theweatheroutlook

Remove ads from site

Gandalf The White
16 November 2023 21:12:31

that may end up being true that high pressure builds more to the South as we get to the Winter, however is it not true that the Jetstream has been tracking much further south than normal recently since around mid-October, which would therefore suggest that high pressure to the South of us has been weaker and or further south than normal recently, which also explains all these storms that have often affected places further south than normal?

Originally Posted by: Taylor1740 



Yes, the jet stream has been further south, but that doesn’t alter the evidence of a slow but steady increase in heights to our south over recent decades. It’s like the difference between weather and climate.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


Rob K
16 November 2023 22:17:04

Indeed. The impressive thing was how well the snow lasted through the following days. In some ways I thought it was better locally than the 2010 event.
Anyway, GFS is still not without interest this afternoon, but as usual it is heights to the south which ruin things. This really is the bane of the "modern era" as far as cold weather in west Europe is concerned. People can work themselves into all sorts of contortions to produce complicated explanations of why X, Y or Z in some far flung part of the world will lead to cold weather in the UK. However, ignore the basics at your peril - the high pressure belt to the south is steadily extending northwards.

UserPostedImage

 

Originally Posted by: Brian Gaze 



if it was simply a case of high pressure to the south then Eastern Europe would be similarly affected. But they still get plenty of snow. 
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
Taylor1740
16 November 2023 22:34:04

Yes, the jet stream has been further south, but that doesn’t alter the evidence of a slow but steady increase in heights to our south over recent decades. It’s like the difference between weather and climate.

Originally Posted by: Gandalf The White 


perhaps so but in regards to weather forecasting surely you would look more at recent trends and the fact that the Jetstream has been further south than usual recently. I also haven't yet seen that much evidence in the modelling of that dreaded high pressure to the South pattern becoming established apart from the odd model run showing this that Brian has posted.

I'm sure of course that by 1 December it will have flipped to that doomed pattern of high pressure to the South and you will say "I told you so."
NW Leeds - 150m amsl
Brian Gaze
16 November 2023 22:37:23

Yes, it was Brian, as I mentioned this morning in my post above.

As you say, the odds are steadily worsening.  It doesn’t mean it can’t happen but makes it more difficult.

Originally Posted by: Gandalf The White 



This is the chart I posted last autumn.

UserPostedImage
Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
Gandalf The White
16 November 2023 23:42:30

perhaps so but in regards to weather forecasting surely you would look more at recent trends and the fact that the Jetstream has been further south than usual recently. I also haven't yet seen that much evidence in the modelling of that dreaded high pressure to the South pattern becoming established apart from the odd model run showing this that Brian has posted.

I'm sure of course that by 1 December it will have flipped to that doomed pattern of high pressure to the South and you will say "I told you so."

Originally Posted by: Taylor1740 



Well, I think the long-term trend is clear. Brian has reposted the chart and it shows an increase of about 3mb over my lifetime in the far south.  Of course there will be some oscillations during that time but the long term trend is pretty clear.

As I said, the long term trend doesn’t mean we can’t get periods of southerly tracking jets and potential cold weather, it just makes the odds longer.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


+1
ballamar
17 November 2023 07:51:10

if it was simply a case of high pressure to the south then Eastern Europe would be similarly affected. But they still get plenty of snow. 

Originally Posted by: Rob K 



Hate saying this but that chart would infer more warm southerly flows over Greece taken at face value! Lots of opportunity for cold still but the trend is there to see. 
doctormog
17 November 2023 07:57:55
There seems to be quite a strong signal for colder conditions from the north for the last week of the month on the GFS 00z ensemble set this morning (excluding the op run!): 

UserPostedImage 
Aberdeen
Current conditions (personal WS) 
DEW
  • DEW
  • Advanced Member
17 November 2023 08:24:03
WX charts revive the idea of a major cooling for Europe over the next two weeks. For week 1 most of Europe (now incl Spain) is near norm though rather colder to the NE. In week 2 the freezing area currently over Russia extends SW-ward to the Balkans, Switzerland and even a touch in S France. The near continent is also noticeably colder but Britain has little change. Rain in week 1 stretches in a band from Britain to the Black Sea, heavy at the E end of this; in week 2 it is concentrated over the Aegean while in a change from yesterday the far west from Britain down to Spain becomes dry.

