Model Output Discussion - Staying cold into the new year

[nick sussex]

Good agreement developing regarding a shortwave dropping south from the north .

A northerly looks unlikely now but it could be replaced by a more ne e flow.

However the complication is how that shortwave phases with the low pressure over mainland Europe .

And how deep it is to begin with . Firstly we want a shallow feature dropping south se , as shallow as possible , this will be easier to be absorbed by the Euro low .

It’s a very complex set up , it does have a high reward though if it goes well!

 

Edited December 31, 2020 by nick sussex

[winterof79]

1 hour ago, Ali1977 said:

What on earth are you doing to us ECM, day 10 is an absolute beauty!!

If this happens I think we should be thinking about the word HISTORIC!! However it is day 10, so let’s keep that in mind.

 

Closer to the here and now , this could produce some snow off the North Sea - -6/-8 uppers , or are the other perimeters not conducive??

Dew point and DAM look ok.

 

That ECM day 10 chart is an early  Feb 63 redux. 

[BLAST FROM THE PAST]

The UKMO is really cold and getting colder.  Bitingly cold E/NE winds and snow supportive....and we don’t need to wait until t144 either

t96

 BFTP

Edited December 31, 2020 by BLAST FROM THE PAST

[Methuselah]

1 hour ago, CreweCold said:

Models seem to be converging around days 8/9 now. 

Trop looks like it's going into reversal mode.

Much better runs overnight... Should be a relief to your left testicle, Crewe?

[I remember Atlantic 252]

1 minute ago, BLAST FROM THE PAST said:

The UKMO is really cold and getting colder.  Bitingly cold E/NE winds and snow supportive....and we don’t need to wait until t144 either

 BFTP

Aye, certainly looks better than GFS for Wed, on GFS looks like a low with a mild sector?

[TSNWK]

17 minutes ago, bluearmy said:

Haha!  Still nowt but rain from the easterly and the system working in from the continent still has Dp’s just too high but closer than we were on yesterday’s run and the west side of the low could throw up some snowy surprises into the western Home Counties and central southern England.  Of course the op development post day 7 is perfect to change the west to white ....

the Ukmo remains progressive re lower uppers and if that’s more correct than ecm then things will change on the predicted situation ..... but the two models diverge by day 6 in any case 

Thanks BA.. my currentfocus has been on early next week  from the easterly, we have seen since yesterday a slight improvement on numbers.    just another smidge lower.

The further into next week we go then the greater room for further improvements. 

So I'm thinking at present we have run out of time to improve tangibly on uppers for Sunday and early Monday, however don't think unrealistic to seek tweaks from Monday evening onwards to put most of us right side of marginal. 

Edited December 31, 2020 by TSNWK

[Battleground Snow]

Couldn't see the ECM mean posted at 240, truly incredible.

Also once the hi Res models like arome and Harmonie get the easterly in range thats currently 72-144, I think it will show a lot of snowy streamers.

 

[Bradley in Kent]

Good morning all, 

Amazing looking charts even if most are yet to have snow, still waiting here in Kent but a real hard frost instead which I'll take for now!

Must say as others have already mentioned, the models really are showing that high risk high reward scenario. It'll be either one remembered for disappointment or one remembered for how good it was especially after the previous winter and 2020 which, let's face it, wasn't the best of years...

I'm sure the forum hosts will know but I wouldn't be surprised if there are more posts now compared to the whole of last winter!

I'm still very cautious not to get totally sucked in as things do often go wrong with cold spells, but this is so much better than 'oh, high pressure over the Med, long fetch SW, oh wait high pressure in the Atlan, oh no its toppling...'

[winterof79]

Here's the gfs // precip forecast. You can see the continental disturbance arrive shortly before our Polar disturbance brings in colder temps to the party. Dew points for ref. 

[TSNWK]

If there is perception from streamers this week can we expect an help with evaporation cooling?

[bluearmy]

1 minute ago, Battleground Snow said:

Couldn't see the ECM mean posted at 240, truly incredible.

Also once the hi Res models like arome and Harmonie get the easterly in range thats currently 72-144, I think it will show a lot of snowy streamers.

Well they can only show snowy streamers if the gfs, gem and ec models are currently wrong - which they could be .......but is that likely ??

[feb1991blizzard]

25 minutes ago, bluearmy said:

Haha!  Still nowt but rain from the easterly and the system working in from the continent still has Dp’s just too high but closer than we were on yesterday’s run and the west side of the low could throw up some snowy surprises into the western Home Counties and central southern England.  Of course the op development post day 7 is perfect to change the west to white ....

