Model Output Discussion - Colder spell ending, what's to follow?

[Zak M]

The mean even gets the -4c isotherm into the south on Boxing Day..

[Ali1977]

Do t worry folks, the NASA and FIM

also have a day 10 ridge  #deadcert

[northwestsnow]

1 minute ago, Zak M said:

The mean even gets the -4c isotherm into the south on Boxing Day..

Precip becoming wintry

[Tim Bland]

06z Vs 12z mean @ 300hrs. Awesome set of ensembles coming up.

[nick sussex]

Snow over Christmas will be good on two fronts .

The vast majority of members here will be overjoyed and it will help the government as less people might mix especially if there’s enough to grind the transport network to a halt ! 

Of course NW members will be doing something very low risk . Outside and playing in the snow ! 

The last few days models wise have been trying for coldies but the GFS is doing its best to develop some interest .

The ECM has been less enthused so far , let’s hope that changes .

[Scott Ingham]

2 minutes ago, northwestsnow said:

Oh I do like the sound of that!

Looking at MJO hoping for a spark..

This is all MJO driven atm the atmosphere is almost at neutral levels of angular momentum and with it not responding aggressively to the NINA base state the MJO is this winters driver. Im just skeptical. What were seeing is classic phase 7 synoptics and most plots show us not hitting this for 10+ days. Then you have lag. Id have expected a scrussian ridge Christmas week. I can only think its modelling it to come out of the cod into this phase skipping phase 6

[Zak M]

Perturbation 25

   

[I remember Atlantic 252]

4 minutes ago, nick sussex said:

Snow over Christmas will be good on two fronts .

The vast majority of members here will be overjoyed and it will help the government as less people might mix especially if there’s enough to grind the transport network to a halt ! 

Of course NW members will be doing something very low risk . Outside and playing in the snow ! 

The last few days models wise have been trying for coldies but the GFS is doing its best to develop some interest .

The ECM has been less enthused so far , let’s hope that changes .

looks very dry! may be sunny for you, 9 degrees? unsure of SW France weather

[Blessed Weather]

Today's MJO updates disappointing. Forecasts now out to 27th Dec and backing off possible progress to Phase 7 or 8. Indeed, not even making Phase 6. Tomorrow's weekly 'expert analysis' update from NOAA/CPC is awaited with interest. The Nina base state has been a pain with destructive interference with the MJO progression so far this season.

GEFS:  ECM Ensemble:

[Eagle Eye]

Just fot fun lrt's look at a chart ages away and smile. 

 

[Decemberof2010]

So some interest for the Christmas period. Let’s hope the models firm up on this. P25 posted above would do nicely. 
Here’s how I’m expecting day 10 on the ECM to look
 

 

[feb1991blizzard]

57 minutes ago, Captain Shortwave said:

GEM suggesting the same scenario by day ten.

 

 

Its suggesting a much better scenario, that is a guaranteed notable cold spell with some significant falls of snow down Eastern and Western coastal areas if that went further.

[SqueakheartLW]

1 hour ago, SLEETY said:

looks like greenland high building,could be stonker at the end.

Does anyone see a repeat of Christmas period 2000 with the weather here?

[Allseasons-Si]

Afternoon everyone, been cooking Sunday lunch so i have not had much time to post,...have i missed much!!!

good model runs this afternoon and an impressive mean to boot well out into fl too

also quite a few gefs ens are going for a northerly too over the Xmas period

pert 11

i hope that they are not lying to us

[Sweatyman]

19 minutes ago, Ali1977 said:

Do t worry folks, the NASA and FIM

also have a day 10 ridge  #deadcert

Good ol'NASA not just a load of spacemen

[Scott Ingham]

9 minutes ago, Blessed Weather said:

Today's MJO updates disappointing. Forecasts now out to 27th Dec and backing off possible progress to Phase 7 or 8. Indeed, not even making Phase 6. Tomorrow's weekly 'expert analysis' update from NOAA/CPC is awaited with interest. The Nina base state has been a pain with destructive interference with the MJO progression so far this season.

GEFS:  ECM Ensemble:

Id keep a keen eye on this Malcolm as one of the features of this winter is for the convective waves to be heavily under estimated. Granted these are a backward step from the previous update.

[Tim Bland]

By Xmas Day evening GEFS are down to -4.5c uppers as an average in the south! Here is the full list

[northwestsnow]

15 minutes ago, Blessed Weather said:

Today's MJO updates disappointing. Forecasts now out to 27th Dec and backing off possible progress to Phase 7 or 8. Indeed, not even making Phase 6. Tomorrow's weekly 'expert analysis' update from NOAA/CPC is awaited with interest. The Nina base state has been a pain with destructive interference with the MJO progression so far this season.

GEFS:  ECM Ensemble:

Oww thats not good news at all, in view of us needing as much amplification in the Atlantic as possible.

[Djdazzle]

Some interest starting to reappear. But it’s all still in the far reaches of Fi - don’t get sucked in yet folks!

[Daniel*]

I can’t say I’m particularly surprised to see colder outputs EPS has been showing it turning colder just in time for Xmas for a few days now. ECM op just about coming into range now....

[LRD]

Last winter the IOD demolished cold chances. This winter it could be the MJO or lack of

Time to call this lad:

And if the ensembles are misreading MJO signals it could mean that the best set of ensembles so far come to nowt:

Which'd be a bloody shame as from 23rd/24th those 850s are dropping quickly

Edited December 13, 2020 by LRD

[Mr.B]

5 minutes ago, LRD said:

Last winter the IOD demolished cold chances. This winter it could be the MJO or lack of

Time to call this lad:

And if the ensembles are misreading MJO signals it could mean that the best set of ensembles so far come to nowt:

Which'd be a bloody shame as from 23rd/24th those 850s are dropping quickly

So does the MJO drive the ensembles or do the ensembles drive the MJO or do they independently read the background signals?
 

Sorry LRD not directed at you personally just interested. 

[Tim Bland]

GFS Vs ECM 144hrs, fairly similar so far

[LRD]

3 minutes ago, Stevie B said:

So does the MJO drive the ensembles or do the ensembles drive the MJO or do they independently read the background signals?
 

Sorry LRD not directed at you personally just interested. 

The models (in this case individual GFS ensemble members) will read all the signals punched into it before every run and if the reason they're driving a mid-Atlantic ridge is because they think the MJO will do something then it will react to that. If it is misreading the MJO then most of those runs will be wrong. Let's hope they're not wrong but Blessed Weather's post is not good news

The ensemble members and other models might be picking up on something that's not MJO-related, though, so who knows. Scott Ingham is better-qualified than me to explain though

Edited December 13, 2020 by LRD

[Mike Poole]

1 minute ago, Tim Bland said:

GFS Vs ECM 144hrs, fairly similar so far

ECM a tad more amplified, I’d say, let’s see how this one pans out.