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Arbroath 1320
03 December 2022 00:06:03

Let's face it, compared with this time yesterday it's not looking as great. Just as I start to nudge friends and family.

At least it's hugely interesting though. Seasonal though is great.

 

Originally Posted by: haghir22 



Agreed. 

On a more positive note, if you're a cold lover, the GFS 18z averages are much better than the 12z in FI, especially for the Southern contingent.
GGTTH
Gandalf The White
03 December 2022 00:09:30

Agreed. Outlook looks poor for most. I'll get flamed for saying it but that is the reality. 

Cool and dull is seasonal however, but probably not what most members want to see. 

Originally Posted by: Downpour 



You deserve to be criticised for ignoring the range of output which makes it clear that many options are still possible in a week from now and not acknowledging that the majority still favour an extended cold period.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


Gandalf The White
03 December 2022 00:12:53

Let's face it, compared with this time yesterday it's not looking as great. Just as I start to nudge friends and family.

At least it's hugely interesting though. Seasonal though is great.

 

Originally Posted by: haghir22 



Surely not!  That's the equivalent of arranging a barbecue in a normal warm spell in summer.  I've been caught out a few times when the charts have looked solid so I just give vague hints, heavily caveated.  

Which is what I am starting to do: turning quite a bit colder next week with a risk of something wintry falling.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


fairweather
03 December 2022 00:28:25

None at all, look from the window each day to see what going on outside.  Still miss the old days of newspapers, Ceefax, Teletext forecasts and TV forecasts.  Was always right most of the time.

Originally Posted by: Jiries 


Bear in mind these were generally three day forecasts at most ans so were inherently more accurate as they still are.
S.Essex, 42m ASL
fairweather
03 December 2022 00:43:01
We have the exact same conversations ad nauseum every winter. People being told off for saying it is going wrong whilst others remain optimistic. What anybody knows with one iota of common sense looking at the last ten years is that the best charts rarely materialise. That doesn't mean they can't or that that they won't. Just that the statistical odds are against them. We get charts at this distance two or three times most winters. And iit is fun looking at them and hoping nothing changes.  But the computers only predict the most likely outcome at that point in time and in a sense they are always right for that point in time otherwise they would never be right one hour from now. The only reason they appear to go "tlts up" is because the data has changed. Whilst modelling has improved for each day further away the prediction is the accuracy still diminishes exponentially. What I have never fully understood is why they have not been able to get that inaccuracy in both directions in winter. It does aseem that more go milder nearer the event than colder but even that is probably subjective based on what we hoped!
S.Essex, 42m ASL
UncleAlbert
03 December 2022 00:49:10

Surely not!  That's the equivalent of arranging a barbecue in a normal warm spell in summer.  I've been caught out a few times when the charts have looked solid so I just give vague hints, heavily caveated.  

Which is what I am starting to do: turning quite a bit colder next week with a risk of something wintry falling.

Originally Posted by: Gandalf The White 



​​​​​​As I always say to my family, I can only tell you when there is a potential for wintry weather in the next few weeks, in set ups such as we see
​​​​​currently, but there are times when I can say with near certainty that there will be nothing wintry over the same timescale ☹️
 
Arbroath 1320
03 December 2022 01:13:10

We have the exact same conversations ad nauseum every winter. People being told off for saying it is going wrong whilst others remain optimistic. What anybody knows with one iota of common sense looking at the last ten years is that the best charts rarely materialise. That doesn't mean they can't or that that they won't. Just that the statistical odds are against them. We get charts at this distance two or three times most winters. And iit is fun looking at them and hoping nothing changes.  But the computers only predict the most likely outcome at that point in time and in a sense they are always right for that point in time otherwise they would never be right one hour from now. The only reason they appear to go "tlts up" is because the data has changed. Whilst modelling has improved for each day further away the prediction is the accuracy still diminishes exponentially. What I have never fully understood is why they have not been able to get that inaccuracy in both directions in winter. It does aseem that more go milder nearer the event than colder but even that is probably subjective based on what we hoped!

Originally Posted by: fairweather 



Good post.

There is definitely a subsequent, milder correction when models initially predict a cold outbreak, in this part of the World at least. 

I would love to know the answer to your question as to why. I suspect it is to do with human intervention and data inputs to the model closer to the event.