GFS OP - over the weekend an Atlantic LP circulates around the northern perimeter of Britain (FAX shows fronts across most of the country on Sat) ending up Tue 21st 1005mb Italy. For the next week to Tue 28th HP is parked W of Ireland with winds from the N running down the N Sea, particularly strong on Fri 24th as LP in the Baltic deepens. The HP then moves to the east and is centred 1035mb Wales Fri 1st while the Baltic LP declines (moving S to affect Greece) and air from the Atlantic moves across Britain.

ECM - the weekend LP above takes in E Britain as it moves away, rather than staying in the N Sea. The HP begins to grow from Tue 28th but stays further SW so on Fri 24th/Sat 25th all Britain has NW-ly gales. The HP does not re-establish and by Fri 1st LP from Greenland is 975mb Rockall and threatening a spell of Polar Maritime  air.

GEFS - Rain and milder for the weekend then dry into December with the possibility of a little rain then. Ens members agree on another mild spell near Fri 24th (note difference from ECM) after which most go cold,  mean slowly recovering to near norm but with decreasing agreement. Somewhat milder and later wetter in the far SW; for many places in Britain you can cherry pick at least one ens member with temps at -10C from Fri 24th onwards! Inverness snow row figures 25/33 around the 24th.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
+6
Brian Gaze
17 November 2023 09:12:16
Two points to make:

1) The chart shows the trend through the meteorological winter period as a whole

2) It is often passed off as fact that "Greece is taking the UK's cold weather", but does the evidence support that? Have average winter temperatures in Greece decreased in the last 50 years? (I genuinely don't know) 
Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
Rob K
17 November 2023 10:20:56

Hate saying this but that chart would infer more warm southerly flows over Greece taken at face value! Lots of opportunity for cold still but the trend is there to see. 

Originally Posted by: ballamar 


That's exactly what I mean. Yet from what I can see the Balkans seem to have got snowier in recent years. I suppose it could be that increased moisture from the south is leading to more precipitation, and the increased warmth not (yet) tipping the temperature high enough to prevent snow?
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
17 November 2023 10:26:06

Two points to make:

1) The chart shows the trend through the meteorological winter period as a whole

2) It is often passed off as fact that "Greece is taking the UK's cold weather", but does the evidence support that? Have average winter temperatures in Greece decreased in the last 50 years? (I genuinely don't know) 

Originally Posted by: Brian Gaze 



I found this map:

UserPostedImage

https://www.eea.europa.eu/data-and-maps/figures/observed-changes-in-warm-spells-and-frost-days-indices-1976-2006/map-5-6-climate-change-2008-warm-spells.eps/image_large 

Note that the scale was apparently designed by a total idiot, as the blue colours on the right-hand map indicate fewer frost days!

So Greece gets less cold weather, but apparently western Turkey (and Spain) gets more.


Anyway back to today's models, 6Z GFS brings back more of a proper northerly in a week's time.
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
dagspot
17 November 2023 17:29:39
Fawksie ‘Turning colder with snow for Scotland towards end of next week’ 
Neilston 600ft ASL
doctormog
17 November 2023 17:48:31

Fawksie ‘Turning colder with snow for Scotland towards end of next week’ 

Originally Posted by: dagspot 



Yes that ties in with the recent trend in the charts although it may only be for prone locations (perhaps with a bit of altitude). Having said that the signal does seem to have strengthened over the last couple of days.

This chart is from the 12z GEFS ensemble data: https://modeles16.meteociel.fr/modeles/gensp/run/gensprobuk-26-204.png?12  
Aberdeen
Current conditions (personal WS) 
ballamar
17 November 2023 21:05:17
Bit of a rubbish run for the cold northerly!
BJBlake
18 November 2023 00:25:32
Latest runs prolonging the northerly plunge and delaying the toppler. Might be enough for a taste of proper winter. I think the seas are still too warm for wintriness away from high ground.

