Model output discussion - deep cold inbound?

[Malarky]

I am getting extremely excited by everything being posted. I need a wet flannel and a lie down.

Edited February 5, 2021 by Malarky

[Battleground Snow]

18 minutes ago, phil nw. said:

I think there is some, room for a switch in the gefs in particular.

We know in the situation where the Atlantic comes into blocking this model often throws too much energy ne. 

With signs of another block forming ahead we may well see the Atlantic stall before making any appreciable inroads. 

The operational runs will likely move around on this until maybe t72. 

We could well retain much of the surface cold under any ridging, although the sw quarter does seem the most at risk for some sort of warm up if only temporary. 

It does like fine margins which way the evolution goes after mid week. 

Wow, as late as 72, I was ready to conceed if the Ukmo and ECM at 144 hinted of the breakdown, the met office 15 day forecast may gives clues when it updates later, as I'm led to believe mogreps are later with the breakdown than even the ECM is showing. It's fascinating to watch this scenario play out either way 

MJO is still is still supportive of blocking in our locale (ECM more so).

Maybe we just got unlucky with the depth of cold that's in north America right now spawning a couple of big lows in the Atlantic.

This GIF is for 2M temps, not 850mb temps, phenomenal depth of cold, I can't imagine what it would be like to live under those conditions.

Edited February 5, 2021 by Battleground Snow

[Scott Ingham]

6 hours ago, MattStoke said:

UKV has 500mm (50+cm) of snow for some spots in East Anglia and the South East. May be overdone (Although I find this model is one of few that normally under does accumulation). Quite feasible though that some spots could see a foot or more, but more widely probably 15-20cm across some eastern areas. Certainly, I would expect a good few cm for more eastern and central areas (and a few spots in the west) than this model shows.

That 30-40cms in the south east int looking so outlandish on this chart!!

[Cavehill Snow]

13 minutes ago, Battleground Snow said:

Wow, as late as 72, I was ready to conceed if the Ukmo and ECM at 144 hinted of the breakdown, the met office 15 day forecast may gives clues when it updates later, as I'm led to believe mogreps are later with the breakdown than even the ECM is showing. It's fascinating to watch this scenario play out either way 

MJO is still is still supportive of blocking in our locale (ECM more so).

Maybe we just got unlucky with the depth of cold that's in north America right now spawning a couple of big lows in the Atlantic.

This GIF is for 2M temps, not 850mb temps, phenomenal depth of cold, I can't imagine what it would be like to live under those conditions.

As impressive as it is, the extreme cold has probably powered up the jet at just the wrong time for us. I know that some have said that in February it is possible for NE US/ Canada & ourselves to be cold simultaneously, however it is the depth of cold temperatures as the PV hits the Atlantic that has proven just too strong for heights to hold over here.

[Notty]

1 minute ago, Cavehill Snow said:

As impressive as it is, the extreme cold has probably powered up the jet at just the wrong time for us. I know that some have said that in February it is possible for NE US/ Canada & ourselves to be cold simultaneously, however it is the depth of cold temperatures as the PV hits the Atlantic that has proven just too strong for heights to hold over here.

... not yet though - just in model-land

[Howie]

9 minutes ago, Cavehill Snow said:

As impressive as it is, the extreme cold has probably powered up the jet at just the wrong time for us. I know that some have said that in February it is possible for NE US/ Canada & ourselves to be cold simultaneously, however it is the depth of cold temperatures as the PV hits the Atlantic that has proven just too strong for heights to hold over here.

So annoying

[Scott Ingham]

3 hours ago, Purga said:

Interesting (like Steve Davis ) GFS 06z brings back blocking and an easterly after D10.

Another twist to the drama?

 

Theres no doubts there are increasing signs in both suites of the +AAM effects from the 13th peak kicking in. 

The big question is will it be enough to extend the cold or will it be too late and mean a 3 or 4 warm up before back in the freezer?

Im 50/50 on both options this morning with the gefs and 500mb charts in particular keen for a breakdown by the weekend

[beefy201]

6 hours ago, bluearmy said:

The last three ops have been v unconvincing regarding pushing the Atlantic though - funnily enough, this run is the most enthusiastic by day 10 

It is

Somewhere may well be but the ‘whole se’ ???

who said somewhere?

