Model Output Discussion - the cold has arrived

[saintkip]

1 minute ago, Weather-history said:

High pressure seems to be favoured by GFS 0z ensembles for the following weekend. See if this gains traction, might be a slow ebbing away of the cold spell

That would be a dreadful way to end the cold spell, not even a snow to rain breakdown. A week of harsh frosts which for my job is a nightmare.

[Nick2373]

4 minutes ago, KTtom said:

From the evidence to hand, solid agreement for it to stay cold and dry for another week or so, best chance of anything more widespread regarding shower activity away from the north east around this time next week, before a powder puff change to less cold nextweekend.

Morning KTom how you are doing been trying to get back with you lot forgot my password lol, anyway I wouldn't give anything past five days in the model world for granted agree there's certainly a trend there. Looking at the output I think just above average temp wise, dry but this can change at any time. 

[Cheshire Freeze]

9 minutes ago, Weather-history said:

High pressure seems to be favoured by GFS 0z ensembles for the following weekend. See if this gains traction, might be a slow ebbing away of the cold spell

Yep.

Will be interesting to see if that anticipated E'ly begins to show up. We're getting hints

[Mark Smithy]

53 minutes ago, joggs said:

Ukmo looks decent but GFS a horror for prolonging this cold spell.

The GEM is the real horror show:

But that's at T240 and it's just one run.

UKMO still keeps up the cold but if you could roll on past T168 it looks like a movement west to east even with them.

GFS operationals are certainly going for a breakdown at present but there's still considerable scatter in the ensembles, even at short range, with some members showing milder conditions sooner than next weekend. Others take the UKMO route to prolonging cold.

The ECM will be interesting.

Next 24 hours may be make or break in the model outputs for how long this cold spell is going to last.

[Captain Shortwave]

This is probably the best charts this morning regarding potential snow.

 

A couple of disturbances developing on the northern flank of the low moving into France that could bring snow in from the east. Apart from this the output manages to avoid creating scenarios that are obviously conductive for snowfall away from direct coastlines. 

Edited December 9, 2022 by Captain Shortwave

[Mark Smithy]

Just taking a step back, the truth is that we don't really have proper blocking. Don't shoot me down for saying so but the easterly was a lot less pronounced than the models were originally suggesting, mainly because instead of a proper building Scandinavian High, we had low pressure in that region, pulling down a bitterly cold artic air mass. So we had an easterly flow for a couple of days, followed by a north-easterly veering northerly.

In the short term this made the cold spell a LOT colder but it may prove to be a Pyrrhic victory: a short term gain for a lot more pain.

What is absent from the latest models, in spite of Crewe Cold's aspiration, is a proper blocking high pressure build in the medium term.

[ItNeverSnowsInWindsor]

9 minutes ago, Mark Smithy said:

Just taking a step back, the truth is that we don't really have proper blocking. Don't shoot me down for saying so but the easterly was a lot less pronounced than the models were originally suggesting, mainly because instead of a proper building Scandinavian High, we had low pressure in that region, pulling down a bitterly cold artic air mass. So we had an easterly flow for a couple of days, followed by a north-easterly veering northerly.

In the short term this made the cold spell a LOT colder but it may prove to be a Pyrrhic victory: a short term gain for a lot more pain.

What is absent from the latest models, in spite of Crewe Cold's aspiration, is a proper blocking high pressure build in the medium term.

What’s also lacking is precipitation in the coming week due to slack isobars and no strong ridges.

[Kentish Snowman in Yorks]

The GFS short term ensembles (up until next Friday night) from the 0z run are again a sea of blue this morning.

Can we just get a bit of instability going that would turn the cold and dry theme into something more memorable?

[ItNeverSnowsInWindsor]

Meanwhile in Oslo the GFS 18z run shows predominantly below average 850s for the op.
 

Still in with a chance of a strong Scandi high at some point with all the cold pooling there not going anywhere.

Edited December 9, 2022 by prolongedSnowLover

[geordiekev]

16 minutes ago, Mark Smithy said:

Just taking a step back, the truth is that we don't really have proper blocking. Don't shoot me down for saying so but the easterly was a lot less pronounced than the models were originally suggesting, mainly because instead of a proper building Scandinavian High, we had low pressure in that region, pulling down a bitterly cold artic air mass. So we had an easterly flow for a couple of days, followed by a north-easterly veering northerly.