It’s just so warm these days. I was looking back at photos of my childhood in the 60s and 70s, and leaves were off the trees by bonfire night. Just a few brown oak leaves left. Some of these were frosty - down to -5 on one occasion, and lots more quiet spells of fog and frost - with day temps reaching 5 or 6 degrees. 

Such a contrast to now - leaves still on the trees - November 17th, oaks still green. The October 87 gale was devastating because leaves were still on the trees, but the risk is far greater for gales into November, and now days, leaves remain on the trees into December.
We’ve over-burned fossil fuels and will burn the world faster for it.
Brecklands, South Norfolk 28m ASL
+1
David M Porter
18 November 2023 00:46:15

Latest runs prolonging the northerly plunge and delaying the toppler. Might be enough for a taste of proper winter. I think the seas are still too warm for wintriness away from high ground.

It’s just so warm these days. I was looking back at photos of my childhood in the 60s and 70s, and leaves were off the trees by bonfire night. Just a few brown oak leaves left. Some of these were frosty - down to -5 on one occasion, and lots more quiet spells of fog and frost - with day temps reaching 5 or 6 degrees. 

Such a contrast to now - leaves still on the trees - November 17th, oaks still green. The October 87 gale was devastating because leaves were still on the trees, but the risk is far greater for gales into November, and now days, leaves remain on the trees into December.
We’ve over-burned fossil fuels and will burn the world faster for it.

Originally Posted by: BJBlake 



Think it depends on where one is wrt how many leaves are still on the trees. In the second half of October, there was a big clearance of leaves off the trees in my part of the world and there are only a few leaves still clinging to some trees now. I can't say that the same period in October was all that warm either, certainly much less so compared to September and the first week or so of October.
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
18 November 2023 06:47:46
It's eye-candy season - some of this morning's GEFS members are superb, if you're in the south and after cold weather that is!

https://www.meteociel.fr/modeles/gefs_cartes.php?ech=300&code=21&mode=0&carte=0&ext=0 

is just one example. Plenty more of that to come, I'm sure, but at that range I'm certainly not going to do more than slightly raise an eyebrow.

It all depends on how that ridge to the west behaves... and there's simply no way of knowing just yet.
Leysdown, north Kent
ballamar
18 November 2023 07:23:37

It's eye-candy season - some of this morning's GEFS members are superb, if you're in the south and after cold weather that is!

https://www.meteociel.fr/modeles/gefs_cartes.php?ech=300&code=21&mode=0&carte=0&ext=0 

is just one example. Plenty more of that to come, I'm sure, but at that range I'm certainly not going to do more than slightly raise an eyebrow.

It all depends on how that ridge to the west behaves... and there's simply no way of knowing just yet.

Originally Posted by: Retron 



if nothing else great to see the cold chart potential! Probably a rogue run but who knows 
White Meadows
18 November 2023 07:59:55

if nothing else great to see the cold chart potential! Probably a rogue run but who knows 

Originally Posted by: ballamar 



Not exactly a rogue run in the grand scheme of things- very much a clear and consistent trend for a shift to cold by Sunday 26th:

https://www.wetterzentrale.de/en/show_diagrams.php?geoid=49069&model=gfs&var=202&run=0&lid=ENS&bw=1 

Most likely from a north/ north easterly quarter at least to begin with.

No sniff of the like on Exeter’s narrative although they are very cagey these days about frightening nanny off her rocker. This may well fall in line later next week if this continues. 

 
DEW
  • DEW
  • Advanced Member
18 November 2023 08:25:28
WX temp chart continuing the features shown yesterday. Week 1 W Europe near norm but with colder air massing to the NE. Week 2 that mas of cold air floods across W Europe with freezing weather down to the Adriatic, Germany, even S France. Britain and nearby continental coast stay above freezing but still colder than shown yesterday. Rain (?snow) principally in a horseshoe down the N Sea to Italy and and curving back through the Aegean up to the Urals. In week 2 the eastern arm of this becomes more pronounced; Briain stays damp rather than wet.

