If the temperature drops quite low, e.g., if you turn the system off completely, it can take up to 24 hours for the house to heat up again. 
 
GGTTH
warrenb
02 December 2022 09:21:42

Something tells me the UKM will jump off the fence with this afternoon's extended update 😉

Originally Posted by: nsrobins 


I did note this morning on Twitter that a few of the more respected forecasters are now beginning to flag this up.
fairweather
02 December 2022 09:38:49

If I had a quid for every time on every run someone said game over or mostly rain I would be loaded . 

Originally Posted by: MBrothers 


........ and if I had a quid for every time it was mostly rain I'd be loaded !
S.Essex, 42m ASL
Whiteout
02 December 2022 09:43:31

Something tells me the UKM will jump off the fence with this afternoon's extended update 😉

Originally Posted by: nsrobins 



Ian F a bit more bullish this morning 😉
Home/Work - Dartmoor
240m/785 ft asl
fairweather
02 December 2022 09:51:25
[quote=Brian Gaze;1496828]Incredible GFS 00z run for cold weather fans. Probably one of the most impressive we've ever seen.

UserPostedImage[


/quote]

Has it changed? Looks like LP drawing up S.E'lies originating in N.Africa to me, as per DEW  "notably 980mb N Spain with not-so-cold SE-lies Tue 13th"
S.Essex, 42m ASL
fairweather
02 December 2022 09:56:02
Certainly going to be colder than most recent Decembers. One good thing solar modification will be minimal at this time of year, although N.Sea still relatively warm.
S.Essex, 42m ASL
westv
02 December 2022 10:12:17
Is it still on a knife edge and all to play for? More runs needed? 
At least it will be mild!
squish
02 December 2022 10:18:15
06z brings in the cold from the NE much quicker
D.E.W on Dartmoor. 300m asl
Arbroath 1320
02 December 2022 10:22:29

I can think of many charts from 2010 and 2018 that were at least as good, no, way better (if you like cold, which I don't)

Originally Posted by: Matty H 



As ever, I think there is a IMBY element to any run. The reason I think the 0z GFS op run was remarkable, is the prevalence of a cold E/NE/N flow from start to finish. Runs like that in Winter are very rare indeed.
GGTTH

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