Model output discussion 11/12/21

[Allseasons-Si]

On 12/12/2021 at 18:51, MATTWOLVES said:

Ok folks I've decided I'm getting the drinks in for all of us this Xmas....

Now I'm gonna breakdance...

Could i have one on ice please Matt

 

ECM at day ten is looking super to me and i bet that there would be a reload from the NE looking at that,great set of outputs this afternoon,...the high is set now,that's step one,...step two is to build it sufficiently north to allow for cold feed underneath the high,...step three,...well we hope for retrogression of the high then a poss reload,....that's my dream anyway

oh!!!,....and check out that black hole anomaly

 

 

[Mike Poole]

5 minutes ago, northwestsnow said:

And...

There we have it.

EC on board...

❤

 

Not just on board, but leading the pack.  I’ve been saying for some days now that the key is WAA up the western coast of Greenland.  

And ECM has this right on, at T144:

To cement this, we need the low marked X to diminish in intensity (it seems to me that it has been on recent runs), if that happens then so will the Greenland high, in my opinion. 

 

[Bobd29]

Ok looking good but METO extended not on board yet, wait their next update before getting carried away. Happier when METO and ECM are aligned, another day or so maybe.

[LRD]

What a suite of 12z runs. I reckon even UKMO (the least favourable for cold tonight) would eventually build pressure somewhere to our North, NW or NE but just do it more slowly

But let's not forget that tomorrow could bring less positive runs but it might not mean it's the end of any wintry potential. The eventual fate of this High pressure building from the south over us will be a tricky one to forecast so let's not despair if tomorrow is not looking as good

Some of the posts last night were bizarrely negative... and from some experienced posters too, which was surprising

Edited December 12, 2021 by LRD
Typo

[northwestsnow]

Just now, Bobd29 said:

Ok looking good but METO extended not on board yet, wait their next update before getting carried away. Happier when METO and ECM are aligned, another day or so maybe.

It's a fluid picture..

Today has seen a swing to cold ..

Upgrades anticipated tomorrow...

( nothing is a a given of course, but things looking very interesting now ).

 

[Kasim Awan]

On 11/12/2021 at 19:11, Kasim Awan said:

I think the ECM may just be playing catchup and I fully expect it to resolve in the next 36 hours or so, by which time it will have joined the gfs control & gem in a clean push of heights towards Svalbard & cold into central Europe.

@ICE COLD seen as you're the first at it ❄Well, a truly pleasurable evening of model watching for all of us. I can't see any decent chance of downgrades at this stage, given the cross model pivotal changes seen recently.

[Chesil View]

5 minutes ago, northwestsnow said:

It's a fluid picture..

Today has seen a swing to cold ..

Upgrades anticipated tomorrow...

( nothing is a a given of course, but things looking very interesting now ).

 

They certainly are Nws.

The models have ebbed and flowed this week between colder and milder outcomes with the high. 

It's good that as the time gets closer they seem to be firming up more towards a  wintry outcome. As you say nothing is a given just yet, but the fact that the colder outcomes tie in well with background signals like mjo always lends a tingle of excitement.to the model watching.

[keithlucky]

7 minutes ago, Bobd29 said:

Ok looking good but METO extended not on board yet, wait their next update before getting carried away. Happier when METO and ECM are aligned, another day or so maybe.

Met seems to be on board.As HP moves north next weekend we begin to drag a North easterly feed  .Interesting to see temperatures in Sweden fall towards next weekend.

[MHW21]

9 minutes ago, northwestsnow said:

It's a fluid picture..

Today has seen a swing to cold ..

Upgrades anticipated tomorrow...

( nothing is a a given of course, but things looking very interesting now ).

 

Genuine Question. Why are we anticipating it to be upgrades? I know it’s been the direction of travel thus far, but surely it could as easily go the other direction.

[That ECM]

On 12/12/2021 at 19:20, MHW21 said:

Genuine Question. Why are we anticipating it to be upgrades? I know it’s been the direction of travel thus far, but surely it could as easily go the other direction.

Yes of course it can.  

[stodge]

Evening all

The mood has lightened here somewhat after the 12z output. ECM reminds us cold air can find its way even without a storm force E'ly and a 960MB LP in the Channel.

Many of the other model outputs suggest a period of cold conditions around the Christmas period - not surprisingly, longevity and severity still very much to be resolved.

This morning's 6Z GFS showed how inversion makes nonsense of the 850s and promotes ice days. 

We aren't there on the GFS 12Z OP but still seasonably brisk in the run up to the big day - note the warmth in the Southern North Sea:

 

[ICE COLD]

3 minutes ago, Kasim Awan said:

@ICE COLD seen as you're the first at it ❄Well, a truly pleasurable evening of model watching for all of us. I can't see any decent chance of downgrades at this stage, given the cross model pivotal changes seen recently.

Lol . I really do think we could get something note worthy out of this and what’s best of all is it’s over the Christmas period .

[Mike Poole]

2 minutes ago, MHW21 said:

Genuine Question. Why are we anticipating it to be upgrades? I know it’s been the direction of travel thus far, but surely it could as easily go the other direction.

