Model discussion: Hunt for cold - into mid-January

[damianslaw]

ECM and GFS keep the theme of yesterday evening trend.. becoming more unsettled later in the coming week as the current high shifts SW. A broad westerly flow then ensues alternating to a NW flow at times.. as we move into February the NW flow gaining the upper hand as we wee more unstable air penetrate further south- deeper digging of the trough is what enables this probably aided by the depth of cold coming out of the Pole.

A slow transition then to more unsettled as we end the month, turning colder at times in the north with a possible more concerted push of cold into February. As Nick says secondary lows could well be a feature as there is a suggestion the polar front will stretch somewhat with long sea fetch of polar air wrapped around it which is a classic enabler for secondary lows to develop at the low base point... always chance of snow on northern flanks in such scenario.

[Staffmoorlands]

Some milder weather to end the month on the UKMO. 
 

[tight isobar]

6 minutes ago, Staffmoorlands said:

Some milder weather to end the month on the UKMO. 
 

With+144 being  about the marker point right now for pattern change!. Not long after this pm incursion looks the form- so any notable milder Tm Air  shortlived. And we await the deciphering for how cold- and indeed prolonged any cold shots live out. Anyway finally the shift is on .

Edited January 22, 2022 by tight isobar

[BLAST FROM THE PAST]

 

perturbation 12 sums up my thoughts were (and are) of end of Jan into early Feb very well.  NW’ly, N’ly gale to severe gales.  Look at the depth of cold achieved!!

 

BFTP

Edited January 22, 2022 by BLAST FROM THE PAST

[johnholmes]

This output from ECMWF may give coldies some hope?

http://www2.wetter3.de/Fax/00_ECMWF_ENS_p0_500hPa+144_240.gif

It is not yet backed up by the 500 mb anomaly charts but there is a glimmer of a change, perhaps?

 

[BLAST FROM THE PAST]

11 hours ago, damianslaw said:

I'll stick my neck out and shoot me down if wrong but I expect models to now trend towards an ever more unsettled pattern before month is out and into Feb with plenty of polar air in the mix rather than high pressure holding on. 

Agreed, and the turn around seems to be accelerating.  
 

BFTP 

[Tim Bland]

ECM has a brief period of interest next weekend.. 

[Midlands Ice Age]

11 hours ago, damianslaw said:

Sense only a matter of time before we see a more concerted push of cold air out of the polar regions.. it's been bottled up out of our reach at least for weeks and just needs a nudge..others have had some.. our turn next.. I know the weather doesn't work like that but we've had a number of fleeting teases..

I've been watching closely the Arctic patterns in the last 48 hours, as a part of my postings in the N H snow and ice blog.

For the first time this season, I can see a strong drive towards a major cyclonic spell in the Western Arctic.

As you suggest the very much colder air has been 'bottled up', mainly by high pressure,  and this has enabled a much colder Arctic air mass.

It now looks as if this may be about to change.

Currently a low is moving NE along the Greenland coastline.

In 3 days time it is expected to deepen further and be around the Svalbard regions. It is taking some 'milder' air with it,though anything coming off Greenland will not be warm at this stage.

GFS charts from C.R. to show the general flow of the Arctic...

I believe it is this pattern change which will lead to the forecast patterns we are about to see.

Today's charts -

               

 

 

and 3 Days time -

                       

 

Going ahead to 5 days and 10 days time sees the next North American low driving  towards Greenland and then swinging more south eastwards towards the UK, around the major Arctic storm system..

 

MIA   

 

 

Edited January 22, 2022 by Midlands Ice Age

[E17boy]

Morning peeps,

At long last I am seeing some posts now mentioning a change coming. I have always stuck to my thoughts that having some kind of Atlantic come back will be far better for us rather than sitting under the high which has up to now nearly taken 2 weeks away from us.
Lets hope now that we can get some gaps for colder incursions. Some light May at last be showing at the end of the tunnel. The waiting goes on 

[frosty ground]

1 hour ago, Staffmoorlands said:

Some milder weather to end the month on the UKMO. 
 

Some impressive mild uppers on that chart shame it will be low cloud drizzle fest 

[Battleground Snow]

Not too much change from yesterday,

Apart from the fleeting PM shots, the more interesting charts are after day 10,

With ECM not really buying a negative AO atm, we need to be cautious of these blocked GFS charts, it may be picking up the signal a few days too early.

[Nick F]

06z GFS struggling to get any of the Pm cold incursions (sub -5C T850) further south than northern England. Keeps wanting to build in high pressure across the south. So promise for northern areas for some brief windows for snow in the Pm incursions, particularly hills, cold rain for the south. Remains to be seen though how far south the cold air can get as we finish the month on a more mobile and unsettled theme in westerly or northwesterly flow. May have to wait until early Feb in the south for cold enough air to dig south for wintriness from the NW or N, but out of range of the reliable for now.

