Model output discussion - The run up to Christmas

[Howie]

Just now, Frosty Winter said:

06z ensembles looking cold into the first week of January, certainly nothing notably milder is looking likely anytime soon. Averaging well below average from the 28th onwards with a few members turning very cold in the new year.

Day 10 mean is also fantastic!

And the mean is gradually sloping downwards as we head into January

[kold weather]

Some really snowy members out to 240hrs on the GFS ensembles, though no real confidence onb where any upper high sets itself up, which is a little concerning but that should sort itself out in the wash.

Pretty close to all runs are still cold at 240hrs, and a considerable number have snow events after the 30th December.

@mountain shadowoh it will be marginal I agree, to be fair in this country it rarely isn't. However I do disagree with you when you say there will be little snow away from Scottish mountains. I think there actually will be quite a considerable amount on the proviso we can get a decent active front across the country. If we do the odds for a 10-20cms type fall is fairly high for somewhere.

[MATTWOLVES 3]

There ain't much to add to the brilliant analysis on here already...the flow is becoming colder,the troughs are circulating cold air and wedges...the fun and games begin from around this Sunday..This should help take our minds of the current dire situation,and it may make it worse for some...but if it comes,and I think it will...let's have fun..ECM precipitation graphics look solid.

[WxHerts]

End of GFS 6z OP really reminded me of this from NYE 1978 lol.. more info on that here: https://www.netweather.tv/forum/topic/72097-snowstorm-of-dec-30th31st-1978/

 

[swfc]

Bit chaotic todayanyway good start to the day "I think" anyway things are ticking along nicely. Quite a bit of swinging on the models and looks to me fi has got a bit closer timescale wise? So enjoy and try and be nice, it is the festive season afterall

[snowice]

2 minutes ago, Frosty Winter said:

06z ensembles looking cold into the first week of January, certainly nothing notably milder is looking likely anytime soon. Averaging well below average from the 28th onwards with a few members turning very cold in the new year.

Day 10 mean is also fantastic!

 

3 minutes ago, Allseasons-si said:

There is always one...

anyway,the gefs mean out to day ten is still rock solid,infact,it's even better than the 00z

check this out...

 

Looks like Squidward sponge Bob.

[That ECM]

7 minutes ago, Frosty Winter said:

06z ensembles looking cold into the first week of January, certainly nothing notably milder is looking likely anytime soon. Averaging well below average from the 28th onwards with a few members turning very cold in the new year.

Day 10 mean is also fantastic!

Not one of the 30 above the red line from the 29th forwards.

[Matt H]

3 minutes ago, That ECM said:

Not one of the 30 above the red line from the 29th forwards.

I know, I had a look at the 06z from exactly a year ago and it really puts into perspective how much worse things could be at the moment. 

Fantastic model output this morning!

Edited December 23, 2020 by Frosty Winter

[Met4Cast]

Next weeks +EAMT event is starting to pique my interest, with further possibilities as we go into January. This should help to see a renewed surge of blocking in the Atlantic/Greenland area in early January, models will likely struggle to plot this so expect to see increasing swings within the extended outputs, and perhaps some nirvana looking outputs too..

Lots to be optimistic & excited about for January.

[Sweatyman]

9 minutes ago, MATTWOLVES said:

There ain't much to add to the brilliant analysis on here already...the flow is becoming colder,the troughs are circulating cold air and wedges...the fun and games begin from around this Sunday..This should help take our minds of the current dire situation,and it may make it worse for some...but if it comes,and I think it will...let's have fun..ECM precipitation graphics look solid.

Blimey I've come over all funny...

[Djdazzle]

Thinking in terms of Lotto:

At least our numbers are in the bag this year. Whether we will get lucky is yet to be decided. Last year, we were waiting for numbers that had already been drawn!

fascinatimg times!

[Man With Beard]

15 minutes ago, Allseasons-si said:

There is always one...

anyway,the gefs mean out to day ten is still rock solid,infact,it's even better than the 00z

check this out...

 

Carbon copy almost of ECM mean - that's good

[Howie]

2 minutes ago, Met4Cast said:

Next weeks +EAMT event is starting to pique my interest, with further possibilities as we go into January. This should help to see a renewed surge of blocking in the Atlantic/Greenland area in early January, models will likely struggle to plot this so expect to see increasing swings within the extended outputs, and perhaps some nirvana looking outputs too..

Lots to be optimistic & excited about for January.

 

Am I mistaken or is this showing the possibility of two eamt events unfolding

[johnholmes]

 

 

500 mb anomaly update Wed 23 December

Ec-gfs=unable access by 1130?

Noaa and it shows marked meridional flow over most of the chart w-e so no change in the overall pattern at 500 mb seems likely as a ‘mean’ chart for 6-10 days from now. Over e n America the trough looks a shade sharper/deeper; the ridge ahead of it is more marked and the trough ahead of that looks a bit sharper  and in about the same place as shown 24 hours ago. The 8-14 shows no change either from 24 hours ago or from the 6-10 output.

