Model discussion - hunt for cold - Christmas countdown

[MATTWOLVES 3]

1 minute ago, Midlands Ice Age said:

Thanks for replying...

I have back winded it and they are forecast that the high to our North West (Griceland) is shown to be draining away across us,  in 2days time,  and for it to be sitting in Italy by Xmas!!

Furthermore they have the low in the Atlantic as a massive feature (covering 3/4 of it), with fronts approaching the SW by Thursday. The were forecasting rain for Xmas day, but suggested if you want snow that it may turn to snow over the Grampians, so a long journey was required.

Without charts they then stated that some models were showing that it may turn to snow after Boxing Day.

I did not see the overnight runs last night.   Are they still using those?

I had seen before that they use the ECM and presumably would not have been able to include the latest ECM. So was this forecast 18:30 (BBC1)  based upon the ECM from 00z last night?.

Incredible if true.

MIA

I've heard it said before mate,but I can't pass it off as true.. being as the ecm 12z was running when that broadcast was covered I would say its highly unlikely that the 12z would have been referenced too.

Perhaps a blend of the ecm 0z and ukmo that started earlier! And I wonder if they are using any of the data from mogreps now? They seem to be sitting on the fence alot these days,and for me they seem to go out of there way to bring a different forecast than Exeter...almost sounds like point scoring I know!

[northwestsnow]

23 minutes ago, mulzy said:

MOGREPS 60/40 for cold/mild for London 26th-28th.  Trending the right way!

Great news mate thanks for the updates in these topsy turvy times.

I've thrown that many towels in I need to go and purchase some more !! 

[tight isobar]

15 minutes ago, mulzy said:

Early view of eps up to day 9 is underwhelming - nowhere near as good as the gefs.  Disappointed!

@disapointed!- don’t be.. the America model is the sober 1 within 0-/144 hrs.. you’ll see this opening up through nxt 2/3 suits in raw 

[SqueakheartLW]

With all of the models now out I shall be able to make a direct comparison to those that were out at this time yesterday and see how they have changed compared with 24 hours ago on the battleground Christmas scenario and where the most likely snow zone is favoured to be today

Summary of yesterday's model update

Yesterday the models came out in this order with the most northern battle zone at the top of the list and the most southern at the bottom

North Battle Zone

1     GFS 12z (19/12/2021)     Scotland Battle Zone

2     CFS 06z (19/12/2021)     Scotland Battle Zone

3     GEM 12z (19/12/2021)     Scotland Battle Zone

4     ECM 12z (19/12/2021)     N England Battle Zone

5     ICON 12z (19/12/2021)     N England Battle Zone

6     NAVGEM 06z (19/12/2021)     Midlands Battle Zone

7     JMA 12z (19/12/2021)     Midlands Battle Zone

8     UKMO 12z (19/12/2021)     Southern Battle Zone

South Battle Zone

Summary of today's most recent output

Now I shall go through each of the 8 models I featured yesterday and see how they compare and how they have moved up or down the north to south list in general and whether the shift is overall northwards, southwards or on average about the same averaged out across all the models.

1     ICON 12z (20/12/2021)     Up 4 positions

Today the ICON has decided to be the bad ass of the models and comes out top of the pile in terms of having the battle zone the furthest north. Only NE Scotland has any real chance of snow here for Christmas Day on this run, bad ICON, bad bad ICON.

2     CFS 06z (20/12/2021)     Same position as yesterday

CFS has really maintained its Scotland battle zone status from yesterday and would have come out as the bad ass most northern option if it were not for the dire performance by the 12z ICON. CFS was saved by the ICON but one thing I can say in favour of the CFS is at least it has been consistent so far in where the battle will be taking place unlike other models.

3     ECM (20/12/2021)     Up 1 position

The ECM has been a mover in the wrong direction and has taken the battle zone out of Northern England and more into Scotland today, naughty ECM, how could you. Hope it can shift back southwards in tomorrows 12z update.

4     JMA 12z (20/12/2021)     up 3 positions

The JMA has been the other big mover in the wrong direction today and has taken the battle zone from the Midlands into Northern England, bad JAM, very bad JMA. So far lots of movers north but have any models taken the battle southwards.

