Model Output Discussion - Into the new year

[Skullzrulerz]

1 minute ago, Frosty Winter said:

GEM 12z is also another decent run out to t162 so far, although not up to the same standard as the GFS. Great start to the afternoon though. These charts must be enough to crack a smile from @Skullzrulerz hopefully as well!

I must say it does look great seeing it 

But we need to see this be constant along the GFS instead of a one run wonder 

If the ECM goes along this route we should be okay 

I get excited once we have a agreement along the models but I would urge to be careful at the moment

[APerez]

Hello folks, it seemed the perfect time to create an account on here and get posting to help further my weather education. I'm hoping Mr Gaze can do the same thing for me over on T.W.O. 

Anyway, a really positive GFS 12z unfolding and hopefully one that returns the model to form after an iffy spell, especially for the operational. When the full ensembles come out later I expect this will be tucked in nicely with most of the suite rather than poking its head above the 0C threshold like some curious meerkat. Looking at the latter part of the run - post 240hr, it looks like we have low pressure drifting up from the south, ushering in less cold upper air but at the same time bringing precipitation that would be ripe for a battleground snow event with such entrenched and prolonged cold air (and ground) in place...

 

What entices me is the prospect of ice days in such a cold and slack setup. Having read through this thread pretty religiously over the past week or two the risks of freezing fog and hard frosts have been noted. Going into the New Year, conditions seem ripe for ice days given we would have had cold air in place for some time, with ever more slack conditions establishing...

Finally, what is most encouraging to me is that, though I'm posting charts in fantasy land, it's not like the short-term is mild and horrible. We're into this cold spell right now and, if anything, conditions going into 2021 look colder and colder still  

 

Alex

Edited December 27, 2020 by APerez

[Penrith Snow]

Just out of interest how cold does it have to be before we can call an easterly a BFTE, daft question I know but surely some of the output today would be borderline at least?

[Faronstream]

GFS 12Z looks extremely good synoptically but still a little meh over the 850hpa temps, need to get down below magical -12

[Ice Day]

That's hilarious - we've broken Meteociel 

[MJB]

Just now, Faronstream said:

GFS 12Z looks extremely good synoptically but still a little meh over the 850hpa temps, need to get down below magical -12

Why do we need to get below -12 850@s , that is totally wrong 

[andymusic]

Just now, Penrith Snow said:

Just out of interest how cold does it have to be before we can call an easterly a BFTE, daft question I know but surely some of the output today would be borderline at least?

nope that's a beast on the 12zs - once that north sea snow machine is up and running lol

[Speedbird]

3 minutes ago, Faronstream said:

GFS 12Z looks extremely good synoptically but still a little meh over the 850hpa temps, need to get down below magical -12

below -12 ???

Sorry, that's just totally incorrect and misleading.

Edited December 27, 2020 by Speedbird

[That ECM]

Gfs is brilliant. I like this though. As this gives credence imo.

[Stu_London]

1 minute ago, Penrith Snow said:

Just out of interest how cold does it have to be before we can call an easterly a BFTE, daft question I know but surely some of the output today would be borderline at least?

Id say a beast would be defined as a big scandi high and a trough dropping out of the arctic around it's southern flank. Not quite there - yet. 

[Radiating Dendrite]

3 minutes ago, Penrith Snow said:

Just out of interest how cold does it have to be before we can call an easterly a BFTE, daft question I know but surely some of the output today would be borderline at least?

I always think -10c 850s for the BEAST.

[Allseasons-Si]

WOW WOW WOW!!!

look at the mean so far

186

       

Edited December 27, 2020 by Allseasons-si

[weathertoski]

Dartmoor anyone?

[kold weather]

The models really are being very inconsistent at the moment, which would suggest to me that caution is needed, they could very easily swing back again tomorrow to what they showed yesterday.

With that being said I was a little suspect that the models were way over-correcting yesterday, and they often do that only to have to row back to a less extreme version of the previous pattern. Either way the models today have locked back onto a cold pattern and long may it stay that way.

As for tomorrow 's possible snow, its going to be a nowcast, even at this point there are considerable differences. Could well be some surprises as well as little trough/frontal features can pop up at very short notices in these sorts of set-ups.

With a reasonably cold surface from now on, our range of options for snow should increase, especially the longer it holds and the more it drags surface/sea temps down.

Edited December 27, 2020 by kold weather

[Faronstream]

1 minute ago, Speedbird said:

below -12 ???

Sorry, that's just totally incorrect and misleading.

I mean for really wintry wise conditions, not about what you need for snowfall.

[Battleground Snow]

Still going strong at the end of the run, the pattern seems to always want to re-amplify over eastern Canada. If this keeps happening could be a long period of below average temperatures

 

[Weathizard]

When the wind direction is East 850’s don’t even need to be -5 to deliver widespread snowfall, in fact some of the biggest snow events in recorded history have been with uppers that are only just below freezing, air sourced from the east means it’s drier, lower dewpoints and less modification.

[Penicuikblizzard]

18 minutes ago, Steve Murr said:

Now then ....

Be prepared for some awsome ENS over the next few days.

If Screaming Easterlies are your thing...

Vertical ridging in the atlantic - ( loop ) which screams southwards through Scandi > classic classic easterly

I can sense your excitement building, that screams potential

[Zak M]

(Almost) Countrywide snow on the 12z GEM...

[MJB]

1 minute ago, Weathizard said:

When the wind direction is East 850’s don’t even need to be -5 to deliver widespread snowfall, in fact some of the biggest snow events in recorded history have been with uppers that are only just below freezing, air sourced from the east means it’s drier, lower dewpoints and less modification.

Agreed , we are fixated with -10's and below for some reason

[Speedbird]

Just now, Faronstream said:

I mean for really wintry wise conditions, not about what you need for snowfall.

Well that's somewhat subjective but you can see why your initial post was challenged.

[Howie]

1 minute ago, Battleground Snow said:

Still going strong at the end of the run, the pattern seems to always want to re-amplify over eastern Canada. If this keeps happening could be a long period of below average temperatures

 

A milder blip before another cold plunge from the North, perfectly fine by me

[Stu_London]

2 minutes ago, Allseasons-si said:

WOW WOW WOW!!!

look at the mean so far

186

and just watch the scatter for the long ensembles - some might go over +5 - others might be close to -15

[Jason74]

I'm still not allowing myself to get too drawn in by the charts. 

[Ice Day]

2 minutes ago, Allseasons-si said:

WOW WOW WOW!!!

look at the mean so far

186

They really are great - make no mistake, these are a major upgrade

I have a -10 850's showing for just 165hrs!  Stunning output