This would all suggest that the main 500 mb flow for most of the time will be showing meridional and the ridge-trough pattern seems to be at about the same longitude as before. So to me any wobbles suggesting the current pattern will change on the synoptic models can be disregarded.

Again don’t compare each run with the previous beyond about 120h maybe 144 hours. Do this as the charts move down below T+120h. I keep suggesting this, why?, because it does give a more balanced and usually a more correct idea of what the weather subsequently does. Below T+120h one can also compare GFS with EC and Met. They will converge as the time counts down to what we actually get.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

[Howie]

1 minute ago, johnholmes said:

 

 

500 mb anomaly update Wed 23 December

Ec-gfs=unable access by 1130?

Noaa and it shows marked meridional flow over most of the chart w-e so no change in the overall pattern at 500 mb seems likely as a ‘mean’ chart for 6-10 days from now. Over e n America the trough looks a shade sharper/deeper; the ridge ahead of it is more marked and the trough ahead of that looks a bit sharper  and in about the same place as shown 24 hours ago. The 8-14 shows no change either from 24 hours ago or from the 6-10 output.

This would all suggest that the main 500 mb flow for most of the time will be showing meridional and the ridge-trough pattern seems to be at about the same longitude as before. So to me any wobbles suggesting the current pattern will change on the synoptic models can be disregarded.

Again don’t compare each run with the previous beyond about 120h maybe 144 hours. Do this as the charts move down below T+120h. I keep suggesting this, why?, because it does give a more balanced and usually a more correct idea of what the weather subsequently does. Below T+120h one can also compare GFS with EC and Met. They will converge as the time counts down to what we actually get.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

THANK YOU, some people need to read this lol

[topo]

Is it worrying that although Polar Vortex seems pressed, it seems that we do not get a split or a major warming according to the latest GFS run?

[Battleground Snow]

I don't know about other members, but I'd take a couple of snowy weeks in early January, rather than hope the potential SSW cards fall right for us later down the line.

Might be making this up but, I think I seen Simon lee say SSW events only give us a 66% chance of a colder outlook in the UK?.

-15 uppers are great, but does it really matter if we get decent snow events with the jet tracking south? Appreciate it probably depends on where you live in the UK

[Blessed Weather]

Lots of posts have been moved over to the Chat/Moans thread where they are more appropriate. And I'm afraid a couple have disappeared. If you are posting general chat and/or personal opinion with no model analysis to support what you are saying then it doesn't belong in here. Please use the other thread. Thank you.

 

[Chesil View]

Is it just me? or has anyone else noticed the similarities between  the gfs  at 240 plus for the last few days and the synoptic situation around xmas new year 1978/79 and we all know where that winter went.  Worth a check on the wetterzentrale noaa charts archive if your interested.

Edited December 23, 2020 by Broadmayne blizzard

[Steady Easterly]

The gfs 06z run reminds me of the classic synoptics of the seventies/early eighties winters, very plausible as well given the anomaly charts, i suspect some of the negativity of charts half a month away is the milder at times in the south parts, which was also often the case in those classic Winters with large snowfalls along the boundaries.

[northwestsnow]

26 minutes ago, Allseasons-si said:

There is always one...

anyway,the gefs mean out to day ten is still rock solid,infact,it's even better than the 00z

check this out...

 

Brilliant mean !!

I've noticed the dominant vortex segment has been established a long way from home in recent days...

Its all looking good!!

[LRD]

GFS spaghetti. Still looking pretty tasty from around the 28th

A couple of things I've noticed - the 'warm' bump over Boxing Day and the 27th has trended warmer the last couple of runs

The op was a warm outlier or near-outlier at a couple of stages

Xmas Eve and Xmas Day trended that little bit colder. Nothing spectacular but it has

And the flat line around the -5 mark is lovely to see - can we upgrade that mean to -7 or -8 nearer the time?

Edited December 23, 2020 by LRD

[Snowmadsam]

Even for western coasts is looking....wait for it the right side of marginal, 27th onwards may yield surprises.

Otherwise, model output wise expecting surprises and these may show in more hi-res output soon, but feature maybe small

But I can feel a snow shield going up on the m4 corridor...

oop there it is..

 

[TSNWK]

2 minutes ago, LRD said:

GFS spaghetti. Still looking pretty tasty from around the 28th

A couple of things I've noticed - the 'warm' bump over Boxing Day and the 27th has trended warmer the last couple of runs

The op was an outlier or near-outlier at a couple of stages

Xmas Eve and Xmas Day trended that little bit colder. Nothing spectacular but it has

And the flat line around the -5 mark is lovely to see - can we upgrade that mean to -7 or -8 nearer the time?

And look at the green line for the op go off on one around the time the west based NAO brought in those milder uppers for the south.  

Brilliant to see

[Mair Snaw]

Fantastic model viewing continues, great time to be in here reading the fantastic views of some and as always the negative comments will come with every run. And please lets not mention missing data due to xmas and less flights etc.. onwards and downwards with the 2m temperatures and as ever get the cold in and then worry about the snaw!!