GFS Op - the current LP perambulating around the N of Britain and then on S-wards to the Adriatic by Wed 22nd, though doing so closer the the E coast as it passes by. HP then establishes just W or SW of Britain through to Mon Dec 4th. The actual position determines the source for air for Britain; N/NE-ly and rather cold for England Mon 27th but not lasting as the HP drops S-wards and milder air spreads across Scotland from the west.

ECM - similar to GFS until Mon 27th when the HP instead of withdrawing strengthens to the east, blocking ny NE-lies and substituting SW-lies for W Britain.

GEFS - cooling slowly, a mild burst around Fri 24th, the abruptly colder with mean 3-5C below norm through to Mon 4th and the control run especially much colder than this. In the S, mostly dry for a week this, rain in many runs later; in the N esp NW small amounts of rain at various times in various runs but snow likely in the Highlands at times esp near Mon 27th.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
+6
BJBlake
18 November 2023 08:36:46
Definite upgrade for cold weather fans this morning, with extended time frame, deeper cold air transference. This extended length helps to embed the cold, cool down warm ground and may start to push the first wintriness of winter south.

Living, not too far from Santon Downham, the sandy soils will cool and some decent festive frosts might be on the cards, after the winds begin to slacken. All a great sight to behold compared to the relentless west to east flow of late, even if the rain is good for the aquifers and reservoirs. I love a bit of festive cheer in advent to get me in the mood...we all need a bit of joy this year!!
Brecklands, South Norfolk 28m ASL
+3
Ally Pally Snowman
18 November 2023 09:06:14
GFS is normally the first to pick up a pattern change. So let's see if the ECM and others follow.  At the very least it would be nice to get some frosty dry weather.
 
Bishop's Stortford 85m ASL.
+1
David M Porter
18 November 2023 12:56:57

Definite upgrade for cold weather fans this morning, with extended time frame, deeper cold air transference. This extended length helps to embed the cold, cool down warm ground and may start to push the first wintriness of winter south.

Living, not too far from Santon Downham, the sandy soils will cool and some decent festive frosts might be on the cards, after the winds begin to slacken. All a great sight to behold compared to the relentless west to east flow of late, even if the rain is good for the aquifers and reservoirs. I love a bit of festive cheer in advent to get me in the mood...we all need a bit of joy this year!!

Originally Posted by: BJBlake 



Hear hear! 👍👍👍
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
White Meadows
18 November 2023 12:58:56
Increased support for 2 blasts of cold on the 06z

the first next weekend, then slightly less cold followed by the chance of something special come December.
 
fairweather
18 November 2023 16:18:41

Latest runs prolonging the northerly plunge and delaying the toppler. Might be enough for a taste of proper winter. I think the seas are still too warm for wintriness away from high ground.

It’s just so warm these days. I was looking back at photos of my childhood in the 60s and 70s, and leaves were off the trees by bonfire night. Just a few brown oak leaves left. Some of these were frosty - down to -5 on one occasion, and lots more quiet spells of fog and frost - with day temps reaching 5 or 6 degrees. 

Such a contrast to now - leaves still on the trees - November 17th, oaks still green. The October 87 gale was devastating because leaves were still on the trees, but the risk is far greater for gales into November, and now days, leaves remain on the trees into December.
We’ve over-burned fossil fuels and will burn the world faster for it.

Originally Posted by: BJBlake 


Yes. Was commenting on the Autumn gold on the trees just coming to a peak and the first leaves falling from our Silver Birch in earnest. Autumn is about two - three weeks later which is a lot. I also have stood frozen with my kids at past bonfire night firework displays, on one occasion with snow on the ground and others with below zero temperatures. We've not had an air frost here yet and often don't till December these days. 
S.Essex, 42m ASL

Remove ads from site

Ads