5     NAVGEM 12z (20/12/2021)     down 1 position

NAVGEM has maintained consistency here with keeping the battle zone very much in the Midlands again but due to other movers has somehow dropped a position further southwards on the list. Not an improver as such but at least keeps us in the game.

6     UKMO 12z (20/12/2021)     up 2 positions

UKMO, you are such a let down after yesterday when you had the whole of the UK very much in the cold air. At least UKMO didn't perform any more worse like some others higher up the list and has kept most of the UK in the colder air.

7     GEM 12z (20/12/2021)     down 4 positions

Now onto the two big models I consider the Christmas heroes today. The first is the GEM which has very much kept the Midlands in the game here and if anything this is also a slight upgrade on yesterday's 12z with colder air in play too. Keep it up GEM.

8     GFS 12z (20/12/2021)     down 7 positions

Last and by no means least, especially today is the big mover in the coldies favour, the GFS. The GFS is my big Christmas hero today, strange that I would be so complementary of the GFS but today it has done what I could only call a big U turn and has gone from most northern option yesterday to most southern option today. Hope it can stay there now and help pull the others down to the south with it.

[Grimplet]

8 minutes ago, MATTWOLVES said:

Yep..we should be getting tonight's update come Friday

Looks likely that this won't be sorted now til Wednesday...I think we should be much more confident on the outcome by then.

Then the Beeb should know by new years eve what's going to happen Christmas day.

[Kasim Awan]

We'll know by 18z wednesday

[Midlands Ice Age]

6 minutes ago, Grimplet said:

Then the Beeb should know by new years eve what's going to happen Christmas day.

Clearly rapid Climate Change will be the cause.

MIA 

[The Eagle]

Pity we couldn't have the ECM really add to a wave of convergence this evening which keeps us all guessing.

It has moved in the right direction but not enough and I'll be hoping for better tomorrow.

[iowpompeylee]

Really good to see a few more stamps with the low south of the uk on Xmas day, happy to see the mogreps starting to trend colder. Hear all the time about how highly rated they are. 

Edited December 20, 2021 by iowpompeylee

[TSNWK]

Wow this place is electrically charged this evening.  Even  between runs we have posts mogreps improve and then in  the blink of eye it's all taken away by reports of a poor ECM essemble suite.. 

I'm going for a 10 min nap . Before ec46 that will generate debate before we start over with 18z..

[The Eagle]

4 minutes ago, iowpompeylee said:

Really good to see a few more stamps with the low south of the uk on Xmas day, happy to see the mogreps starting to trend colder. Hear all the time about how highly rated they are. 

Remember that's max temperature as well.

[sheikhy]

Ecm mean ever so further south?!

[Lincstim]

Which run is the best for maybe not getting the white Xmas but bringing the BIGGER chance of either going into the freezer (I'll take a cold fridge ) and bringing a better snow event or prolonged cols spell 

 

[swfc]

7 minutes ago, Lincstim said:

Which run is the best for maybe not getting the white Xmas but bringing the BIGGER chance of either going into the freezer (I'll take a cold fridge ) and bringing a better snow event or prolonged cols spell 

 

At the moment even if the Xmas cold lands its very shortlived. Not any model showing anything sustained as things stand on model output  

Edited December 20, 2021 by swfc

[nick sussex]

Quite bizarre . The ECM ensembles for London seem on a different planet to the GEFS.

Not a single ECM ensemble for London gets below -5 upto day 10. Yet on the GEFS there’s quite a few .

One model and its ensembles are going to be eating a large piece of humble pie over the next days.

Edited December 20, 2021 by nick sussex

[sheikhy]

1 minute ago, nick sussex said:

Quite bizarre . The ECM ensembles for London seem on a different planet to the GEFS.

Not a single ECM ensemble for London gets below -5 upto day 10. Yet on the GEFS there’s quite a few .

One model and its ensembles are going to be eating a large piece of humble pie over the next days.

Im goin for the gfs to backdown!!!only because normallyy its the milder air that wins BUT ecm has moved towards the gfs so you never know!!!

[PiscesStar]

3 minutes ago, sheikhy said:

Im goin for the gfs to backdown!!!only because normallyy its the milder air that wins BUT ecm has moved towards the gfs so you never know!!!