[Ruzzi]

1 hour ago, Staffmoorlands said:

Some milder weather to end the month on the UKMO. 
 

You must have the worst bartender in the country, no matter how hard he tries, your glass never gets above half empty  

Maybe skip the pub run from now on, the man is ripping you off

[Ali1977]

If only the Atlantic heights could link with those over the high Arctic, it’s a better looking day 11 chart though. We need these in the reliable!! 

[Battleground Snow]

Just now, Ali1977 said:

If only the Atlantic heights could link with those over the high Arctic, it’s a better looking day 11 chart though. We need these in the reliable!! 

Yep this run is what we want, vortex under massive stress here.

Need to see if the ECM picks this up over the next few days at day 10, and watch the EPS

[Nick F]

One day, one of these GFS FI screaming northerlies may come off ... but maybe not this winter of misfortune! 

.

[IDO]

The GFS has for a while indicated that in FI the higher lat blocks (wedges) will be on the other side of the NH meaning that the tPV will be based on our side. It is now trying to resolve how that tPv will act within the flow which is somewhat dependent on the modelling of the blocks over the Pacific/Asia>Siberia regions. So the 0z and 06z showing the variability of the modelling:

0z>  06z> 

Subtle variations on that theme. 

Assuming this is the direction of travel, we should def get a change from UK high, but too much uncertainty at the moment and GFS just giving us a preview of options run to run, some, like the 06z a bit more interesting. Again those wedges over the other quadrants are likely to dissipate so any changes are seemingly relatively transient.

HP remains the call for the rest of Jan.

Edited January 22, 2022 by IDO

[mushymanrob]

27 minutes ago, Tim Bland said:

ECM has a brief period of interest next weekend.. 

Now im a little confused here .... Im assuming that feature is so small it doesnt figure much on this chart which doesnt suggest the 528 dam, the 500hpa or 850 hpa values are low enough for snow.

 

[Nick F]

7 minutes ago, mushymanrob said:

Now im a little confused here .... Im assuming that feature is so small it doesnt figure much on this chart which doesnt suggest the 528 dam, the 500hpa or 850 hpa values are low enough for snow.

 

The low deepens rapidly on its track between your chart at Sun 30 Jan 00z to the one you quote at Sun 30 Jan 18z. T850s just about cold enough on northern flank at Sun 30 18z.

Still, the likelihood of that low coming off like that at that range pretty low I'd imagine.

Edited January 22, 2022 by Nick F

[Ali1977]

By day 8 the mean is close to showing a PM flow now with heights building in the Western Atlantic  , with some colder looking ENS either in place, or heading in!!

. It’s getting closer, but will it materialise I’ll be interested to see if the METO update changes to more of a PM type scenario 

Edited January 22, 2022 by Ali1977

[Ali1977]

And at day 9 the -6c mean 850s are into Scotland and heading south 

 

Edited January 22, 2022 by Ali1977

[JBMWeatherForever]

Yesterdays trend looks like it is for real and the pace of change should start to gather speed now.  From the pattern indicated, it seems the precursor to a significant northerly outbreak.  The progressive GFS should start to show this very soon, for the months end.  HOPEFULLY !

[minus10]

43 minutes ago, Nick F said:

06z GFS struggling to get any of the Pm cold incursions (sub -5C T850) further south than northern England. Keeps wanting to build in high pressure across the south. So promise for northern areas for some brief windows for snow in the Pm incursions, particularly hills, cold rain for the south. Remains to be seen though how far south the cold air can get as we finish the month on a more mobile and unsettled theme in westerly or northwesterly flow. May have to wait until early Feb in the south for cold enough air to dig south for wintriness from the NW or N, but out of range of the reliable for now.

Yes Nick. Seems a constant patten with the gfs to show a pm shot then downgrade it.

It seems that pm shots are never (or hardly ever ) upgraded. I suppose what with all the drivers at play and the seemingly endless supply of high pressure linked with the patten of the jetstream, the model keeps initially over estimating the occurence of a pm shot. Extremely frustrating for coldies...lets hope the early signs of changes for beginning of Feb can help with perhaps upgrading pm shots.....now there's a thought.

[Ali1977]

By day 11/12 much of the U.K. under -4c uppers on the mean and the Euro HP getting washed out - finally. I’ll be happy with PM shots and the chance of some transient snow at least !! If we are to have a spell of PM air then late Jan and early Feb is probably the best time for it!! 

[Jeremy Shockey]

GFS 06 z ensembles

Certainly some interest as we head into Feb with a good looking mean and lots of cold options.