 

The slider could change anywhere to white but would have thought the setup after was perfect to change the South East to white!

[Battleground Snow]

5 minutes ago, bluearmy said:

Well they can only show snowy streamers if the gfs, gem and ec models are currently wrong - which they could be .......but is that likely ??

We will find out soon, obviously coastal areas will really struggle, and it will probably alternate between rain and snow at times, but inland has a very good chance I think

Edited December 31, 2020 by Battleground Snow

[bluearmy]

6 minutes ago, feb1991blizzard said:

The slider could change anywhere to white but would have thought the setup after was perfect to change the South East to white!

Was supposed to say ‘wet’!

edited now .....

Edited December 31, 2020 by bluearmy

[Chesil View]

5 minutes ago, bluearmy said:

Well they can only show snowy streamers if the gfs, gem and ec models are currently wrong - which they could be .......but is that likely ??

Well Blue there in lies an interesting question. Bearing in mind how they overplayed and mispositioned various snow risks this past week it could be equally likely that they might be underplaying them next week. Just a thought. Not picking an argument.

[Anthony Burden]

ECM taking SSW very positively at 240hrs very cold -10 hpa  and strong north easterly Russian 

flow.Superb chart has to be the best so far hope it remains down to zero hrs.

[bluearmy]

2 minutes ago, Broadmayne blizzard said:

Well Blue there in lies an interesting question. Bearing in mind how they overplayed and mispositioned various snow risks this past week it could be equally likely that they might be underplaying them next week. Just a thought. Not picking an argument.

I get that but I don’t think this week was that badly modelled re snowfall. the conditions aloft were marginally supportive and we know that disturbances under a trough are impossible to predict 

a convective easterly with some disturbances in the flow is quite different. The ingression of the euro trough could be a wild card though as that could involve air sourced from elsewhere 

[Paul_1978]

49 minutes ago, Blessed Weather said:

Here's the latest forecast charts from Berlin University for both temperatures and zonal winds 30th Dec. SSW's are declared according to what is happening with zonal winds at 10hPa 60N. You will see from the forecasts (black line) that temperature has already been rapidly climbing, causing the zonal winds to consequently plummet below zero into negative territory (which means winds switch from westerly to easterly) - that's the SSW taking place. Looking like a few days yet for winds to reverse:

Temps:  Winds:

Source: https://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

This is mind, I think we should start seeing this reflected in the normal model output from today. I am always skeptical that the model output doesn't show the effects of an SSW before it's happened. Should be an intriguing period of model watching coming up!

[KTtom]

10 minutes ago, bluearmy said:

Well they can only show snowy streamers if the gfs, gem and ec models are currently wrong - which they could be .......but is that likely ??

I've got say, thank god for Bluearmys regular input on this forum to install a sense of realism amongst the exaggerated and hope-casting posts about steamers etc which could lead to unrealistic expectations for those who depend on this forum for  guidance. Bluearmy is definitely the one to go to this year for a fair and accurate reflection of what is actually shown, as someone said on the previous page, its not happening until he says it is!

Apologies for anyone eating their breakfast 

 

[Polar Maritime]

Yes agree with above, Thanks for your valued input blue and that also goes with everyone else's contribution here in the MOD it's what makes this forum so interesting.

Happy New Year all!

[ancientsolar]

people say the models need to show uppers of -8 for us to get snow in (to lower level?) 
~ If there is already lying snow, how much does this affect the requirement of the uppers?

[bluearmy]

Ec raw data still showing the issue 

[bluearmy]

The eps clusters days 8/10 show a range of options on the dropping trough. The ec op cluster isn’t the most supported evolution - the 30% option more akin to yesterday’s op runs that drops the trough to the west and then pivots it. Hopefully the eps are a day behind the ops ! 

[Chesil View]

2 minutes ago, Polar Maritime said:

Yes agree with above, Thanks for your valued input blue and that also goes with everyone else's contribution here in the MOD it's what makes this forum so interesting.

Happy New Year all!

Here here. I find Blues realistic and down to earth analysis and input invaluable.  Reminiscent of the late great Philip Eden.

[Justin1705]

Right just going through the fax. And noticed an occluded front, and a trough following after it, overnight Friday and into Saturday. Could be a little feature bringing some wintry showers to the was and london and south east. As per Arome and arpege it has some agreement of showers, or weak bands of precip pushing from north sea and northern counties. Interesting to see how far south they will make it. Although any accumulation is out of the question some flakes may be possible. Whats everyones thoughts?

7025B6AD-0B64-441E-835F-8FDD003BE3F8.webp

Edited December 31, 2020 by Justin1705