Model output discussion - winter proper underway

[Chesil View]

Just now, Frosty. said:

The thinking is, or certainly was that the northern arm of the jet will weaken considerably again as we go further into January following it's angry christmas / new year phase..?..really hope Jan / Feb deliver the kind of severe cold from the East we have been sadly lacking in the last few years..

yes Frosty I hope so too although the 15-30 day meto update is more indicative of a nose of sceuro high over the south with the jet riding over the top to the north. However if the jet does weaken in those circumstances it would allow the high to build north and west.  Easterly outbreaks are great for cold and snow in the east but not great else where they also tend to be apart from the legendary 47 and 63 relatively short lived. Better an icewegian ridge with lows attempting to move in to spread the snow around the uk a bit more

Edited December 20, 2017 by Broadmayne blizzard

[karyo]

18 minutes ago, northwestsnow said:

This is from the GFS model, and i have to confess, i'm not entirely sure what effect this will have down the line..

The vortex doesn't look that bothered though as this is not a major warming. If a SSW shows up there will be a lot of red on that map.

[bluearmy]

24 minutes ago, northwestsnow said:

This is from the GFS model, and i have to confess, i'm not entirely sure what effect this will have down the line..

Just surfing around the edges NWN. 

[Singularity]

Well, as far as I can determine, the global atmospheric angular momentum (GLAAM) budget is continuing to advance toward phase 4 of the GWO and subsequent return to positive AAM values, which flies in the face of the modelling by GEFS and perhaps even other models, which want to keep it away from that phase and even trend it a little more negative.

I can't divulge exactly what I think this will mean, but I will say that I'm not surprised the models are making such large adjustments from day to day, as the initial conditions for each run are repeatedly deviating significantly from the modelled versions.

[bluearmy]

NAVGEM ?  Really ??

the polar ridge from the neg EPO has been a given for over a week now, courtesy of x model ens guidance. Ecm op has been most gung ho getting this over the pole - I have a view that the ops could be better on resolving this feature than the ens which is counter intuitive at the range we are still looking at. 

I wouldn’t be making any assumptions on what happens after day 7 at the moment 

[Frosty.]

I really hope winter 2017/18 on a knife edge still holds true and that we won't have to endure the usual damp squib in Jan / feb...anyhoo..the models at least show plenty of action during the christmas  / new year period following this weeks benign mild bore fest damp squib! 

Edited December 20, 2017 by Frosty.

[frosty ground]

Looking at the 06z run changes around Greenland have allowed some wintry potential to again turn up on boxing Day

High ground up north setup but

Quickly followed by a soaking for the south!


and from this morning run, we are starting to se a firming up of a short lived cold outbreak around the 26/28th

Edited December 20, 2017 by frosty ground

[Paul_1978]

26 minutes ago, Broadmayne blizzard said:

yes Frosty I hope so too although the 15-30 day meto update is more indicative of a nose of sceuro high over the south with the jet riding over the top to the north. However if the jet does weaken in those circumstances it would allow the high to build north and west.  Easterly outbreaks are great for cold and snow in the east but not great else where they also tend to be apart from the legendary 47 and 63 relatively short lived. Better an icewegian ridge with lows attempting to move in to spread the snow around the uk a bit more

I've seen plenty of reference to "Sceuro" and "Scrussion" on here, but this is the first time I've seen an "Iceweigian" 

[Chesil View]

Just now, Paul_1978 said:

I've seen plenty of reference to "Sceuro" and "Scrussion" on here, but this is the first time I've seen an "Iceweigian" 

Not an original from me Paul. I think Feb 1991 blizzard used it the other day and I thought it summed up what we need to get the most snow to the most people perfectly. lol

[swilliam]

Could be slidergate 2 developing  - this has shown up for  a few runs now.

[frosty ground]

We get a slider of sorts on the GFS around the 192 time, which could giver wintry potential to the North and east of where it tracks.


Or what Swilliam said

Edited December 20, 2017 by frosty ground

[nick sussex]

Hardly inspires much confidence when the big 3 disagree at T144hrs.

Part of the problem is likely to be something NOAA alluded to in the past.  Apparently theres a lack of data coverage north of the Bering Sea which for the current set up could be an issue given the ridging from the Pacific side is the main point of contention today.

Reading the extended forecast discussion for Alaska they do mention poor continuity between runs, if you look at the differences they centre over the handling of low pressure. The ECM effectively forces a lobe of high pressure into Greenland because of its different view of that.

The high is boxed in and forced to go into Greenland, the GFS and UKMO allow the high to escape further west.

Edited December 20, 2017 by nick sussex

[feb1991blizzard]

8 minutes ago, swilliam said:

Could be slidergate 2 developing  - this has shown up for  a few runs now.

