Model output discussion - Winter has arrived

[matty40s]

It will be interesting to see if this has an effect on us in a few days, the jetsream split is providing the forcing for the east coast storm.

 

[Weather-history]

15 minutes ago, mb018538 said:

This is so frustrating! Too early and there isn’t enough cold to tap into, and too late and the sun is too strong and melts any snow. Please let us have something late December to early February in the sweet spot!

It wasn't this time 10 years ago....and that's the point. It isn't too early, the problem is there is no deep polar airmass to tap into.

[captaincroc]

3 minutes ago, CreweCold said:

Good to see you back for another year in the madhouse Ben!

I see your interest has been raised as much as mine with regards to the output. Still jealous you have height on your side these days though!

Maaaate! Good to see you too. The elevation has been a godsend the past few years.  Wet 'non sticking' snow in Crewe means sticking up here,  a few times I have spoke to the folks back home and then say it's only sleeting/wet etc.  A defo brew would be nice if you're up for it! haha. Yeah back..don't know why I do it? 

I agree, I've spotted it for a while...kept expecting it to be flushed away but kept creeping back..then these next few days have an essence of it (weak heights Sun-Weds...then if the ECM is correct then it properly nudges in.

[Rayth]

Does anyone know what happened to Bring Back 1962/63 ? 

[Kirkcaldy Weather]

10 minutes ago, General Cluster said:

Must admit chaps, I really see little to be despondent about: we've some of the best December synoptics, for years -- it's even snowed here!  And it must be the airmass that's doing it, because SSTs (in the North Sea) are quite substantially above where they'd normally be at this time of year...

And, I'd be surprised (should the blocked pattern persist, for any length of time) if deep cold doesn't soon start to show its hand, over Scandinavia?

Keep the faith!

I think that certainly  played a part here last night with the convection / thundersnow, current sea temps here  850 hpa last night was around -4 lowering to -2 so that’s about a 13/11 degree temperature difference and as u say should we get into a really cold easterly feed = North Sea snow machine in overdrive?  

Edited December 4, 2020 by Kirkcaldy Weather

[Daniel]

Ecm has maxes of 0c - 1c across most of the south on Monday

[TSNWK]

1 minute ago, Daniel said:

Ecm has maxes of 0c - 1c across most of the south on Monday

Chilly.. but is max for 6hrs up to 12. If there is 78 hour  we would include afternoon up to 6.00pn

[Cheshire Freeze]

5 minutes ago, captaincroc said:

Maaaate! Good to see you too. The elevation has been a godsend the past few years.  Wet 'non sticking' snow in Crewe means sticking up here,  a few times I have spoke to the folks back home and then say it's only sleeting/wet etc.  A defo brew would be nice if you're up for it! haha. Yeah back..don't know why I do it? 

I agree, I've spotted it for a while...kept expecting it to be flushed away but kept creeping back..then these next few days have an essence of it (weak heights Sun-Weds...then if the ECM is correct then it properly nudges in.

Always up for a coffee mate. Give me a nudge in the New Year (will be solid with work until Christmas)

Hopefully it'll be a snowy day

[danm]

This is what a c**p December chart looks like:

 

I’d much rather be in the position we’re in now with a big Russian high putting pressure on the TPV and hopefully setting us up for something much more wintry down the line. 

[Anthony Burden]

As Matt Hugo said this morning ECM 00 hrs being an outlier,seems to be correct regarding 

ECM latest chart,alternative low pressure tracks keeping U.K. in colder air at 6 days or more.

Very encouraging no budging that Russian high let’s hope for westward nudge ,bit by bit if

necessary.

[Daniel]

1 minute ago, TSNWK said:

Chilly.. but is max for 6hrs up to 12. If there is 78 hour  we would include afternoon up to 6.00pn

Warms up a little bit but no difference for places in the far south 

[MATTWOLVES 3]

1 hour ago, Jason M said:

I'd put the odds of that verifying as slightly below the odds of humanity making first contact with an advanced alien species at the same time scale . 

