Model output discussion - Closing in on Christmas

[Tim Bland]

As others have said ; great set of ensembles. Closing in on a very cold end to the year with the mean uppers in the south now approaching the magic -5. 

[Daniel*]

I would love to see a UKMO that goes out to day 16 like GFS then you might seriously question how good it is, it only shows up to a semi reliable timeframe so we never truly see it demonstrate true skill like a day 10 forecast verifying. The GFS / GEFS forecast the cold snap over Xmas 10 days out. 
 

 

Edited December 19, 2020 by Daniel*

[Mucka]

UKMO 17th/19th 12z runs comparison for Dec 23rd

 

 

GFS 17th/19th 12z runs comparison Dec 23rd

 

Looking at he above I would say GFS has been more accurate with predicting the likely upstream amplification and UKMO has been playing catch up.

GFS is pretty good in the Atlantic sector out to day 7 or so which is why I took notice when it was the first run to drop the more amplified ridge for Xmas period and instead pushed what has become the trigger low through. (If it happens, Got to member it is all just data and projection for now)

[feb1991blizzard]

12 minutes ago, Djdazzle said:

You can argue about which model is best until the cows come home!

Any prolonged cold is still an outside bet, even with the improvements in the GEFS.

In the next few weeks yes, but if the SSW can materialise, that could be a game changer.

[Matt H]

Uppers looking fairly decent for most on Christmas Eve on the ECM. Hopefully some will be able to enjoy some festive snow.

[Kasim Awan]

16 minutes ago, Djdazzle said:

You can argue about which model is best until the cows come home!

Any prolonged cold is still an outside bet, even with the improvements in the GEFS.

Didn't know we were expecting these models to predict tornadoes

Nontheless, ECM looks chilly fot Xmas eve. Already a good deal of cold air to the north so even the modest nortberly produces uppers of -6/-7, though this run has heigher heights so lower shower risk 

[That ECM]

T120 all 3. 

[Mike Poole]

ECM in the middle of  GFS and UKMO at T120:

[swfc]

9 hours ago, northwestsnow said:

We need GEFS to be right.

EC will get flatter and flatter unless it pulls some Atlantic amplification out of the bag , sharpish.

NW you still sticking with the GEFS? 

[Mucka]

That ridge across the UK is not welcome for me but we will let it play out and see what develops.

Need those heights sucked quickly W and the trough to drop S/SE

Edited December 19, 2020 by Mucka

[Captain Shortwave]

    

Possibly some showers still running into the south east with a flow east of north. Looks pretty cold and sunny for most. 

[Frosty.]

I’m sure this post will get lost in the ECM frenzy like tears in rain.classic Blade Runner quote there!...anyway, I’m quite happy with the GEFS 12z going forward, much better than recent pathetic years at this stage!

 

Edited December 19, 2020 by Jon Snow

[Jeremy Shockey]

ECM 12 z 850 s

Cold uppers hanging on for much of England for Christmas Day ( as well as Christmas Eve p.m.) .

 

[northwestsnow]

7 minutes ago, swfc said:

NW you still sticking with the GEFS? 

Nope.

 

[Kasim Awan]

One is 15th Dec 2010 and one is ECM 144H. You decide.

Just saying the upstream component has *potential*. No guarantee that this will be realised. 

[Mucka]

I guess on the plus side we would likely get a more direct N flow so long as the trough drops and the amplification is there behind.

Edited December 19, 2020 by Mucka

[Matt H]

Looks better than the 00z to me at t168...

[Mike Poole]

ECM T168

Compare GFS same time:

In view of later developments on GFS this run could be better in the long run.

Edited December 19, 2020 by Mike Poole

[northwestsnow]

Looks better at 168....

More amplified ...

[Weathizard]

PV is coming to town? My only concern so far with this run is the potential for it to be a bit too west based

[Drifter]

I worry if the high doesn’t retrogress, the low may end up going south and splitting it, leaving us with a euro high. 

[Scott Ingham]

7 minutes ago, Mucka said:

I guess on the plus side we would likely get a more direct N flow so long as the trough drops and the amplification is there behind.

There is the christmas day high i had mused about i just wish it was a few thousand miles west and i was wrong! But a Greenland High was next on the agenda so i hope we follow the meomentum script!

[That ECM]

[Mike Poole]

ECM T192 much better angle of attack but cold air will be a couple of days behind:

Edited December 19, 2020 by Mike Poole
Sorry, posted wrong chart

[Scott Ingham]

3 minutes ago, That ECM said:

Ecm edging to the GFS. Tomorrors runs if we can get the ECM finally on board it will be an enjoyable days model watching!