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Model Output Discussion - Snow for some, but what else is in store?


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Posted
  • Location: Locksbottom, NW Kent 92m asl(310ft)
  • Weather Preferences: Warm summers but not too hot and colder winters with frost and snow
  • Location: Locksbottom, NW Kent 92m asl(310ft)
11 minutes ago, Tim Bland said:

ECM shifts the centre of the low midweek from North of the Uk to Northern England. Quite a big shift south, could go even further south 18z Vs 00z below 

7B9EF3D8-CAD7-4ADD-BE3B-A0FAAEE81388.jpeg

686C1964-742C-44DC-B9F5-27C72C392AC7.jpeg

Second chart is interesting.Ideally would like centre of low 50-75 miles further east so we would drag in cooler uppers from north but it wouldn’t take much on grand scheme of things for that to happen.that chart for 21st so just about in timescale of effects of SSW?If nothing else fascinating model watching this winter which has already proved better in terms of snow than last 2 winters and excluding BFTE in 2018 I would suggest since 2013!!I even have snow falling now in nw Kent although it won’t amount to anything(still nice to see though)

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Posted
  • Location: Aberporth S W Wales
  • Location: Aberporth S W Wales

ECM the best of the bunch in the reliable (whatever that is!?) Low further south and better alignment at 192 of the inevitable Atlantic system...just looking at the 850's which are better this morning, but cast your eye to Russia and the temperature gradient there! Goes from +5 to -30 in what looks like a few hundred miles. The other striking factor looking at this chart is the wall the easterly north of the UK provides to the real cold preventing it from heading south ,  

ECMOPEU00_192_2.png

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Posted
  • Location: 50/50 Greece/Germany
  • Weather Preferences: Cold winters, hot summers
  • Location: 50/50 Greece/Germany
19 minutes ago, wolvesfan said:

Is it possible that the affects of the ssw will be felt in a couple of weeks?,and not immediately. 
If so then the charts we are viewing aren’t a direct tropospheric response to the ssw,but standard winter weather. 
Maybe fi in this instance should be taken more seriously?   

Yes, could be that effects will somehow delay. Every SSWE is different, it’s overall a chaotic system, small butterfly effects can cause huge differences in oncoming outputs. Deterministic weather models are just trying to organise this chaos with mathematics and statistics, they do somehow good for 3,4 days but then the quality  drops fast, with an unpredictable SSWE outcome even more, one can see this in the verification graphs  

some see the charts and forget that they are not flat, the atmosphere is 3D with a lot of fluxes, raises drops of air masses etc

for example a strong winter storm low is like a mixer, it Quirles the atmosphere with so much energy that it often changes patterns to a total different outcome as predicted that’s why I’m saying that they can act like dooropeners 

so, whatever the models are trying to forecast, it can be a 180* turnaround next week without any signs of today 

wait, lean back and keep the faith

 

Edited by Vikos
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Posted
  • Location: Penrith Cumbria
  • Weather Preferences: Cold, snowy winters and warm sunny summers
  • Location: Penrith Cumbria

I do like the ECM at 240 not for the actual surface conditions although it would be interesting in Scotland but for the reverse wind flow easterly to our north which could so easily shift south.

Look at this chart for late December 1978, looks so much like the ECM (although ECM 240 looks more favourable) yet 3 days after that December 78 chart southern Britain was swept by a severe blizzard.

Just saying.....

Andy
 

 

0FC30265-B5A5-4CA1-B1AB-66629969528D.jpeg

907CC56C-148D-4E5F-8028-C9C34ABBDF0D.jpeg

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Posted
  • Location: Croydon. South London. 161 ft asl
  • Weather Preferences: Thunderstorms, snow, warm sunny days.
  • Location: Croydon. South London. 161 ft asl

There appears to be signs of something colder from the N/NE at the end of Jan - early Feb when you look at both the GFS  from the NH view it doesn't look too bad.

image.thumb.png.d68938c54f06b2639edba36401d3e7c9.png image.thumb.png.ad38b6c5309bf689f4d306fac182b2bf.png

The GEM also looks like maybe pressure starting to our N/NE.

image.thumb.png.4fd1e61c26510e1acc4de8f11779f7b3.png

 

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Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth
5 minutes ago, Vikos said:

Yes, could be that effects will somehow delay. Every SSWE is different, it’s overall a chaotic system, small butterfly effects can cause huge differences in oncoming outputs. Deterministic weather models are just trying to organise this chaos with mathematics and statistics, they do somehow good for 3,4 days but then the quality  drops fast, with an unpredictable SSWE outcome even more, one can see this in the verification graphs  

some see the charts and forget that they are not flat, the atmosphere is 3D with a lot of fluxes, raises drops of air masses etc

so, whatever the models are trying to forecast, it can be a 180* turnaround next week without any signs of today 

wait, lean back and keep the faith

 

6th jan, day after the ssw ECM t240. Today’s ecm. Considering all that’s going on not a bad a guess at nhp. At this time I would say that ssw is modelled. For some it’s been fun and for others it’s been too far north. Still plenty of time left for a disorganised nhp to produce for all. However at this time it’s not obvious how or will it. As I say I’m talking uk as whole.

