Model output discussion 24/01/21

[chris55]

Saturdays low moving in does need watching.

Lots of mild air tied up in it and ahead of it, it all depends how it interacts with the colder air to the north of it, and what track it takes. At face value  it all looks a bit to warm for any snowfall and it pulls away south before the cold get in, but if it were to develop into the channel there is a chance of the colder air wrapping around with rain turning to snow.

UKMO taking it south, probably the most likely scenario.

Edited January 26, 2021 by chris55

[MJB]

 

Snow across England and Wales on Sunday for a time 

Heads North before turning to sleet then rain in the South 

 

 

 

[nick sussex]

Typical just as the GFS improves in the earlier timeframe the UKMO now goes the other way !

Again we’re back to discussing that shortwave to the ne !

[chris55]

ICON with a slider of sorts on Sunday into Monday. 

 

Edited January 26, 2021 by chris55

[Chesil View]

Tamara's post are always very interesting if somewhat complex for the average (and I count myself as very average) southern snow chaser like myself. She gives her honest opinion on what's she sees given her undoubted high level knowledge of atmospheric dynamics and forcings etc.

Her knowledge based on the current dynamics suggests to her that a prolonged freezing spell is not especially likely. Not utterly impossible but not likely.

However as this winter has already taught many parts of the UK already  You don't need a prolonged freezing spell to get multiple significant snowfalls  which as Tamara rightly points out is the bias of many of us (including myself) on this forum.

One final point Tamara saying something is unlikely does not make that something impossible.

 

[Battleground Snow]

GFS OP may go on to get interesting here if that Iceland circular wedge can develop further and send the lows further south.

 

 

[nick sussex]

The GFS now attempting a second go at disrupting energy further south with another wedge of heights to the ne helping .

Looking at the upstream pattern if that troughing over the UK could clear se an east ne flow wouldn’t be a leap of faith .

[Day 10]

I've moved on from Thurs not gonna happen.

Sunday's ICON.

Meant for the regional but may as well leave it here as it covers the UK.

Edited January 26, 2021 by Day 10

[Griff]

Parallel determined to slow the progress a bit more, the theme of late

[Griff]

And op.... Might it  

Edited January 26, 2021 by Griff

[offerman]

27 minutes ago, MJB said:

Apart from this 

Snow crossing the UK

Hi MJB

 

but how can it snow when there will be no cold in place , no -5cs 850  only 0-850 down here ??

recently down here there was a temperature of -2 with DP of -1 and it rained .

so how come with far warmer temperatures showing on Saturday and Sunday can there possibly be snow? There will have been no cold air coming in to make it a transient affair that I can see .

Thanks 

 

 

[nick sussex]

The displaced Azores high can actually help . If it ridges nw enough to slow any low pressure out of the USA.

That can then work in conjunction with the wedge to the ne.

Its a bit of a race you need shortwave energy south of Greenland to have cleared away before the Atlantic low can phase with that .

Edited January 26, 2021 by nick sussex

[mountain shadow]

3 minutes ago, Griff said:

Parallel determined to slow the progress a bit more, the theme of late

Regrettably the UKMO (better performer) is dire and very very wet.

[Griff]

Looks a bit like recent gem runs

[ICE COLD]

GFS going with the meto update ??? 

[chris55]

3 minutes ago, Day 10 said:

I've moved on from Thurs not gonna happen.

Sunday's ICON.

Meant for the regional but may as well leave it here as it covers the UK.

UKMO also interesting for Sunday, depending on where the front is sitting relative to the boundary cold/mild (which we can't see on the 500s/850s ) but Sunday is looking good for at least a period of heavy snow for many, looks like turning back to rain as of todays runs but will be nice to see nonetheless.

UKMO 120

[Battleground Snow]

1 minute ago, Griff said:

Looks a bit like recent gem runs

The mean was showing this pattern earlier, but just a little later on.

Edited January 26, 2021 by Battleground Snow

[Griff]

Just now, Battleground Snow said:

The mean was showing this pattern earlier, but just a little later on.

I'd settle for this! 

[ICE COLD]

There’s your north easterly @nick sussex

[nick sussex]

Yes ! The wedge will get cut off and start to develop . Pressure should start to build to the north now.

We need that to strengthen to help advect  the cold air sw. In a sense to help the cleaner flow from the east ne .

Edited January 26, 2021 by nick sussex

[Day 10]

Just now, ICE COLD said:

There’s your north easterly @nick sussex

Let the big freeze finally begin!

[ICE COLD]

1 minute ago, nick sussex said:

Yes ! The wedge will get cut off and start to develop . Pressure should start to build to the north now.

Think this is gonna go to boom town Nick

[Severe Siberian icy blast]

4 minutes ago, chris55 said:

UKMO also interesting for Sunday, depending on where the front is sitting relative to the boundary cold/mild (which we can't see on the 500s/850s ) but Sunday is looking good for at least a period of heavy snow for many, looks like turning back to rain as of todays runs but will be nice to see nonetheless.

UKMO 120

Fairly close to an undercut there it wants to go under 

[chris55]

Days 8-9 on GFS.......cold air digging in....

[SLEETY]

This is excellent run,hopefully its not just a one off like yesterdays mega cold Easterly which was gine 6 hours later