I tell you what, even though we've had some excellent analysis from Catacol today I feel a little trepidation in one or 2 posters regarding the coming Winter... Come on guys sooner or later the Atlantic may break through.. That's sods law!! But that's not to say it will gain a strangle hold for the next 3 or so months! There is a lot going on and things could very easily line up very nicely in the coming weeks... 

I'm gonna put a smile on you coldie faces, and let's hope we see many more of these in the coming weeks... All this talk of Aliens and that!!!!! Trust me in the words of the X Files...... The truth is out there...

[Methuselah]

4 minutes ago, Daniel said:

Ecm has maxes of 0c - 1c across most of the south on Monday

That chart makes me even more hopeful of catching a North Sea lightning display... I wonder how many nuclear bombs'-worth of energy is out there, just waiting to explode? Embra's Six-Five Special may be a sign of things to come??? 

[Uncertainty]

Is it fair to say it’s now the UKMO that’s out on its own this evening? 

The 12z big 3 ECM, GEM, and GFS all have very interesting NH profiles at day 10. This particular ECM frame has an Arctic high, amplification off the Eastern seaboard, a Euro trough and a huge retrogressing Urals high. Not what you would normally associate with mid December in recent years.

 

A presumption here, but I imagine the vast majority of viewers/posters on this forum would ‘take that’ if you were offered this chart for mid December. If you wouldn’t, would you rather have this vile offering?

Or this despicable effort?

 

I thought so!

Finally, another nugget from the treasure trove that is the freely available EC46 data.

The lime green dots represent the predicted position of the MJO at around day 20, many members reach phase 6, some return to the centre. Here’s the Nina-composite for phase 6

And the Week 4 anomaly

A continued signal for a Scandi-Greenland dipole.

And finally, fwiw, model watching has actually been ‘enjoyable’ in the last few weeks. It’s been great hearing so many posters, new and old, share their views, analysis and banter and it feels like many of us are “on board” for the prospect (and it is only a prospect at present, with the seasonal models still generally against the idea) of an exciting winter. 

 

 

 

 

Edited December 4, 2020 by Uncertainy

[Alexis]

17 minutes ago, Daniel said:

Ecm has maxes of 0c - 1c across most of the south on Monday

Due to freezing fog I suspect 

[northwestsnow]

EC mean has the Atlantic in charge as we move forward through next week...

[damianslaw]

Lots of variability in the models at present, making forecasting difficult. What looks most likely is a stalemate situation, trough unable to move east dud to the significant heights to our east. End result cold and unsettled with every chance of trough disruption. Indeed these are classic snow making synoptics, a pity we don't have a cold pool to draw from, though the continent should cool quite rapidly now, so would not rule out widespread snow within next week.

Longer term quite startling to see the PV shunted away from our shows and signs of heights building over Greenland, would not take much fof a link up of Russian and Greenland heights, just needs a deeper digging trough to go SE.. 

These are very different synoptics to many Decembers recently. All very interesting!

[Djdazzle]

Good that we don’t have raging zonality. But even so, something very cold still looks unlikely. It’s so much harder these days to get the right setup.

I can see this December being cold, but  we’d need a lot of luck for anything more.

[Scandinavian High.]

Just seen long range forecast they saying jet stream coming back in to play next week  low pressure to the north west.  but what I’ve seen tonight on models is low pressure going south east with Continental air coming from east what sort of models are they looking at .

[Sweatyman]

34 minutes ago, Daniel said:

Ecm has maxes of 0c - 1c across most of the south on Monday

is it drunk? Or will it mean mist n fog lingering?

[Tim Bland]

2 minutes ago, Scandinavian High. said:

Just seen long range forecast they saying jet stream coming back in to play next week  low pressure to the north west.  but what I’ve seen tonight on models is low pressure going south east with Continental air coming from east what sort of models are they looking at .

Whether it slides or not low pressure comes from the west and it’s not particularly cold. Neither ECM or GFS show any snow , just average to slightly below and rain.

[Fourty Point Three Degrees]

Out of interest what were the long range model forecasts showing at the start of December 2009? This was our last cold Winter that the UK saw.  Wonder if models were showing a mild and wet winter and it was just by luck we snapped into the cold pattern in Mid December in that year? 

