Model discussion - hunt for cold - Christmas countdown

[TSNWK]

2 minutes ago, snowking said:

Just to throw some more chaos in…

 

MOGREPS sticking with the milder bump during Xmas eve/day, but fairly firmly behind a colder picture thereafter, even in the south in the majority of cases

There’s some way to go on this yet 

Whats the darker blue line please? Op? If so thats an ice day in London on 27th.. against ECM... Anyone seen ukm168 I can't find it

[BLAST FROM THE PAST]

This is why wait until Wednesday.  Had a quick look, Ukmo is superb.

Have a look at the 850s, a steady and solid southward movement of cold air.  The big day to would be very cold 

BFTP

Edited December 19, 2021 by BLAST FROM THE PAST

[Malarky]

For anyone just joining us this morning… we’ve had a cracking GEM, a decent UKMO, middling ECM, and a GFS that looks to have found a new version of physics.

After a few runs yesterday where the block seemed to be strengthening in all the right places, that signal appears to have waned somewhat.

Nothing disastrous is showing on any model in the reliable timeframe.

Game on. Knife-edge. This is why we love this.

[MattStoke]

1 hour ago, Jason Edwards said:

Writings been on the wall for a few days on this, ECM puts that writing in paint.

Low Pressure will simply pass over the UK as it always does in these situations, it will only be cold enough to snow in a line from Cumbria northwards in my opinion.

Every year this happens, as soon as you see cold modelling being pushed back on the charts its obvious which way it will go.

One only needs to see the Ensembles anywhere south of the Midlands to see this cold snap around 27-29 will be confined to Midlands North and a quick (but temporary) return to Westerlies follows.

Im not holding much hope for seeing a cold and snowy winter in the UK at all this Winter, those times have gone just isnt going to happen...ever.

Posts like this are misleading. Calling something as if it’s a done deal. Nonsense.

Edited December 19, 2021 by Blessed Weather
Toned down.

[Ali1977]

Mogreps look like they are better to me, the slider is further south on most - only 3 look Midlands North 

Edited December 19, 2021 by Ali1977

[Evie Aviation]

54 minutes ago, Jason Edwards said:

Writings been on the wall for a few days on this, ECM puts that writing in paint.

Low Pressure will simply pass over the UK as it always does in these situations, it will only be cold enough to snow in a line from Cumbria northwards in my opinion.

Every year this happens, as soon as you see cold modelling being pushed back on the charts its obvious which way it will go.

One only needs to see the Ensembles anywhere south of the Midlands to see this cold snap around 27-29 will be confined to Midlands North and a quick (but temporary) return to Westerlies follows.

Im not holding much hope for seeing a cold and snowy winter in the UK at all this Winter, those times have gone just isnt going to happen...ever.

I’m new, but even I know that this is based on your personal  thoughts and not on any fact.. which is what I assume a model thread is for?

[Rayth]

The absolute brakes have been put on the zonal winds 

 

 

[Frosty.]

Fantastic output this morning if you’re a coldie!..The GEFS / ECMWF mean continues to trend colder in the mid range which is perfect timing for Christmas!…the operational runs show potentially very cold and for some, snowy conditions at Christmas…the Gem gets a special mention..it’s enough to make a coldies heart sing with joy….honestly, it could be amazing! ️ …might wax the sledge!    

Edited December 19, 2021 by jon snow

[Evie Aviation]

7 minutes ago, Malarky said:

For anyone just joining us this morning… we’ve had a cracking GEM, a decent UKMO, middling ECM, and a GFS that looks to have found a new version of physics.

After a few runs yesterday where the block seemed to be strengthening in all the right places, that signal appears to have waned somewhat.

Nothing disastrous is showing on any model in the reliable timeframe.

Game on. Knife-edge. This is why we love this.

Thank you for this info

[snowking]

3 minutes ago, TSNWK said:

Whats the darker blue line please? Op? If so thats an ice day in London on 27th.. against ECM... Anyone seen ukm168 I can't find it

The thicker blue line is the control run - I don’t think there is an operational run for the MOGREPS suite as it’s designed entirely to be an ensemble suite

In this instance that means the Control run is the only run for which the “starting conditions” are not changed in any way - I’ve no idea whether it’s any higher resolution than the other peturbations but I would guess not

 

[clark3r]

The models are not handling this well at the moment, twists and turns to come. GEM has to be my fav at the moment. Upgrades tonight would be great

[Malarky]

1 minute ago, Rayth said:

The absolute brakes have been put on the zonal winds 

 

 

Woah. Expect the models to struggle with this in the short term. 

[IDO]

Nothing has really changed, the models are struggling and high degree of uncertainty, the London 2m ens:

The difference this morning was that the control and op were in the milder options, yesterday the colder group. My problem is that since the GFS op upgrade it does have a nasty trait of over-selling heights in FI which constantly means we are disappointed as we count down to T0. 