Incidentally, I'm not sure that today's model output is nailed on. A Westward progression of a Scandi trough to the Mid-atlantic is not something we see too often. I think the trough will be corrected Eastwards in the next few runs, as the GFS 18z supports. 
GGTTH
CreweCold
03 December 2022 02:30:15
Funnily enough the ECM is known to over-amplify and it's overamplification that is the root cause of that op run tonight. HP goes too far N too quickly and allows the cold trough to cut across to our N, letting the Atlantic back in.

This is one instance where we want over-amplification bias to be a key component to the output it has churned out.

EDIT: its 18z control run backtracked slightly towards the UKMO and GFS
https://modeles3.meteociel.fr/modeles/gens/ecmwf/runs/2022120218/gensnh-0-1-144.png 

Crewe, Cheshire
55 metres above sea level
Rob K
03 December 2022 06:09:42
0Z GEFS in the short term show a much tighter clustering of cold with very few milder options now. 

UKMO is cold, and GEM is just a bit bobkers synoptically. All eyes on ECM...
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
Tim A
03 December 2022 06:27:27
ECM looks fine at 120hours with good cold getting South, more like UKMO than the messier GFS 
​​I prefer the GFS as messy means more potential for snow opportunities.

On the subject of telling family etc , definitely won't be doing this time as so much inconsistency re exact wind directions and what surface conditions will be like.  It could end up being dry and sunny in the most part which would actually be an improvement on the last week's weather of 3c and fog. Then again it could be snowy if there are disturbances.  
Tim
NW Leeds
187m asl

 My PWS 
Jiries
03 December 2022 06:46:33

ECM looks fine at 120hours with good cold getting South, more like UKMO than the messier GFS 
​​I prefer the GFS as messy means more potential for snow opportunities.

On the subject of telling family etc , definitely won't be doing this time as so much inconsistency re exact wind directions and what surface conditions will be like.  It could end up being dry and sunny in the most part which would actually be an improvement on the last week's weather of 3c and fog. Then again it could be snowy if there are disturbances.  

Originally Posted by: Tim A 



Yes need this nasty HP to go away as it make heating costs too high last few days due to nasty fog and clouds make house easily cold quicker than zonal, northerly, sunny frosty days that all those bring more sun input so heating only need short time in morning and evening than now on and off.  
nsrobins
03 December 2022 06:56:57

0Z GEFS in the short term show a much tighter clustering of cold with very few milder options now. 

UKMO is cold, and GEM is just a bit bobkers synoptically. All eyes on ECM...

Originally Posted by: Rob K 



The 00Z EC compared to yesterdays 12Z is synoptically similar but because of a few hundred miles difference in where the mean trough settles chalk and cheese in terms of conditions, particularly for the south. 
There will be much more noise in the media about next week today as the chances of a protracted cold spell continue to increase.
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Ally Pally Snowman
03 December 2022 06:58:09
Much better ECM this morning.  Decent output all round. I'd prefer 850s a couple of degrees lower but beggars can't be choosers.
 
Bishop's Stortford 85m ASL.
White Meadows
03 December 2022 07:00:34
ECM back to looking more favourable for coldies this morning. 
Lots of flip flopping with wild & mild outliers to come still I'm sure. 
ballamar
03 December 2022 07:17:09
It's never going to be as great as a deep easterly this set up for the southern contingent near the coast, but the outlook for December is much better than many. Surprise snowfalls are always a possibility depending when precipitation falls, intensity and evaporative cooling. If we get slack winds our own cold pool is very possible and that would bugger up a lot of forecasts. Enjoy the potential and if it does snow where you are enjoy it and not look for a breakdown in the model output. Decent output today
DEW
  • DEW
  • Advanced Member
03 December 2022 07:28:24
Query; does the MetO have a default option in which, if they're uncertain, they just put down a constant temp and unrelieved cloud? It looks like that here through to Tuesday; but the same forecast applied yesterday and we had a really nic sunny afternoon. It's happened before.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
DEW
  • DEW
  • Advanced Member
03 December 2022 08:05:58
WX temps looking better for coldies than was the case late yesterday. In week 2, the 0C isotherm now well west into France and an area covering half of Britain too, compared with cold but simply below average in week 1. At the same time, it has become much milder N of the Caspian and Black Seas. Pptn on Atlantic coasts and through W & C Med in week 1 shifts to become a broad band from N Africa through Balkans to W Russia in week 2, Briatin and N Atlantic looking dry-ish.