I'm going for upgrades earlier on in the run as a hunch 

[JoeShmoe]

5 minutes ago, swfc said:

At the moment even if the Xmas cold lands its very shortlived. Not any model showing anything sustained as things stand on model output  

Kind of my view too, hundreds of posts on what is in effect a few hours of marginal snowfall . Many folks saw a lot more than that earlier this winter  

[tight isobar]

5 minutes ago, nick sussex said:

Quite bizarre . The ECM ensembles for London seem on a different planet to the GEFS.

Not a single ECM ensemble for London gets below -5 upto day 10. Yet on the GEFS there’s quite a few .

One model and its ensembles are going to be eating a large piece of humble pie over the next days.

My box of eggs are ready pal.. and I think I know which way I’m chucking em

[Cold Winter Night]

EC46 tonight:

Positive anomalies over the Arctic, first into Greenland (suggesting NAO-), then moving more to Scandinavia week 3-5 (suggesting Scandi High/BLO+ regime).
After that high latitude heights fading away, but that's a long way off (end of January).

[Staffmoorlands]

1 minute ago, JoeShmoe said:

Kind of my view too, hundreds of posts on what is in effect a few hours of marginal snowfall . Many folks saw a lot more than that earlier this winter  

Agree Joe. We had about 10cm of snow last December on the 28th. I can’t see us beating Christmas 2020 this year 

[Standfree 1903]

1 hour ago, Sceptical said:

It occurs.

11th Feb this year.

 

 

I can vouch for that,live over the hill from you,cracking winter,from Christmas Eve till the end of February,plenty snow and minus temps.Fingers crossed for a repeat this winter

[TanHillWeather]

Xmas day now within reach of the NMM model.

Here's what its showing for 1pm on the big day.

[Singularity]

Probably a bit of 'follow the leader' going on with EPS. After all, the ECM 00z starts nudging things north in the 3-4 day range.

The model feels 'off' for the setup but alas, that's not enough of a basis to overlook a model on.

Thinking of the broader, longer-term picture for a moment, the latest GFS prediction for how AAM unfolds in the next week is very telling:

Here, a model that has a known low bias with AAM is predicting that the measure will stay above zero in the low part of its cycle... during a La Niña event. This is highly abnormal and indicative of the 'unstable GSDM profile' that Tamara has been referring to lately.

Though the decline in AAM is small as a result, it will still be enough to promote some manner of height rise to our south. However, while a zonal flow to its north would be expected if AAM was falling into the negative values i.e. phases 1-2 of the GWO plot shown above, with AAM hitting a 'floor' at almost +0.5 sigma, the flow should prove to be more meridionally inclined. Which is to say, a good chance that the height rise to our south finds a way northward before long (once AAM climbs again, there won't be much in the way of zonal flow to 'scrub out'.

As usual, this is not a 'magic bullet' for a cold January. There might be a mild spell around NYD and then it will come down to the alignment of major blocking features. The AAM cycle should help, but as we're seeing currently, it's never as simple as 1,2,3...

Whatever the detail, repeated blocking patterns should keep the lower stratosphere highly perturbed. Whether there's any delivery of wave activity to the higher altitudes to try for a SSW in Jan remains to be seen but even if there isn't, a substantial disconnect seems likely to continue for quite some time.

[stodge]

Evening all

On we go along the edge for another 24 hours - I really did think after yesterday's step back we could see a big flip to milder charts this evening but that hasn't happened as yet.

My original take of a brief milder incursion into southern areas followed by a return to something colder on Boxing Day or this time next week still seems to be in the frame but so do many other options at this time.

As we've often said, micro variations on a regional level can make a huge difference in our small corner of the globe.

Looking further on and I now see GFS Control offering an alternative to the mild/very mild options previously on offer for the New Year. By having the mid-Atlantic LP stalling further west, it allows a general rise of pressure across NW Europe so we get another shot at a Scandinavian HP. The problem is if the Atlantic LP is too close, we get the classic west-based NAO set up with the Greenland HP no help and the Azores HP moving to Iberia and pulling up a very mild SW'ly flow.