[ITSY]

Anyone have a screenshot or link to the private ECM 06z precip/snowfall chart for the wider country on Sunday/Monday? Keen to see if it's moved or stayed with its 00z, esp given short-term Met alignment with Euro4...yesterday's was pretty sensational 

Edited February 5, 2021 by ITSY

[sheikhy]

2 minutes ago, ITSY said:

Anyone have a screenshot or link to the private ECM 06z precip/snowfall chart for the wider country? Keen to see if it's moved or stayed with its 00z, esp given short-term Met alignment with Euro4...yesterday's was pretty sensational 

Ive been waiting for the same thing!!!yesterdays did look pretty good!!probably gone little further south and east now like gfs!!

[Frosty.]

Just looking through the GEFS 6z perturbations, there are still some very cold ones next Friday, and some others reluctant to change too.... so although the operational is still progressive, there’s no guarantee the deep cold will be swept away this time next week, we’ve already seen the ECM delaying any potential change...anyway...enjoy the Freeze and the disruptive snaw!...it’s almost here..well, across parts of Scotland..it’s already arrived!!   

[KTtom]

44 minutes ago, Battleground Snow said:

Wow, as late as 72, I was ready to conceed if the Ukmo and ECM at 144 hinted of the breakdown, the met office 15 day forecast may gives clues when it updates later, as I'm led to believe mogreps are later with the breakdown than even the ECM is showing. It's fascinating to watch this scenario play out either way 

MJO is still is still supportive of blocking in our locale (ECM more so).

Maybe we just got unlucky with the depth of cold that's in north America right now spawning a couple of big lows in the Atlantic.

This GIF is for 2M temps, not 850mb temps, phenomenal depth of cold, I can't imagine what it would be like to live under those conditions.

It has just updated, seems to be backing the trend with wintry hazards restricred to high ground by the weekend. Strangely enough nothing on the following week but the cold soon to return after a mild spell. 

[bluearmy]

11 minutes ago, ITSY said:

Anyone have a link to the ECM 06z precip/snowfall chart for the wider country? Keen to see if it's moved or stayed with its 00z, esp given short-term Met alignment with Euro4...

its gone a bit east and lost some intensity 

however, the 06z and 18z runs have been doing this last day or so

[Battleground Snow]

4 minutes ago, KTtom said:

It has just updated, seems to be backing the trend with wintry hazards restricred to high ground by the weekend. Strangely enough nothing on the following week but the cold soon to return after a mild spell. 

Yeh it seems mogreps is backing the breakdown around day 10,  they are unsure of how far north the milder conditions will extend, may be that the far north escapes the blip entirely

[Tim Bland]

Looks like the Met have finally given into the fact that there will be a milder and wetter interlude from next weekend. The word ‘interlude’ is key though

[TSNWK]

3 minutes ago, KTtom said:

It has just updated, seems to be backing the trend with wintry hazards restricred to high ground by the weekend. Strangely enough nothing on the following week but the cold soon to return after a mild spell. 

That's fair enough sometimes it helps to have some uncertainty removed and that update suggests an enhanced signal to the pros if milder getting towards end of next working week. 

5 days of sub zero I hope for vast majority and it's live.......  From t60 hours

[sheikhy]

6 minutes ago, Tim Bland said:

Looks like the Met have finally given into the fact that there will be a milder and wetter interlude from next weekend. The word ‘interlude’ is key though

That than then gfs is right and ecm is wrong in keeping the cold in place!!!!where ecm might be correct  is the cold fighting back after!!!expect a more mild push at 144 hours on 12zs!!hope not though!!

Edited February 5, 2021 by sheikhy

[Premiere Neige]

48 minutes ago, Cavehill Snow said:

As impressive as it is, the extreme cold has probably powered up the jet at just the wrong time for us. I know that some have said that in February it is possible for NE US/ Canada & ourselves to be cold simultaneously, however it is the depth of cold temperatures as the PV hits the Atlantic that has proven just too strong for heights to hold over here.

Proven? The cold spell hasn't even started for most of us yet. I think we're getting a bit ahead of ourselves to say anything has been proven regarding a potential breakdown...

[Scorcher]

44 minutes ago, Cavehill Snow said:

As impressive as it is, the extreme cold has probably powered up the jet at just the wrong time for us. I know that some have said that in February it is possible for NE US/ Canada & ourselves to be cold simultaneously, however it is the depth of cold temperatures as the PV hits the Atlantic that has proven just too strong for heights to hold over here.