GFS Op - Ridge of HP extending SW to Britain rotating N-wards towards Iceland by Mon 5th while pressure drops over Britain and Scandinavia  while E-lies develop. Eventually LP well established  over Scandinavia and/or W Russia with trough extending SW-wards over Britain. The main centres in this trough shift around a bit (e.g. Wed 7th Finland 1005 mb to 990 mb Canaries, Sat 10th 1000 mb N Norway to 995 mb Holland, 1005 mb White Sea to 1000 mb France Tue 13th) but the net effect is to promote cold air from the NE to cover Britain throughout. Then HP develops over Scotland 1035mb Fri 16th with E-lies starting from an LP over Italy so less cold air to finish.

ECM - slower by a day or so to develop the NE-lies and the area of LP does not extend so far E into Russia, but the pressure pattern is generallly similar and in the last chart Tue 13th 1000 mb S Norway links to 990mb France with a more N-ly airflow, just as cold.

GEFS - mean temp below seasonal norm, coldest around Mon 12th (a couple of days earlier for Scotland) at about 7C below norm with good agreement between ens members after which some runs break ranks and start rising above norm. Occasional bursts of pptn in S & W, from Sat 10th, more general but smaller amounts in N & E

Various snow risk maps show bands of snowfall moving S from N Scotland to the Channel Coast Fri/Sat 9th/10th and again Tue/Wed 13th/14th, but not looking cold enough for prolonged cover except on hills.
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Hippydave
03 December 2022 08:15:49
So, ECM op moves towards the GFS/UKMO op position and draws down colder air countrwide and doesn't overdevelop the LPs and push it all away. 

Not surprising given it's own ens suite*, the GFS and UKMO output but a welcome movement given any dissenting charts from one of the main 3 models isn't a great sign. 

GFS and UKMO op both remain good if it's colder weather you're after and GEM is decent too. 

Progged daytime temps IMBY for the ECM run are pretty chilly from and including the 7th ->2.4c, 0.9c, 1c, 2.7c, 1.3c, 0.4c. 

*Ens wise it's fairly similiar to yesterday I think, with 850s generally grouped around -3 to -7, with increasing milder runs as you head deeper in to FI. There's very few runs that hit -10 so not a deep freeze but as shown by the progged temps IMBY given the lowish pressure and chilly uppers, along with low solar input, it's still a cold setup.

 
Home: Tunbridge Wells
Work: Tonbridge
Rob K
03 December 2022 08:27:27

Query; does the MetO have a default option in which, if they're uncertain, they just put down a constant temp and unrelieved cloud? It looks like that here through to Tuesday; but the same forecast applied yesterday and we had a really nic sunny afternoon. It's happened before.

Originally Posted by: DEW 


I think it's more the inherent uncertainty with high pressure conditions in winter as you can never really tell where the cloud will break and where it will hang around all day, which at this time of the year makes the difference between 3-4C and dank murkiness all day and 7-8C and decent sunny spells. 
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
marting
03 December 2022 08:32:24
The ECM op this morning does a complete reversal and end up at the cold end of its ensembles, but still some of its ensembles showing last nights run. One to watch for later (more runs needed 😂) However pretty cold runs all round continue and the detail will follow. 
Finally had a frost here this morning, it's arrived!
Martin
Martin
Greasby, Wirral.
Jiries
03 December 2022 08:35:47

Query; does the MetO have a default option in which, if they're uncertain, they just put down a constant temp and unrelieved cloud? It looks like that here through to Tuesday; but the same forecast applied yesterday and we had a really nic sunny afternoon. It's happened before.

Originally Posted by: DEW 



On apps yesterday put rain but nothing happen then this morning cloud and rain but to my surprise is sunny outside.  That why I miss the old days forecasting days. Showing snow next week at 2C and -3 at night on Thursday and Friday.
Whether Idle
03 December 2022 08:55:01
Good morning.  Ive taken an extended sabattical from the MO thread for longer than I can remember, but have kept an eye on the charts of late as the prospect of some cooler than average weather during the bleak mid-winter is a tantalising prospect.  Theres no better time in insolation terms to get something seasonal on the ground and keep it there; however, the counter balance to that is the theraml lag with SSTs still being in double digits across much of our coastal waters - making an offshore wind an important consideration to be factored in for coasteers.