3DFAF82D-C831-4FD4-9A56-34911DA6B18D.png

962F0EAD-A770-4AA4-92E9-46B7E50234BF.png

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Posted
  • Location: STEVENAGE, HERTS (100M ASL)
  • Location: STEVENAGE, HERTS (100M ASL)
6 minutes ago, Penrith Snow said:

I do like the ECM at 240 not for the actual surface conditions although it would be interesting in Scotland but for the reverse wind flow easterly to our north which could so easily shift south.

Look at this chart for late December 1978, looks so much like the ECM (although ECM 240 looks more favourable) yet 3 days after that December 78 chart southern Britain was swept by a severe blizzard.

Just saying.....

Andy
 

 

0FC30265-B5A5-4CA1-B1AB-66629969528D.jpeg

907CC56C-148D-4E5F-8028-C9C34ABBDF0D.jpeg

Exactly! Small shifts will make a huge difference. It’s like a lot of people were saying..we have reverse zonality just to our north and this is likely an effect of the SSW. It’s fruitless hoping the models are all blind to the SSW and are going to suddenly flip ..all we need is a few adjustments to the current pattern - which is more than possible- and we will be in business for widespread Uk snow ⛄️ PS 1 inch and counting here ❄️⛄

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Posted
  • Location: Bournemouth
  • Weather Preferences: Dry mild or snow winter. Hot and humid summer.
  • Location: Bournemouth
9 minutes ago, Penrith Snow said:

I do like the ECM at 240 not for the actual surface conditions although it would be interesting in Scotland but for the reverse wind flow easterly to our north which could so easily shift south.

Look at this chart for late December 1978, looks so much like the ECM (although ECM 240 looks more favourable) yet 3 days after that December 78 chart southern Britain was swept by a severe blizzard.

Just saying.....

Andy
 

 

0FC30265-B5A5-4CA1-B1AB-66629969528D.jpeg

907CC56C-148D-4E5F-8028-C9C34ABBDF0D.jpeg

I would say they are very different and would be even more noticeable from a nhp.

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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

The next ten days look relatively predictable and the d10 gefs mean highlights the bigger picture:

713354036_gensnh-31-1-240(3).thumb.png.9c2553048c258be8eb236b9e59fdcd73.png995259751_gensnh-32-1-240(1).thumb.png.af9e26108a340b5833e7950f699159a6.png

The spread for the NH suggests any entropy is in the Pacific region. For the UK there is some spread as to the more zonal flow (Iberian wave -v- LP systems). Nothing that we could construe as game-changing.

By d12 the gefs are still telling different stories as to how the NH develops but for the UK solid support for a flatter flow:

21817910_gensnh-31-1-312(1).thumb.png.91e11d85e54fa2d857d7f2c71201c7ad.png 1273975302_graphe6_10000_310.85646057128906_149.03004455566406___(1).thumb.png.5f1f5a86dba62c0fde5e4bad7bfc669b.png

Nothing cold from a mean perspective, London (^^^) nominal snow risk, and with a westerly trait, rain the main weather phenomenon (IMBY). 

By d16 (JFF) the mean maybe heading back to a NW>SE flow, trough synoptic (low confidence):

gensnh-31-1-384.thumb.png.4b6c7f81417e854ac3810a5623d86154.png269613453_gensnh-31-0-384(1).thumb.png.c6cb1e32da1bde50da9664f9a0fdbcff.pnggensnh-32-1-384.thumb.png.b5d98c6ba12aef7e5f5456cc12d76259.png

The spread suggests the likelihood of a tPV chunk over Greenland, variation on the euro trough and any SSWE chaos on the other side of the NH. The 850's shows that the axis of cold remains unfavourable and we will need to rely on scraps of cold injected from compliant surface features.