Agreed, a lot of people are getting carried away in here- nothing unusual in winter though of course! It's funny how summer is so different in here- people seem to be cautious and pessimistic at first about hot spells- in winter it's the opposite.

There is far too much energy coming into the Atlantic into the middle of next week for this proper cold to be sustained into the weekend and beyond in my opinion.

Areas in the far north and east of the UK may well hold onto the cold for a fair bit longer than the rest of us as those weather systems head towards our shores from the west. 

I can see a potential scenario where we go from cold and snow to very springlike conditions in the space of a few days- the latest run from the GFS shows this possibility.

[johnholmes]

Obviously some of you cannot read

This is the model thread not the Met forecast thread PLEASE!"

[Howie]

Just now, Scorcher said:

Agreed, a lot of people are getting carried away in here- nothing unusual in winter though of course! It's funny how summer is so different in here- people seem to be cautious and pessimistic at first about hot spells- in winter it's the opposite.

There is far too much energy coming into the Atlantic into the middle of next week for this proper cold to be sustained into the weekend and beyond in my opinion.

Areas in the far north and east of the UK may well hold onto the cold for a fair bit longer than the rest of us as those weather systems head towards our shores from the west. 

I can see a potential scenario where we go from cold and snow to very springlike conditions in the space of a few days- the latest run from the GFS shows this possibility.

So no chance for this to change? Why do the Americans always have to steal our cold from us

[carinthian]

7 hours ago, carinthian said:

Anyway back to the shorter more reliable time span, the chart below shows an interesting feature. That front across Southern Northern England could produce a prolonged snow event along the boundary zone as the very cold Arctic Continental flow undercuts. The fax charts seem to hold it in that location for at least 12 hours before sending southwards on Sunday.  See what the outer parameter results from the snow computer shows later this morning. Yesterday , it did flag up that zone. Could be an interesting day for snow predictions for this weekends event to unfold. Think quite an intense cold spell to evolve for you guys. How long ? Should get an update later from the team.

Good morning from a mild Alps.

C

Afternoon, sorry a bit late with an update. The team have provided the results for the outer parameters from the snow forecasting computer. The fine mesh model is unable to provide depth as far out as the British Isles but flags up snow prospects and locations for SE Britain.  Snow prospects good across the Southern Half of Northern England , especially Saturday evening into early Sunday. The band of snow then focused further Southeast during Sunday. Monday appears to show convective snow shower activity quite widely across much of Eastern Britain with some extending further west. Tuesday could be the surprise day as their charts indicate some sort of disturbance in the flow from the Low countries with snow prospects being flagged up more widely for a time ( Humber to IOW ). All in all good prospects for some snow for many but surprises can occur almost anywhere. Longer term, a swift removal of the Ac  to a more maritime air type likely to be less progressive across the north. However, thats still some days off . Just enjoy the snow and real cold whilst its here, at least for you lot in blighty.

C

[MattStoke]

17 minutes ago, sheikhy said:

That than then gfs is right and ecm is wrong in keeping the cold in place!!!!where ecm might be correct  is the cold fighting back after!!!expect a more mild push at 144 hours on 12zs!!hope not though!!

It doesn’t  suggest a mild push like that on the GFS. It suggests fronts dying across the south west with some snow before it just turns milder everywhere as winds switch to a south westerly. More like the UKMO.

Edited February 5, 2021 by MattStoke

[Don]

49 minutes ago, Scott Ingham said:

Theres no doubts there are increasing signs in both suites of the +AAM effects from the 13th peak kicking in. 

The big question is will it be enough to extend the cold or will it be too late and mean a 3 or 4 warm up before back in the freezer?

Im 50/50 on both options this morning with the gefs and 500mb charts in particular keen for a breakdown by the weekend

Unfortunately there is growing support now for a warm up and the latest Metoffice forecast highlights this.  I wonder if we will go back cold now as once the jet fires up, it maybe too much for the blocks to reform even with the AAM and MJO favorable? 

[Updated_Weather]

It just baffles me people never learn when model watching.. imaging to my belief when GFS wants to return to a more spring like set up.. is it likely? Who knows.. but again people are seeing day 10+ charts and thinking it will come off like that..

relax, the cold spell hasn’t even happened yet..