Model Output Discussion - the cold has arrived

[Jake March-Jones]

7 minutes ago, phil nw. said:

Yes there is evidence of a more typical pattern coming at least for a while.

I posted in the Strat thread a couple of days ago of the warning signs .

 

Ah sod it then... Let's just meet back here next year. 

 

 

[Derecho]

1 minute ago, BLAST FROM THE PAST said:

Not this month yet (but NW had coldest November for 4 decades) but over recent previous months date records have usurped warm records by a considerable amount, but that looks potentially likely to change very soon for Dec.  Very interesting watching.  And it’s Arctic air so if the Arctic is so ‘warm’ anomalously one has to ask how the cold that is going to flood down is potentially record breaking?  Arctic outbreaks happen so how come will this one potentially break records? Genuine query here.

 

BFTP 

A few date records here and there in November yup but the likes of November 2000 in western USA and November 2006/2012 in western Canada were colder.

What is making the cold spell over North America so strong is the fact that the atmospheric circulation pattern is so extreme. You've got an 1060mb high in the Arctic maintaining its intensity as it moves south. The 850s therefore face little moderation going straight over a continental area because the airmass is moving south so fast.

The uppers over the Arctic may be a degree or 2 warmer then in previous decades but if you get a cold pool and an extreme atmospheric circulation pattern tapping into it, you can still get cold extremes.

It's like the beast from the east in March 2018, if you get an even more extreme cold atmospheric circulation pattern you can still beat cold records but that extra heat circulating around our globe will be elsewhere.

I am critical of those who think cold winters will become a thing of the past, like the ludicrous claim from the MO that ice days will become a thing of the past. If our weather variations are becoming more extreme... then we will beat warm records by a larger margin (December 2015 as an example) but still beat cold records.

Lets just hope at some point we can get one of those cold extremes for us, the last 2 weeks have been a nice try but it was just a surface cold pool building after a period of relatively cold uppers coming in after last weeks northerly.

Good question though.

[steveinsussex]

9 minutes ago, Speedbird said:

 

This is the tweet I was referencing . . .

But Marco was quoting Cohen

[Jake March-Jones]

21 minutes ago, TSNWK said:

Yep.. why is he not credible? Met office? And tweeted correctly about this weekend breakdown 8 days ago 

Did I say he wasn't credible? 

[TSNWK]

1 minute ago, Jake March-Jones said:

Did I say he wasn't credible? 

No. I was asking that anyway was a nice sidebar whilst we wait forbtge 18z.. be nice to see the op follow one the 12z perbs that were breaching -10 Christmas weekend

[Battleground Snow]

15 minutes ago, nick sussex said:

It’s closing off the high over ne Canada and west Greenland . And the changes to get to that point started within T96 hrs .

 

It does indeed look more wedgy in the right places.

I think that's the best we can hope for over  Xmas week, the pattern just enough south the allow snowfall somewhere, most likely northern UK at this point.

After that we are looking for euro heights to relax when the mjo moves away from phase 4 and 5. Notably the gem is the fastest into 6 and 7

Potentially the USA cold blast may provide some WAA up the west coast of Greenland if we get lucky.

 

Edited December 16, 2022 by Battleground Snow

[Jake March-Jones]

4 minutes ago, TSNWK said:

No. I was asking that anyway was a nice sidebar whilst we wait forbtge 18z.. be nice to see the op follow one the 12z perbs that were breaching -10 Christmas weekend

Ha... Maybe. But maybe we will come crashing down to earth? 

 

[The Enforcer]

19 minutes ago, Speedbird said:

 

This is the tweet I was referencing . . .

I think all I need to know here is that the data source in this and the other tweet is GFS at a range >14 days. Pause for laughter and move on.

[bluearmy]

Regarding the strat coupling - the upper strat will be approaching record strength in week 2. I find it inconceivable that the modelling will not show this strength downwelling towards the trop - gfs ops have been showing this. The question is does it actually make it far enough down to affect the trop and if it does, at what latitude does it affect the NH. I expect  that trop patterns will still hold sway and if the strength works down then HLB in place will be not be blown away.  Additionally, there is the question as to how well the ens will model the strat and its interaction with the trop.

I think this adds an extra piece of uncertainty into the nwp.  to be fair to the ens, the modelling is following the extended ens as it ticks down but I have no faith that we aren’t going to see a change for week 2 against what is currently being shown. 