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Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

I was reading about a recent warming trend in southern China and flooding rainfalls near the Yangtze River, what relevance that has would be the Siberian high that has been flooding cold air into larger portions of China may get nudged northwest by shifts there, and that could have a knock-on effect on the conjoined Russian high. It might take a week or two for any of that to reach the European zone. 

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Posted
  • Location: Irlam
  • Location: Irlam
44 minutes ago, Penrith Snow said:

I do like the ECM at 240 not for the actual surface conditions although it would be interesting in Scotland but for the reverse wind flow easterly to our north which could so easily shift south.

Look at this chart for late December 1978, looks so much like the ECM (although ECM 240 looks more favourable) yet 3 days after that December 78 chart southern Britain was swept by a severe blizzard.

Just saying.....

Andy
 

 

0FC30265-B5A5-4CA1-B1AB-66629969528D.jpeg

907CC56C-148D-4E5F-8028-C9C34ABBDF0D.jpeg

Maybe. Looking at the Glasgow 2m ECM temps suggest below average throughout and there is a large easterly component in those wind roses towards the end

render-gorax-blue-001-6fe5cac1a363ec1525

 

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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

The ecm, gem and gfs mean at d10 shows that there is a high certainty for how the pattern develops up to then and I am not expecting many big changes because of that strong unison:

61967643_EDH1-240(8).thumb.gif.c6e2822ff57214097652a3f1942ee97e.gif1686566688_gensnh-21-1-240(1).thumb.png.e45277463fa1c303fc50279f4e794b64.png1056811652_gensnh-31-1-240(4).thumb.png.23ef97f7dcb4ee38d5ddb5180ffcd24e.png

This would suggest that the strat>trop coupling has led us to this imprint, showing that there is no certainty from an SSWE of mid-latitude cold. Also, as this is one of the strongest events, a dichotomy as to strat -v- trop as to the expected effects. I would have thought that the initial response is what dictates the tPV damage, so if the current disruption is the solution, we may not expect further big changes, apart from a possible second warming? 

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Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire
1 hour ago, D.V.R said:

There appears to be signs of something colder from the N/NE at the end of Jan - early Feb when you look at both the GFS  from the NH view it doesn't look too bad.

image.thumb.png.d68938c54f06b2639edba36401d3e7c9.png image.thumb.png.ad38b6c5309bf689f4d306fac182b2bf.png

The GEM also looks like maybe pressure starting to our N/NE.

image.thumb.png.4fd1e61c26510e1acc4de8f11779f7b3.png

 

 

Stick within t144 time frame, we're struggling to get 4 days correct let alone 2 weeks, 

I know your trying pick a pattern so cudos, but honestly anyone that reads these charts correctly will understand its just a mathmatical equation based upon today, focus on 6 days and under at the very longest, 

I like the ECM, uppers a little colder, I'm sure by next wk things will start to look colder again, we want the artic high to push south, if this happens its bringing our chances of deep cold higher. The low pressure will sink south, so will the colder air 

Edited by Blessed Weather
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Posted
  • Location: Netherlands
  • Location: Netherlands
14 minutes ago, IDO said:

The ecm, gem and gfs mean at d10 shows that there is a high certainty for how the pattern develops up to then and I am not expecting many big changes because of that strong unison:

61967643_EDH1-240(8).thumb.gif.c6e2822ff57214097652a3f1942ee97e.gif1686566688_gensnh-21-1-240(1).thumb.png.e45277463fa1c303fc50279f4e794b64.png1056811652_gensnh-31-1-240(4).thumb.png.23ef97f7dcb4ee38d5ddb5180ffcd24e.png

This would suggest that the strat>trop coupling has led us to this imprint, showing that there is no certainty from an SSWE of mid-latitude cold. Also, as this is one of the strongest events, a dichotomy as to strat -v- trop as to the expected effects. I would have thought that the initial response is what dictates the tPV damage, so if the current disruption is the solution, we may not expect further big changes, apart from a possible second warming? 

Excellent post. We see that the pictures look alike. Seems to me, there is no chaos. The models can handle what's going on.

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Posted
  • Location: Aberporth S W Wales
  • Location: Aberporth S W Wales
26 minutes ago, IDO said:

The ecm, gem and gfs mean at d10 shows that there is a high certainty for how the pattern develops up to then and I am not expecting many big changes because of that strong unison:

61967643_EDH1-240(8).thumb.gif.c6e2822ff57214097652a3f1942ee97e.gif1686566688_gensnh-21-1-240(1).thumb.png.e45277463fa1c303fc50279f4e794b64.png1056811652_gensnh-31-1-240(4).thumb.png.23ef97f7dcb4ee38d5ddb5180ffcd24e.png

This would suggest that the strat>trop coupling has led us to this imprint, showing that there is no certainty from an SSWE of mid-latitude cold. Also, as this is one of the strongest events, a dichotomy as to strat -v- trop as to the expected effects. I would have thought that the initial response is what dictates the tPV damage, so if the current disruption is the solution, we may not expect further big changes, apart from a possible second warming? 

