Model output discussion - Closing in on Christmas

[nick sussex]

Great ending to the ECM run .

That would be the cold locked in for the festive period . The stakes just got higher ! 

The evolution is similar to this morning with the main features but the ECM tonight goes a step further at the end by disrupting the low to the west of Iceland and sending a shortwave se wards . 

 

[Mike Poole]

Will be very interesting to see where that op run sits within the ensembles, and what percentage are in the same cluster later.  Really good run, and a genuine surprise with the last frame, I was still thinking it would topple after day 9.

Edited December 15, 2020 by Mike Poole

[Climate Man]

Happy to take the ECM as an early Christmas pressie.  Probably gone in the morning though 

 Christmas day seasonal but beyond that the potential is huge. Fly in the ointment is the stormy Atlantic GFS.

[BlueHedgehog074]

8 minutes ago, Frosty Winter said:

Day 10 is also great, just hope we aren’t chasing rainbows again.

 

4 minutes ago, Tim Bland said:

Snow showers coming south xmas day!! 

Considering the way the last two Winters in particular have gone (aside from the Southern UK January 2019 snowfall), would quite happily take something like that for Christmas Or even something dry and/or frosty

Edited December 15, 2020 by DiagonalRedLine

[Ice Day]

I would have really loved to have seen days 11 and 12.  

Absolutely superb ending, BUT we have all been here before with day 10 ECM charts (especially those members that remember 'That ECM').  Cautious optimism at this point, nothing more!

[Duane S.]

ECM 00Z more than hinted...

Often, it isn’t about having a massive surge of WAA into Greenland (highly unlikely atm), combined with other factors nearby, it’s the direction of the advection. When you have vertical WAA to our west, it isn’t as flimsy a pattern as some may think.

Day 10 of the 12Zs perfectly reflects the potential after-effects of this, with the atmospheric conditions relatively conducive, as they currently are.

 

A long way to go before anything is decided yet.

 

[Matt H]

2 minutes ago, Ice Day said:

I would have really loved to have seen days 11 and 12.  

Absolutely superb ending, BUT we have all been here before with day 10 ECM charts (especially those members that remember 'That ECM').  Cautious optimism at this point, nothing more!

Yes, this ECM run was definitely needed this evening to keep the positive vibes going. Hope we actually get somewhere this time.

[joggs]

Just now, Ice Day said:

I would have really loved to have seen days 11 and 12.  

Absolutely superb ending, BUT we have all been here before with day 10 ECM charts (especially those members that remember 'That ECM').  Cautious optimism at this point, nothing more!

Yes. I reckon that low to the west would slide se and give somewhere a nice snowfall.

[LRD]

ECM saves the day. Superb from 192 to 240

The GFS ensembles weren't too bad either

 

[Allseasons-Si]

3 minutes ago, Ice Day said:

I would have really loved to have seen days 11 and 12.  

Absolutely superb ending, BUT we have all been here before with day 10 ECM charts (especially those members that remember 'That ECM').  Cautious optimism at this point, nothing more!

As is potential optimism

But you are right as it is still ten days away,lovely ECM though it has to be said and as @nick sussex says there would be a cold lock in from there with re-newed height's in the Atlantic.

[SLEETY]

All roads lead to cold on ECM at day TEN onwards,what a shock to see that ....

 

[Penicuikblizzard]

15 minutes ago, Frosty Winter said:

Day 10 is also great, just hope we aren’t chasing rainbows again.

Day 10 is always tasty  

unfortunately we never see these in the reliable 

[Day 10]

The ECM in simple terms for cold weather fans...

192

216

240

 

[Ali1977]

That low at the tip of Greenland rapidly weakens between day 9 and 10, and that’s the key as that stops the heights getting bowled over and let’s the second round of WAA enter the game behind it!! Lots to go wrong there, but nice to see.

Edited December 15, 2020 by Ali1977

[SLEETY]

I have lost count of day 10 ECM cold looking  charts that never verify and are completely different the next run.

Edited December 15, 2020 by SLEETY

[northwestsnow]

Nice EC ...

 

Let's get 120-168 straightened out first though...

[BLAST FROM THE PAST]

Well UKMO too is very good at t120 to t144 and smells very much of an ECM outcome.  GFS for me has gone off on one.

Remember that day 9/10 is FI, but this sort of set up was seen by GFS at t384 and by me at t3884  and the arrival has remained consistent.

I’m more pleased now and for me another day ticked off.

 

UKMO at t120

look at the artic HP spreading itself and the ridge building towards Greenland as the deep purples  get pushed apart, the LP to SW of Greenland goes nowhere indeed gets well held even after absorbing the sub low to its south...that will lead to a sharpening Atlantic ridge, a nice northerly and ECM land.  
 

see ya tomorrow 

 

BFTP

 

Edited December 15, 2020 by BLAST FROM THE PAST

[Guest]

20 years of model watching I've learnt never to write of a GFS outlier, especially when said outlier is a party pooper! ECM is clearly the best run of the bunch this evening but its still all FI. Cold spells need to be within 96hrs to start getting excited. 

When was the great beast failure? I suspect its longer ago than I'd like to believe. -12C uppers covering the UK @ T120hrs only for 5days later for a few places to end up with a couple of barely frosty nights 

[Daniel*]

EPS rolled out to T216 this is very interesting more substantial ridging centred near to Iceland compare to 00z and fitting more in line with operational?

[northwestsnow]

That chart looks fantastic Daniel..

Get in !!!

[TSNWK]

5 minutes ago, Daniel* said:

EPS rolled out to T216 this is very interesting more substantial ridging centred near to Iceland compare to 00z and fitting more in line with operational?

EPS and ECM mean that gets posted is there a difference?

[Daniel*]

Just now, TSNWK said:

EPS and ECM mean that gets posted is there a difference?

No same thing... lol 

[Yarmy]

Feels like the key to the 192-240 evolution is the clean separation of the energy over the CONUS in the 168-192 period. If the depression over the Midwest phases with the depression over Newfoundland then it would be curtains.

 

[SMU]

One post .....

The ECM scenario is modelled once / twice a winter & rarely comes off > maybe once in 15 or so times - This is because in the toppler scenario theres not normally enough initial attenuation in the jet to force low pressure up the western side of Greenland - 

Once they get past the western tip ( to the west ) there is a chance residual heights can stay in situ over Greenland.

Even if this is the case the 'norm' is a quickly subsiding jet across the Eastern seaboard & no upstream blocking over svalbard. So eventually the low just ploughs East not SE > rather like the GFS.

The ECM is modelling this due to a combination of

- Very sharp jet inclination at day 8/9

Remember my wedge forecast the other day... ECM almost in perfect place...

- The fact that the pacific jet stays amplified

- The low stays west of Greenland 

- Arctic High.

See here is the key area.

In Summary ECM portends to a very rare beast > strong enough cut off heights ( Not a greenland High ) to deflect the atlantic west of the UK.

Remember these very rarely varify > watch for that low getting east past the greenland tip & a more positive tilted jet which are signals it wont happen. ( a la GFS )

Perhaps a defining moment of Winter but dont really bank on it.... Its the difference between a chilly snap & cold spell...

Edited December 15, 2020 by Steve Murr

[Jeremy Shockey]

GEFS 12 z ensembles  850 hPa 

The GFS 12z Op was a little disappointing ( in comparison to the good ECM 12z and GEM ). However not a bad set of GEFS ensembles. 24th - 26th would be cold.