[blizzard81]

The news about the strat/trop coupling doesn't surprise me in the least as we approach January. I am astounded at the lack of cold during January's in the UK over the last 30 plus years. It should be deep mid winter but it delivers nothing. Just imagine if we had never experienced any decent warm spells in July over the last few decades. 

[BLAST FROM THE PAST]

20 minutes ago, Quicksilver1989 said:

A few date records here and there in November yup but the likes of November 2000 in western USA and November 2006/2012 in western Canada were colder.

What is making the cold spell over North America so strong is the fact that the atmospheric circulation pattern is so extreme. You've got an 1060mb high in the Arctic maintaining its intensity as it moves south. The 850s therefore face little moderation going straight over a continental area because the airmass is moving south so fast.

The uppers over the Arctic may be a degree or 2 warmer then in previous decades but if you get a cold pool and an extreme atmospheric circulation pattern tapping into it, you can still get cold extremes.

It's like the beast from the east in March 2018, if you get an even more extreme cold atmospheric circulation pattern you can still beat cold records but that extra heat circulating around our globe will be elsewhere.

I am critical of those who think cold winters will become a thing of the past, like the ludicrous claim from the MO that ice days will become a thing of the past. If our weather variations are becoming more extreme... then we will beat warm records by a larger margin (December 2015 as an example) but still beat cold records.

Lets just hope at some point we can get one of those cold extremes for us, the last 2 weeks have been a nice try but it was just a surface cold pool building after a period of relatively cold uppers coming in after last weeks northerly.

Good question though.

Thanks for informative reply Q, appreciated

 

BFTP

[love snow in winter!]

5 minutes ago, The Enforcer said:

I think all I need to know here is that the data source in this and the other tweet is GFS at a range >14 days. Pause for laughter and move on.

Exactly. One day we say gfs is thr worst kf the bunch and next day write of the winter in the back of it . Anyway Marco am sure has a firm dislike for the cold stuff. 

 

Truth is , we have to wait and see. 3 weeks into the winter guys !

 

[Snowmadsam]

After taking a tumble on the ice today, I’ve change my mind I want all model output to be mild

 

BRING ON THE BLOW TORCH! 
 

(sadly no luck with another colder spell) 

[TSNWK]

So primed to drop a Cross polar flow over us.. if we can just keep on building those mid Atlantic heights..annoying as it looks feasible but you kinda now the outcome with other models and previous runs. But we still crack on.

[MJB]

1 hour ago, fromey said:

Actually it was 

LOL and the original post said early January onwards , whereas JC's comment is ............early January . 

Enough said 

[Scandinavian High.]

1 hour ago, Speedbird said:

 

This is the tweet I was referencing . . .

Didn’t they say the same in November stating beginning of December Strengthening polar vortex didn’t happen we went in to freezer.

Edited December 16, 2022 by Scandinavian High.

[Ali1977]

Here’s the Atlantic WAA link up at T168 - hopefully a better outcome 

[Day 10]

Nudge the whole pattern south and east and it's a belter!

[Ali1977]

C’mon, surely this ends up good  No doubt the Greeny heights will sink before pushing everything to our East

Edited December 16, 2022 by Ali1977

[Battleground Snow]

Just now, Ali1977 said:

C’mon, surely this ends up good

Blow them euro heights away and unleash the polar air from the North 

[TSNWK]

1 minute ago, Ali1977 said:

C’mon, surely this ends up good

Just think the euro heights being pumped up by the trough we want to move south east will scupper it.. chicken & egg catch 22

[January Snowstorm]

Get the heights into Greenland and the rest will fall into place. Better run

[saintkip]

6 minutes ago, Scandinavian High. said:

Didn’t they say the same in November stating beginning of December Strengthening polar vortex didn’t happen we went in to freezer.

They are hopeless, for some reason people hang on there every word as if it’s gospel. They change as often as the models.

Best prediction for UK winter especially the South is mild and wet.

[TSNWK]

And there you have it 12 hours later the trough can’t force the euro heights and will now set to south west waving at us for a while until it fills..

1 minute ago, January Snowstorm said:

Get the heights into Greenland and the rest will fall into place. Better run

Upstream is not really the issue in my view and has not been for several days of modelling. It’s downstream and how the heck to bin off those euro heights 

[johncam]

1 minute ago, TSNWK said:

And there you have it 12 hours later the trough can’t force the euro heights and will now set to south west waving at us for a while until it fills..

Yep GFS following the ECM