[feb1991blizzard]

26 minutes ago, Uncertainy said:

Is it fair to say it’s now the UKMO that’s out on its own this evening? 

The 12z big 3 ECM, GEM, and GFS all have very interesting NH profiles at day 10. This particular ECM frame has an Arctic high, amplification off the Eastern seaboard, a Euro trough and a huge retrogressing Urals high. Not what you would normally associate with mid December in recent years.

 

A presumption here, but I imagine the vast majority of viewers/posters on this forum would ‘take that’ if you were offered this chart for mid December. If you wouldn’t, would you rather have this vile offering?

Or this despicable effort?

 

 

Or would you rather have a similar one to what we have now.

 

And where did that get us?

[Methuselah]

Well, I'm nae getting over-excited... but I remember December 1962: It was sleeting, not snowing, on the day of our Christmas Carol Service... Even in those days, snow before Christmas was seen as a 'bonus'... But, hey, that's not the point; the point is that it's always taken time for severe cold to develop. If it ever does?!

[stodge]

Evening all

For some, it seems, winter has arrived with a vengeance and if you've had or are having snow, kudos. As expected, nowt but cold rain here in lowland East London but there's more than a hint of winter about. :Last evening's output wasn't inspiring to my eyes suggesting the Atlantic would be back in the coming week but let's see where tonight takes us.

12Z GEM: - by T+96 the trough is still very much with us. An LP forming off the German coast deepens and moves NW across the North Sea to the north of Scotland while the trough extends south into Europe. The Atlantic doesn't inspire confidence for a prolonging of the cold spell at this time but the block is edging into Scandinavia. Initially, the Atlantic LP does draw up a milder feed but by T+168 the LP is stalling and filling and the bulk of the enrgy is now heading SE with a secondary feature crossing southern England.  By T+240, we end in a messy situation. Strong heights are developing to the north and north-west and the jet is heading south with a new LP slowly heading towards NW Europe. I note the cold pool over Scandinavia which is something we may (or may not) be able to tap into down the line.

12Z GFS - again, the Atlantic showed its hand on this model last evening. T+96 looks similar to GEM with the LP heading NW towards Scotland and maintaining the cold and unsettled theme. Things then start to get interesting as the next Atlantic LP splits with the main energy heading SE and developing quite a potent feature crossing southern Britain at T+156 - you'd think the Pennines and the Peaks might get some snow from it. By T+240 not much has changed - a succession of shallow LP head across southern Britain and again the northern hills might do well from that. There's a potent little storm in the Atlantic and heights to the NW. Unfortunately for cold fans, the Atlantic LP stalls and all it does is ridge the Azores HP north east so back come the SW'lies but by T+330 there are signs of disruption once again as the block to the east remains in situ. We end with renewed heights to the north of Scandinavia and a shallow feature over Germany providing a weak E'ly facing a renewed Atlantic push leaving the British Isles in a col. Signs again of a warming at the far end of FI at 10 HPA but I'm not convinced.

12Z ECM - let's see where this goes. The T+96 is fairly familiar but by T+168 the Atlantic looks set to take over despite the lowering of heights over Europe - or perhaps not. Once again, the bulk of the energy slips SE and we have an active LP crossing Southern England at T+240 with the trough negatively aligned through the British Isles into central Europe. Heights remains over Scandinavia and the enormous active PV of recent winters not really evident with heights over the Pole and in Russia.

12Z GFS Control looks very different to the OP in all fairness.

Conclusion - 3-5 days of cold and unsettled weather before a brief return to the Atlantic but we aren't talking deep LP barrelling past northern Scotland to Russia by any stretch. The "slider" still seems the form horse and GFS in particular plays this well. The tendency of that model to "reset" the Atlantic pattern cautions reading too much into FI but there seems a strong signal for heights over the Pole and into Russia offering the possibility of an increasingly frigid pool in Scandinavia. The problem for us is it may just be too far away and the trough sits across us so more rain though snow for northern low ground and higher elevations can't be ruled out as we move past the middle of the month.