Fair point.There is alot of noise about FI being 120 hrs, probably because going much past this is painful viewing. If you look at all models, gfsp, control, ecm, ops that go out to day 10 there is actually good agreement, if anything the cold and Atlantic systems are trending north in that timeframe..     

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Posted
  • Location: Wyke regis overlooking Chesil beach.
  • Weather Preferences: Snowfall
  • Location: Wyke regis overlooking Chesil beach.

Avid coldie as I am. I have to admit that as so often happens that the cross model trend is for something that looked pretty good a while back to be nothing more than a three day colder than average spell. Biggest hope for me on the south coast is a small slider/runner although not holding out much hope in that regard.   Beyond the three day (not so ) wonder. I think we're looking end of Jan beginning of Feb for the next possibilities as some of the modelling toys with the idea of a Griceland high around then.

Other than that unless the short/ medium term trends flip then for the south at least it looks close but no cigar in this first round of ssw induced patterns.

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Posted
  • Location: Cwmbran. South East Wales 300ft ASL
  • Location: Cwmbran. South East Wales 300ft ASL
10 minutes ago, TEITS said:

Based on what I have seen of the model output these past few days I would like to make a few points.

1. Do not be surprised to see a slow shift to the south of the overall pattern over the next few days.

2. Keep an eye on any future snow events as low pressure moves across the UK. Very often we see these move S on successive runs. I have lost count of many snow events modelled for the N of England only to move that far S the precip does not even reach the S coast.

3. Even if the above does not occur in the reliable timeframe the overall trend from the models is to slowly push the PFJ further S.

Good to see you TEITS

Quick question with regards to those trends. Would they be trends you noticed in winters over the years with a Non SSW driven trop? Would the effects of this SSW have an effect on those trends?

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Posted
  • Location: Herne Bay Kent
  • Location: Herne Bay Kent
2 hours ago, wolvesfan said:

Is it possible that the affects of the SSW will be felt in a couple of weeks?and not immediately. 
If so then the charts we are viewing aren’t a direct tropospheric response to the SSW but standard winter weather. 
Maybe fi in this instance should be taken more seriously?  
Something noteworthy has surely got to materialise from this winter. 

Yes. Another weather enthusiast who feels the same. Things can take time to settle into a new pattern... Why should this time be any different?!  

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Posted
  • Location: Herne Bay Kent
  • Location: Herne Bay Kent
3 minutes ago, WINTRY WALES said:

Good to see you TEITS

Quick question with regards to those trends. Would they be trends you noticed in winters over the years with a Non SSW driven trop? Would the effects of this SSW have an effect on those trends?

Absolutely 

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Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

Subtlety, the main trough is being an increasingly hard time advancing on the UK fully in 9-10 days time. It’s trending slower and we see signs of further lows peeling away from it, keeping cold air involved across the UK - most likely the north of course but the south is kept in with a chance.

Maybe this trend will halt now, maybe not. Just something to keep in mind for the time being. Keeps me from sitting back and assuming there’s going to be nothing to watch out for past wind & rain in these parts (the far south).

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Posted
  • Location: Cambridge, UK
  • Weather Preferences: Summer > Spring > Winter > Autumn :-)
  • Location: Cambridge, UK
24 minutes ago, sebastiaan1973 said:

Sorry to say. Painful for me, as for most of you. No winter in the EC plume.

6002a336d717a.png

Sounds about right to me. Outlook is looking pretty poor on the whole barring some transient snow events. Certainly not very exciting in my view anyway.

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Posted
  • Location: 50/50 Greece/Germany
  • Weather Preferences: Cold winters, hot summers
  • Location: 50/50 Greece/Germany
1 hour ago, sebastiaan1973 said:

 Seems to me, there is no chaos. The models can handle what's going on.

Aha, so it seems, they can handle it?

14th 00z vs 16th 00z for 24-1-21

c3mvnuj8.gif

 

Now 25th in comparission today 00z / yesterdays 00z

dtxo3fff.gif

 

Or lets do it with a 10 days prognosis of 850is for today

6th Jan +10 days

h8p9q42s.gif

 

I hope you get my point...

Edited by Vikos
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