Let the trend be your friend.  It was always said here back in the day.  Once the models start to catch the drift of the actual weather then they trend towards it.  There is a corollary too, when the models have the wrong signal they tend to lose it very quickly.  I think we’re in the first scenario on this one, and would expect the trend to true northern blocking to increase (Greenland not Scandi) over the next couple of days, but, please, give the 0z runs a chance of a wobble, before writing the whole thing off!

[amlb]

6 minutes ago, stodge said:

Evening all

The mood has lightened here somewhat after the 12z output. ECM reminds us cold air can find its way even without a storm force E'ly and a 960MB LP in the Channel.

Many of the other model outputs suggest a period of cold conditions around the Christmas period - not surprisingly, longevity and severity still very much to be resolved.

This morning's 6Z GFS showed how inversion makes nonsense of the 850s and promotes ice days. 

We aren't there on the GFS 12Z OP but still seasonably brisk in the run up to the big day - note the warmth in the Southern North Sea:

 

Given this comment on the warmer temps in the Souther North Sea, can you clarify the significance of this?

cheers

 

 

[Frosty.]

Have I missed anything..?..apart from the last 100 pages…  …anyway, although I’m a part timer on here now, the ECM 12z day 9 and 10 piqued my interest for sure!…I feel the best chance to arrive at a cold festive period is from an anticyclonic spell.. short term pain = long term gain…hopefully!

 

Edited December 12, 2021 by jon snow

[Catacol]

Excitement levels building a bit. A long way to go, plenty that can go pear shaped….but our first chance of proper cold for the season. This chart for me is the most interesting of the afternoon

Note the jet streak coming out of Asia as a +EAMT engages with the atmosphere. That jet streak is set to run into a North Pacific ridge already building due to MJO forcing, and enhanced quite possibly by the storm/typhoon coming east to west through Indonesia as flagged earlier in Twitter by Eric Webb. I’ll leave the interested to run the successive slides from here….but essentially pacific momentum barrels through to the US leading to this on Xmas Eve - all courtesy of that torque event on top of MJO support.

Notice the sharp NW to SE angle of a powerful jet streak heading into the Atlantic, engaging with a profile that is already amplified with a clear signal for a U.K. ridge toying with a shift north. To my eye GFS modelling goes all a bit haywire at this point, not surprising as it is approaching 300h….but if the medium range take on the pacific jet is correct then that NW/SE Atlantic jet axis will help propel the block to the north, with an almighty shunt.

Worth watching developments in the Pacific closely through this week. This FI GFS end point for the days after Xmas I think is definitely possible.

[minus10]

3 minutes ago, jon snow said:

Have I missed anything..?..apart from the last 100 pages…  …anyway, although I’m a part timer on here now, the ECM 12z day 9 and 10 piqued my interest for sure!…I feel the best chance to arrive at a cold festive period is from an anticyclonic spell.. short term pain = long term gain…hopefully!

 

Nice to have you back mate. Todays exitement although good is not the same without your input...

[DOdo]

Patience is a virtue, Still my bet is on an Easterly and  possibly  a White Christmas, Many more swings and turns to come of course but I am quietly confident that the goods will show

[StretfordEnd1996]

7 minutes ago, DOdo said:

Patience is a virtue, Still my bet is on an Easterly and  possibly  a White Christmas, Many more swings and turns to come of course but I am quietly confident that the goods will show

Some great looking charts tonight but I'm still a little on the pessimistic side as it stands right now in terms of 'White' Christmas - (or indeed snowfall of a notable extent at any period in the next 1-2 weeks) .. all depends on the location of the high etc.

As ever with a more Easterly influence precipitation is often somewhat limited but it depends on a number of things..

 

[LRD]

ECM op is an 850s outlier at Days 9 and 10

But in this scenario, 850s don't tell the whole story. Will be interesting to see the clusters later

Edited December 12, 2021 by LRD

[Mike Poole]

ECM clusters, and as interesting things are getting in closer in time, here’s the T120-T168:

Blocked.  Can’t see the difference between the 5 for the UK, high pressure in control.

T192-T240:

Heights migrating to NW on clusters 1 and 2, otherwise as you were.

T264+

Cluster 3 is my favourite, in a bookies sense, of Greenland high ridging to Scandi (12 members), but neither of the others let anything horrible in from the Atlantic.  But the models are struggling to getting to grips with an unusual situation, and from what I’ve seen tonight on the op runs, I would expect any movement on subsequent suites would be towards, rather than away from,  cold UK synoptics.   

 

[TSNWK]

Just been thinking to a couple of weeks back when ECM dished out some crackers around day 9 and 10 for a day or so.  Is there anything this time round to introduce a little more confidence that ECM is not stringing us along again 

[That ECM]

Ukmo not on board yet. This isn’t nailed on by any means. It’s been a good evening but let’s get past Tuesdays 12z.

Edited December 12, 2021 by That ECM

[syed2878]

38 minutes ago, Bobd29 said:

Ok looking good but METO extended not on board yet, wait their next update before getting carried away. Happier when METO and ECM are aligned, another day or so maybe.

  Exactly I totally agree until Exeter is on board I will keep my feet firmly grounded I remember the ECM back in 2012 The easterly saga T72 yet the next day it all imploded the easterly that never was. Still have nightmares about that particular ECMWF episode.

[phil nw.]

A promising ECM mean at tt240hrs -850s-European view

That cold from the east getting very close.If that Scandinavian trough broadens a little more we could well be seeing deeper cold across us by Christmas.