TBH I couldn't see that type of result occurring from that setup, plus theres really no room for manoeuvre there - if that high is even a tiny bit more NE then its not happening.

[frosty ground]

13 minutes ago, feb1991blizzard said:

TBH I couldn't see that type of result occurring from that setup, plus theres really no room for manoeuvre there - if that high is even a tiny bit more NE then its not happening.

Interestingly the GFS does see that type of result from that setup 

[feb1991blizzard]

8 minutes ago, frosty ground said:

Interestingly the GFS does see that type of result from that setup 

Your right it does see those resultant PPN type charts with the whole country covered in a blanket, interestingly though I don't, and I doubt most professional meteorologists would either.

[frosty ground]

2 minutes ago, feb1991blizzard said:

Your right it does see those resultant PPN type charts with the whole country covered in a blanket, interestingly though I don't, and I doubt most professional meteorologists would either.

I think those charts show the potential of Wintry PPN, they do not show a blanket of snow, Not sure why you would think they do. Also I am not sure why you are making a point just so you can dismiss it as no one else as stated there will be blanket of snow. What you replied to was a post highlighting the potential for a slider, you then dismissed it as a possibility. 

The synoptics clearly show potential for Wintry weather more so the North and east of the low, and is clearly possible.  

[Ali1977]

After a few days of boring GEFS FIs we now have some interesting looking ones cropping up, PV by no means raging and the Euro high under plenty of pressure. Turn of the year not looking too good, but cone the 2nd week of Jan it's looking promising - backed by the professionals.  I feel it's been ages since a full on cold Jan, fingers crossed. 

Edited December 20, 2017 by Ali1977

[northwestsnow]

I mentioned Europe the other day and the 00z GEFS for moscow are absolutely staggering!!

EXTREMELY mild air forecasted to hit as far east as moscow over christmas- basically pretty much all the cold is bottled up over canadian arctci!

Might actually be colder here than moscow 26th dec- 30th dec-

Edited December 20, 2017 by northwestsnow

[swilliam]

57 minutes ago, feb1991blizzard said:

TBH I couldn't see that type of result occurring from that setup, plus theres really no room for manoeuvre there - if that high is even a tiny bit more NE then its not happening.

Yes - but this is where we started with the previous one and then it kept adjusting S and ended up in the Midlands - this could do the same or not - we will see. It is something of interest at any rate.

[Ali1977]

2 minutes ago, northwestsnow said:

I mentioned Europe the other day and the 00z GEFS for moscow are absolutely staggering!!

EXTREMELY mild air forecasted to hit as far east as moscow over christmas- basically pretty much all the cold is bottled up over canadian arctci!

Might actually be colder here than moscow 26th dec- 30th dec-

P20 would certainly come as a shock then, bitter Siberian air through Moscow (-28) into Europe. Cherry picking but heh!! 

[Iceaxecrampon]

GFS 06z

Well a mobile pattern of weather post Christmas Day on offer - one to watch but blink and you'll miss it.

Copycat Slider Low similar to last weeks but not as intense?

Pick of the bunch.

 

Reverting to type like today's clag.

Edited December 20, 2017 by Iceaxecrampon

[Iceaxecrampon]

Cumbria Ensembles have scatter agreement of sorts and a ppn spike.

Something brewing and to look forward to?

[offerman]

The problem we seem to consistently have is this huge Azores High.

 

Some rightly said recently it used to be semi but now is a permanent feature in that location.

 

I have drawn where it needs to be for us to have some decent cold and snow.

In the 1980s i remember on a Michael Fish forecast extending all the way from Azores right up to Greenland.

 

It seems its never going to happen again. It needs to move away. westward or northward. That is where the problem is for cold lovers.

Of course as well i have not drawn on the Arctic high or Siberian High  as these also bring cold and equally as rare.

 

 

 

 

 

 

 

 

 

Edited December 20, 2017 by offerman

[mulzy]

1 minute ago, offerman said:

The problem we seem to consistently have is this huge Azores High.

 

Some rightly said recently it used to be semi but now is a permanent feature in that location.

 

I have drawn where it needs to be for us to have some decent cold and snow.

In the 1980s i remember on a Michael Fish forecast extending all the way from Azores right up to Greenland.

 

It seems its never going to happen again. It needs to move away. westward or northward. That is where the problem is for cold lovers.

Of course as well i have not drawn on the Arctic high or Siberian High  as these also bring cold and equally as rare.

 

 

 

 

 

 

 

 

 

The Azores High is the winter killer - always has been, always will be.  

[swfc]

6 minutes ago, mulzy said:

The Azores High is the winter killer - always has been, always will be.  

Thats not actually true tbh.many a classic winter came about with the AH pushing way north and north east.that said I'm getting on and possibly thinking way back