Model Output Discussion - Deeper into Autumn

[Downburst]

The ecm is cool at the end of the run, but not cold. Yes it’s full of potential, but to set expectations it won’t be out of the ordinary at all for early December. The bast thing is to shut off Atlantic. 
Temps and 10 meter wind direction 

percipitation type

snow depth end of run

there’s actually a negative deviation in snow to the east at the end of the run. More signs of the times perhaps

[Cold Winter Night]

4 minutes ago, bluearmy said:

Extended eps mean is flatter to our west 

The clusters show a 50/50 split between either flat or very amplified towards Greenland.

The mobile Atlantic cluster was not really there this morning, but still, it seems to hint at an amplification attempt in that last frame IMO.

[phil nw.]

Not too excited by the ext(15 day) gefs/gps.Yes we develop a Scandi.trough but the High to the west not inclined to visit as far north as Greenland.

Time yet of course for the pattern to evolve.

[sheikhy]

Hmmm few back to earth posts this evening lol!!!!anyone seen the ec46 yet?!!please tell me its blocked

[northwestsnow]

1 minute ago, sheikhy said:

Hmmm few back to earth posts this evening lol!!!!anyone seen the ec46 yet?!!please tell me its blocked

It's OK ..

No signal for height rises around Greenland though..

[LRD]

9 minutes ago, sheikhy said:

Hmmm few back to earth posts this evening lol!!!!anyone seen the ec46 yet?!!please tell me its blocked

A bit inconclusive but it doesn't look as good as it did a few runs back. Got to say I don't rate the EC46 but good that it's trying to push long range forecasting as a science

[bluearmy]

Week three control cluster (largest)  on the 46 is ridge to our west and trough to our east 

given that this is a feasible route of travel out of the current exit ens, it’s notable. 

[Singularity]

A combination of an MJO-driven positive East Asian mountain torque event & the polar vortex drifting away from Canada/Greenland for a while means a legit chance for high pressure to build up through the UK or hereabouts and attempt to establish a high latitude block, albeit not of the full-on Arctic variety (AO not looking to drop negative enough).

However, the modelling seems very uncertain on the timing of this and hence what it has to interact with to our east.

Earlier timing makes it likely to have a Scandi-west Russia high to link with, giving us a probable easterly but who knows how cold (fine detail important there).

Later timing makes it more likely that the high to our NE/E has moved on with a trough in its place. Then it becomes a case of whether the high can reach as far as Iceland/Greenland as to how cold and inclined to snow the UK weather becomes.

These two pathways are tied to MJO forcing, phase 7 Scandi high promotion followed by phase 8 Atlantic high with chance - but no guarantee - of a negative NAO spell.

Should the earlier advance north of high pressure occur, it’s certainly plausible that we see one scenario then the other: High links to Scandi-Russia high then the merged feature retrogrades toward Iceland/Greenland. This is the rarest outcome, mind.

[Rain All Night]

It must have been a while since one of these CPC plots came out not showing any negative height anomaly in the North Atlantic at all.

[Cambrian]

Well, you can’t win ‘em all, but sometimes it’s good to still be in with a shout, even if you have to wait well into the second half of the run for things to come good. The 12z GEFS mean shows the extent of the turnabout and the change in momentum is striking. The ECM looks to be playing the longer game for now, but it’s good to have the GFS on side. 

  

Not only is the Atlantic trough taken out of play altogether by day 11 on the mean anomaly chart, the mean itself is toying with an easterly counter, accompanying a formation of low heights cutting straight through the midfield of Europe. Plenty of chances for a good shot of cold by then in the T850 ensembles, from which we can draw much comfort, because as we know, in this game, it often only needs one or two chances like that to hit the target to make it truly memorable.

[sheikhy]

Gfs para looking good so far at 162 hours!op not looking too bad either

[sheikhy]

Meteociel crashed lol!!!very good para!!not sure bout the op!

[blizzard81]

2 minutes ago, sheikhy said:

Meteociel crashed lol!!!very good para!!not sure bout the op!

