Hunt For Cold: Model Discussion - Heading Into Christmas

[carinthian]

A dream day ski-ing on the Aineck Mountain. Last one for 6 weeks before embarking on my trip to Vancouver via Sussex for a few days over Christmas. Well what a messy outlook from most NWP models for Christmas. None really showing the same out puts at 168t. Anyway , this what our shows this morning ( very latest ) and yes a Easterly drift over Southern Britain on Christmas Day as the Atlantic trough pushes slowly and erractically NE from the Azores towards the Channel with possible shallow low circulation. Pressure rises to follow across the UK  generally in the period 168-240 . A lot of uncertainty in the medium longer term charts , so verification expected to be low. Interesting thoughts about ECM runs which seem to indicate much lower heights to the NE in the run up to New Year but as yet has little support from the main models but not to be discounted.  As I say all a bit messy but further developments could move at a pace just before Christmas , so one to watch.

C

[northwestsnow]

2 minutes ago, karyo said:

I'd say mainly the 6z. The previous run was not as favourable with a chunk of the vortex thrown over us at 30hpa.

I'd say the 00z para completely removed the PV from its home..

I'm even more of an amateur wrt the strat to be fair - guess its a displacement , but a good one!

[feb1991blizzard]

3 minutes ago, karyo said:

I'd say mainly the 6z. The previous run was not as favourable with a chunk of the vortex thrown over us at 30hpa.

This profile on the 6z has massive potential, it could end up a Northerly as just the starter for the main course but coldening the continent to a very significant extent waiting for the Easterly to advect the 87 rdux our way.

[karlos1983]

Cold ENS members grow 

Edited December 18, 2018 by karlos1983

[Glacier Point]

Decent signal for a strong mid latitude ridge signal across Christmas week in the EPS and GEFS for NW Europe. This looks plausible on tropical and extratropical signals right now.

Thereafter, EC locks in a -AO out until February and drives the NAO negative mid January onwards. I would be expect movement of mid latitude ridges north and north-westwards over time as the impacts of the stratospheric warming take effect.

[shaky]

51 minutes ago, northwestsnow said:

At least it should be seasonal

850s not important in late Dec under high pressure..

Yup and i say same could be sed bout january!!high over us clear skies we could be lookinng at sub zero  temps night and day!!february maybe not as extreme with the sun slightly higher especially mid feb onwards!!

[swfc]

2 minutes ago, karlos1983 said:

Cold ENS members grow 

Karlos when or if the change comes when would you hope to see the effects of wind reversal ete on the mo???

[northwestsnow]

6Z para going for it too by the looks of it..

[feb1991blizzard]

Welcome aboard GFS(p)

[Jonathan Rhodri Roberts]

I know the seas around us don't reach their coldest until end of Feb/ start of March but do these look a bit higher than normal for mid December, especially in the English Channel & Irish Sea? If so, would I be right thinking this would have a big knock on effect snow-wise particularly for coastal locations as we head into January? 

Edited December 18, 2018 by Jonathan Rhodri Roberts

[Leo97t]

Call me mad but I'm now thinking this January could be a sub 1c month, on the scale of something like jan 85, dec 81, Jan 87 or Jan 79. Think we'll see a truly deep period of cold from about the end of the first week. Almost all signals in our favour. And a huge uk high is normally how prolonged spells begin. Even if the ssw is a displacement, it looks like it will be in the best possible location for cold. All looking great atm! 

[Eskimo]

4 minutes ago, Jonathan Rhodri Roberts said:

I know the seas around us don't reach their coldest until end of Feb/ start of March but do these look a bit higher than normal for mid December, especially in the English Channel & Irish Sea? If so, would I be right thinking this would have a big knock on effect snow-wise particularly for coastal locations as we head into January? 

Yes would be detrimental to those along the immediate coast due to warmer on-shore breeze, but fantastic for those inland. Higher SST's will create more moisture = more potent showers. The greater the difference between the air temperature (colder the better) and SST (warmer the better), the more intense the precip will be. 