As has been the way for a few days, Christmas snow remains finely balanced and post-26th, split scenarios, and we await for x-model and inter-model agreement. This morning was the GFS skipping to another solution, with the split in the westerly flow further west over the US:

D8> 

That forces the trough to its east  towards the Atlantic and kills any chance of the wedge working for cold to the UK. Have I said I hate wedges as they are too fragile! The ECM moved towards that as well, where as yesterday both had that break further east favouring the UK. Let us see if this is a consistent new signal?

 

 

Edited December 19, 2021 by IDO

[Ali1977]

[The Northern Ramper]

1 hour ago, Ali1977 said:

Snowy ru up to day 9, minuscule change ms around day 2/3 could change the snow area by 400 miles and produce a sustained freeze - let’s hope it trends colder again by tonight and the Greeny high sticks around- there are plenty of drivers supporting longevity of cold so that could we happen 

Beautiful

[Chertseystreamer79]

20 minutes ago, Malarky said:

For anyone just joining us this morning… we’ve had a cracking GEM, a decent UKMO, middling ECM, and a GFS that looks to have found a new version of physics.

After a few runs yesterday where the block seemed to be strengthening in all the right places, that signal appears to have waned somewhat.

Nothing disastrous is showing on any model in the reliable timeframe.

Game on. Knife-edge. This is why we love this.

Nice...saved me a lot of scrolling! 

[LetItSnow!]

The handelling of this low pressure is such on a knife edge and borderline unforecastable that I would stick to Christmas Day MAX in terms of the charts. What happens after that is unknown. If the models don't have a handle on this, they can't make accurate assesments after that period. I reckon there's still about 3-4 more agonising model watching days ahead. Feels like we've been staring this down forever, doesn't it!?  Until then, cold and mild rampers can only dream and make educated guesses (if they're capable!) 

[iowpompeylee]

This is a very difficult situation to read, forecasters are scratching their heads even for a Christmas forecast. This is a rollercoaster! I’d much rather be on this than mild zonal. Signs are v good! Get the cold in first and the rest will follow! 

[blizzard81]

The ecm op has snow for me as early as Thursday now. An upgrade in the short term for northern areas with everything being brought forward a couple of days. 

[Grimplet]

Just now, iowpompeylee said:

This is a very difficult situation to read, forecasters are scratching their heads even for a Christmas forecast. This is a rollercoaster! I’d much rather be on this than mild zonal. Signs are v good! Get the cold in first and the rest will follow! 

Amen brother!

 

[That ECM]

9 minutes ago, LetItSnow! said:

The handelling of this low pressure is such on a knife edge and borderline unforecastable that I would stick to Christmas Day MAX in terms of the charts. What happens after that is unknown. If the models don't have a handle on this, they can't make accurate assesments after that period. I reckon there's still about 3-4 more agonising model watching days ahead. Feels like we've been staring this down forever, doesn't it!?  Until then, cold and mild rampers can only dream and make educated guesses (if they're capable!) 

I think Christmas Day is 48 hours to far to look. Cold in Shetland tho.

Edited December 19, 2021 by That ECM

[carinthian]

Morning all. Just have latest thoughts from the team . Oh, just a matter of interest for next weekends weather, I would suggest. Are we any wiser how things will pan out ? Currently, basically no. Models continue crucially to differ in positioning of the low in the SW reaches of the British Isles. However, the opinions of the expert do indicate quite a strong divide of the boundary between cold/milder air mass development across the British Isles during the period Christmas Eve into Christmas Day. The snow computer latest run flags up that boundary line , Galway Bay to Thames estuary . So based on that outer perimeter result , may give a clue as to how far south the divide is. Still far way out to produce snow values but the potential indications are shown in that zone. The feeling is UKMO run maybe be the nearest in its output with even some suggestion that the fronts maybe not even register.

Hope it helps but the feeling is nothing nailed on the latest runs.

C

[Dancerwithwings]

Currently...Foggy

Temp 2.6c...DP 2.4c....humidity 99%

edit....sorry guys wrong thread

 

 

Edited December 19, 2021 by Dancerwithwings

[Man With Beard]

7 minutes ago, iowpompeylee said:

This is a very difficult situation to read, forecasters are scratching their heads even for a Christmas forecast. This is a rollercoaster! I’d much rather be on this than mild zonal. Signs are v good! Get the cold in first and the rest will follow! 

Agree with this, my head says there will be a slight shift NW of everything because models often correct in the direction of the flow of the high, but you can't rule out snow on Xmas day anywhere considering the ECM ensemble has a mean channel low at D7!

[bluearmy]

34 minutes ago, Rayth said:

The absolute brakes have been put on the zonal winds 

 

 

Not sure I get this forecast looking at the recent gfs runs 

It’s on her site as current but it’s simply incorrect ……

Edited December 19, 2021 by bluearmy