My underlying concern is the background warming in the Arctic areas mean the source air is not as frigid as in times past, with the connected risk that fabulous old school synoptics churned out by the models are rendered 'false prophets' by the attendant modern day upper temperature profiles. In a sense we can "test" the effect on our prospects for wintriness that the warming in the Arctic is having, with these synpotics. This holds a degree of fascination for me. 

I would like nothing more than to see Christmas card like scenes countrywide as we hit mid December with a long sea track Polar Continental doing its thing.  There are suggestions in the FI output that as we move towards the middle of the month (an age away in forecasting terms) that the Holy Grail of synoptics could provide an early Christmas present for some.  Time will tell, but my interest has certainly been piqued though I remain deeply sceptical of any particular outcome.  Interesting times.

 
Dover, 5m asl. Half a mile from the south coast.
doctormog
03 December 2022 09:08:27

The ECM op this morning does a complete reversal and end up at the cold end of its ensembles, but still some of its ensembles showing last nights run. One to watch for later (more runs needed 😂) However pretty cold runs all round continue and the detail will follow. 
Finally had a frost here this morning, it's arrived!
Martin

Originally Posted by: marting 



I think generally the ECM and GFS ensemble suites have been remarkably consistent for days now. The details and tracks of the Lows have caused quite a few changes in the modelled "on the ground" conditions. It is all very interesting in terms of potential and indeed longevity. A few more days should give a bit more clarity:
  • Will proper cold (a few degrees below average) reach us? (Probably)
  • Will it be cold enough for snow? (Probably at times at least, but more likely for inland or higher areas given the time of year - see WI's point)
  • Will there be any precipitation? (Likely in "the usual places" for a northerly but also likely when any low pressure systems undercut). The caveat to both is that the precipitation may not be snow.
  • How long will it last? (Given the ensemble data several days of below average temperatures are likely. This could extend for much longer but as yesterday's 12z ECM op run showed it could be cut off relatively quickly.)


The Beast from the East
03 December 2022 09:15:31

Good morning.  Ive taken an extended sabattical from the MO thread for longer than I can remember, but have kept an eye on the charts of late as the prospect of some cooler than average weather during the bleak mid-winter is a tantalising prospect.  Theres no better time in insolation terms to get something seasonal on the ground and keep it there; however, the counter balance to that is the theraml lag with SSTs still being in double digits across much of our coastal waters - making an offshore wind an important consideration to be factored in for coasteers.

My underlying concern is the background warming in the Arctic areas mean the source air is not as frigid as in times past, with the connected risk that fabulous old school synoptics churned out by the models are rendered 'false prophets' by the attendant modern day upper temperature profiles. In a sense we can "test" the effect on our prospects for wintriness that the warming in the Arctic is having, with these synpotics. This holds a degree of fascination for me. 

I would like nothing more than to see Christmas card like scenes countrywide as we hit mid December with a long sea track Polar Continental doing its thing.  There are suggestions in the FI output that as we move towards the middle of the month (an age away in forecasting terms) that the Holy Grail of synoptics could provide an early Christmas present for some.  Time will tell, but my interest has certainly been piqued though I remain deeply sceptical of any particular outcome.  Interesting times.

 

Originally Posted by: Whether Idle 



Good to have you back. This place is a lot quieter than years gone by and we seem to have lost the likes of Steve Murr and Ian Brown.  I'm not expecting any snow down here especially from the northerly but the phasing of the trough look potentially interesting later in the week though could easily end up wet and cold. But before that we could have some nasty frosts as we lose the easterly and the cloud, so national grid better be up to shape!
"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
Brian Gaze
03 December 2022 09:21:59

Not sure what's wrong with the Outlook Model's page, but UK Met Office keeps giving an Oops! Page not found error

https://www.theweatheroutlook.com/twodata/datmrfcompare.aspx 

https://www.theweatheroutlook.com/404_two.aspx?aspxerrorpath=/twodata/ukmet.aspx 

Originally Posted by: Gavin D 



Should be ok now:

https://www.theweatheroutlook.com/twodata/datmrfcompare.aspx 

The UK Met links were pointing to the old thinned grid (the free version) plots which have now been replaced with the full version.
Brian Gaze
Berkhamsted
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