Edited December 18, 2018 by PerfectStorm

[feb1991blizzard]

1 minute ago, Jonathan Rhodri Roberts said:

I know the seas around us don't reach their coldest until end of Feb/ start of March but do these look a bit higher than normal for mid December, especially in the English Channel & Irish Sea? If so, would I be right thinking this would have a big knock on effect snow-wise particularly for coastal locations as we head into January? 

Yes, they're fantastic, much more margin for error in order to get frenzied lake effect, you would get  massive dumpings right inland with around -12c over those.

[feb1991blizzard]

1 minute ago, Leo97t said:

Call me mad but I'm now thinking this January could be a sub 1c month, on the scale of something like jan 85, dec 81, Jan 87 or Jan 79. Think we'll see a truly deep period of cold from about the end of the first week. Almost all signals in our favour. And a huge uk high is normally how prolonged spells begin. Even if the ssw is a displacement, it looks like it will be in the best possible location for cold. All looking great atm! 

Not out of the question at all, but you would need to start seeing some good charts coming out soon on the runs that go out to 16 days plus.

[Leo97t]

Just now, feb1991blizzard said:

Not out of the question at all, but you would need to start seeing some good charts coming out soon on the runs that go out to 16 days plus.

Yes true. A very mild start would rule out a sub 1c pretty much form the get go

[feb1991blizzard]

Just now, Leo97t said:

Yes true. A very mild start would rule out a sub 1c pretty much form the get go

although having said that 87 came in at 0.7 with a mild start and end, but that was extreme, if you only have a week or 2 of cold then you pretty much need it to tear up the record books in terms of intensity in order to get below 1c

[northwestsnow]

4 minutes ago, feb1991blizzard said:

Yes, they're fantastic, much more margin for error in order to get frenzied lake effect, you would get  massive dumpings right inland with around -12c over those.

Hmmmmm.. from a source from the east i would agree.. from the north west there would be huge modification.

[weirpig]

Much better runs on the 6z   A spilt on the Gfs  and what looks like close to a split of the Para     

 

 

[feb1991blizzard]

1 minute ago, northwestsnow said:

Hmmmmm.. from a source from the east i would agree.. from the north west there would be huge modification.

true.

[karlos1983]

15 minutes ago, swfc said:

Karlos when or if the change comes when would you hope to see the effects of wind reversal ete on the mo???

Hi swfc 

im not Going to pretend I know what’s going to happen when and where. All I’m trying to do is look for any trends, so following the EC ENS, looking at the ens Heights for Iceland etc, to attempt to build my own picture.

I don’t expect anything super cold this side of New year. But I think the eye candy charts will soon start pouring out.

sorry if I’ve not answered your question. I’m not one for really sticking my neck out as the weather makes fools of the best of forecasters, nevermind an amateur enthusiast like me. I’m optimistic though  

[Jonathan Rhodri Roberts]

7 minutes ago, PerfectStorm said:

Yes would be detrimental to those along the immediate coast due to warmer on-shore breeze, but fantastic for those inland. Higher SST's will create more moisture = more potent showers. The greater the difference between the air temperature (colder the better) and SST (warmer the better), the more intense the precip will be. 

That's what I was thinking, so it's fair to say here on the south coast of Wales there'll be nothing for us to get excited about for a good few weeks yet with any lows very likely to bring the plain old rain but further inland and particularly the valleys could do very well in January? 

[northwestsnow]

Exeter remain confident of an Easterly into the New year.

[weirpig]

3 minutes ago, northwestsnow said:

Exeter remain confident of an Easterly into the New year.

Dont know  i spotted a comma in the recent update  that was not  on the previous one.  Backtrack???.

[northwestsnow]

As Feb alluded too earlier..

I would hope expect to see some more appealing charts beginning to appear in the longer range very soon ..

[weirpig]

I could be wrong  but didnt the Ecm ensembles  show a split strat  from last night?.

Edited December 18, 2018 by weirpig