In the short term this made the cold spell a LOT colder but it may prove to be a Pyrrhic victory: a short term gain for a lot more pain.

What is absent from the latest models, in spite of Crewe Cold's aspiration, is a proper blocking high pressure build in the medium term.

We've got proper blocking in place but if anything the lack of the Canadian vortex is actually not doing any favours as you'd normally have moisture laden low pressure systems going up & over to form more of an omega block & heading down to Europe to set up Easterlies. I guess it's the main variable separating this from 2010

Edited December 9, 2022 by geordiekev

[Cheshire Freeze]

UKMO and ECM almost perfectly aligned at 120 hrs. Hard to see how GFS and GEM trump those two models.

[NewEra21]

Something still on for the SE Sunday into Monday...

 

[IanT]

The “get the cold in” crew have their wish. But the charts are reminding us that the cold - in itself - isn’t enough for lowland snow. It is a necessary pre-condition for a notable wintry spell, but it is no guarantee.

That said, small features can arise at short notice with outstanding results. All to play for in this regard, with attention better focussed on the detail in the next 168h rather than on predicting the breakdown somewhere out in FI.

 

[That ECM]

T168 not hard to see the difference. Lovely ecm.

[Ali1977]

Still cold out to 168 on the ECM, but there now seems to be cross model support for a breakdown in the cold by next weekend or at least a relaxation and pattern reset , will it be a snowy breakdown or is a flip is still up for grabs!! 

Edited December 9, 2022 by Ali1977

[sheikhy]

20 minutes ago, CreweCold said:

UKMO and ECM almost perfectly aligned at 120 hrs. Hard to see how GFS and GEM trump those two models.

They wont lol or they shouldnt!!also thats why i mentioned GEM can go in the cannon fodder box cos although its performed okay when it does stuff like last nights 12z you cant take it seriously!!especially when all other models are pretty much against it!!anywho ecm out to 192 hours and looks good so far!!!similar to its 12z run!maybe lack of snow again!!

[January Snowstorm]

Heights are gone by 192hrs to our North. Remains cold though and what pattern we stumble into next is very uncertain

I remember saying a few weeks back how there's was very little cold to our North. Wow deep purples now sustaining just to our North

Edited December 9, 2022 by January Snowstorm

[bluearmy]

Incidentally, i bet no one at icon had Morocco on their Azores low bingo card ………

the model is completely isolated on how it deals with the feature so the run has to be binned for now 

[Ali1977]

This would be Sod’s Law, a 10 day spell rarely above freezing then a breakdown with no snow. Thankfully FI is about day 6 , and till then we stay in the freezer

[January Snowstorm]

7 minutes ago, Ali1977 said:

This would be Sod’s Law, a 10 day spell rarely above freezing then a breakdown with no snow. Thankfully FI is about day 6 , and till then we stay in the freezer

Indeed but a glimmer of heights again over Greenland. As we know from Euro highs over recent years, patterns can often repeat and repeat over the course of winter

[Weather-history]

1 minute ago, Ali1977 said:

This would be Sod’s Law, a 10 day spell rarely above freezing then a breakdown with no snow. Thankfully FI is about day 6 , and till then we stay in the freezer

A lot of cold spells don't have snowy breakdowns.  Same way a lot of hot spells don't have thundery breakdowns.

[Chesil View]

Ecm op says goodbye to the current cold spell by 240 with the writing on the wall by 168.  However that is still FI for now.  Let's just hope synoptics closer to hand contrive to give some of us a decent snowfall between now and then.

[WINTRY WALES]

Just now, January Snowstorm said:

Indeed but a glimmer of heights again over Greenland. As we know from Euro highs over recent years, patterns can often repeat and repeat over the course of winter

Must be harder though for Greenland highs to repeat than euro highs?? 

[That ECM]

Hunting at T240 for a breakdown compared to hunting in T240 for cold. I know where I’d rather be.

[sheikhy]

8 minutes ago, That ECM said:

Hunting at T240 for a breakdown compared to hunting in T240 for cold. I know where I’d rather be.

Its hilarious!!some of us are so desperate for mild we start mentioning charts at 240 hours!!!when there is cold those comments are no where to be seen lol!!anyway i hope we see some snow before this does come to an end!!!