Yep it's gone awol. 

[blizzard81]

Had to revert to wetter for the first time in many years lol. Para looking good. T180. Op is much flatter so won't bother showing. 

[sheikhy]

2 minutes ago, blizzard81 said:

Had to revert to wetter for the first time in many years lol. Para looking good. T180. Op is much flatter so won't bother showing. 

Thats exactly what i have done in last 20 mins!!not a fan of wetterzentrale i must say!!gimme meteociel all day long!!

[blizzard81]

Para at day 10.

Just now, sheikhy said:

Thats exactly what i have done in last 20 mins!!not a fan of wetterzentrale i must say!!gimme meteociel all day long!!

I know what you mean lol. Meteo is so much easier on the eye. 

[January Snowstorm]

The para looks awesome above!!

[Ali1977]

11 minutes ago, January Snowstorm said:

The para looks awesome above!!

The Op seems to have thrown any blocking in the bin - strange but I imagine it’s a wobble!! 
Day 11 below

Edited November 21, 2022 by Ali1977

[Eagle Eye]

*Some of this is just how I've read parts of the thread and I may have understood wrong, I do that often.

With the Nino state atmosphere and disconnect from the oceanic Nina and mixing that in with MJO phases 6 and 7 as lag correlations and in your head you will get a fairly good example of what the models are showing now. With amplifying  jet undulations stronger due to the less westerly zonal wind, warm air advection(WAA) occurs and so it is pushed up. This is a fairly good broad early setup for a decent -NAO in general. So there's no real reason to not believe the models at the moment but it's still too far away and it's only a general idea we've got at the moment. Phases 6 and 7 don't always bring a -NAO, they just have higher potential compared to the rest of the MJO phases.

Almost all of this will have a lot to do with the strength of the westerly jet, the weaker the westerly jet in the Troposphere, the more WAA there is and the better the chance of a -NAO.

The evidence for a -NAO is fairly good, Nino AAM, MJO in the better phases, slightly weaker westerly winds in the troposphere than last time but everything may not coincide. We've seen this before but that doesn't mean we can't ramp it. Every time is a different time, the setup is convincing enough and the teleconnections are showing good signs so there's a lot to be hopeful for. Just don't get too worked up if it doesn't come off, we've got a long time left of potential widespread cold opportunities to go so it wouldn't be that bad.

Late into November and early December is probably going to be our best chance. Weaker Surface to Tropospheric zonal wind, MJO lag correlated with MJO phase 6/7 and the consistent Nino AAM.

Looking beyond this and the EHF anomalies forecasted are looking a lot better, with strengthening vertical propagation in the mid term on both of the main models. Still too far away though.

Think it's a case of too far away for the upcoming chance and too far away for any recognisable SSW chance so it's the waiting game for now.

[swfc]

18z looks dry and cool tonight. Settled at least

[Allseasons-Si]

5 hours ago, bluearmy said:

Extended ens geps and gefs are dropping euro heights and slp ……

geps is finished - gefs looks like it’s headed same way 

I have the charts mate and they are looking good,the EPS less keen on lowering heights into Europe but still not bad

dam meteociel,...i have been using that for years

the 8-14 day cpc has a surface noreaster(red contours) with upper westerlies(green lines) so could be quite chilly

the 18z op and parra miles appart but both still go with amplification but at different locations

steady as she goes,...at least there is nothing zonal about the models,...ATM.

Edit:just to add that there is more east to northeast winds starting to show on the ECM ens for De-built.

will have to watch these to see if the %age increases over the coming days.

 

Edited November 21, 2022 by Allseasons-si
typo/added info

[Allseasons-Si]

Meteociel is back up

[Cheshire Freeze]

oi oi, the ICON is on board

[Cheshire Freeze]

D7 GFS is excellent

[Cheshire Freeze]

Calm, cold and frosty under a holding pattern of sorts...there is some insane cold around the NH for so early in the season