Model output discussion - The run up to Christmas

[Uncertainty]

Good evening all.
 

That’s the GEPS at 300hrs. WAT. Those euro heights are in a great spot. 

Loving the upgrade on the EPS tonight...

 

On the latest GEFS we have a mean northerly at day 9:

looks neither too Far East nor west to me. Great angle. Here in NE Cumbria the Solway negates the snowy potency of most NWerlies but a true Northerly with embedded troughs and low thicknesses might be a different matter...

Weird to see ECM following GFS but it isn’t the first time over the last year or so...

The extraordinary persistence of the GFS In predicting this pattern is a real coup for the FV3. I can’t remember a non zonal pattern being this consistently modelled from day 13-7.

Lets hope it’s right about the SSW in the strat too!

However, The 12z, whilst spectacular for reversal speed, left a daughter vortex in the Atlantic. These have been sour for us in the past, especially two winters ago.

I would rather have a 1984/1985 situation where the secondary warming is in the Atlantic, we might see this on this run...

 
 

Looks ideal!

The 46 tomorrow will be vital, hopefully a lot more members back the GFS and go full reversal. I still think the GFS is jumping the gun a tad but it looks genuinely likely we’ll see a major midwinter SSW come the middle of Jan. 
 

Ive mentioned frequently that may faith in the SSW/subsequent downwelling effects etc have been dampened by strong positive NAO touted by the seasonal models. This time they have seen most of the developments we have over the last month. Hopefully they flip big time and we can begin to contemplate the first cold winter for 8 years.
 

PS I noted today that the meto 30 Dayer backed off the return of Atlantic mobility completely. No reason to disagree with that based on this evenings output

 

Edited December 20, 2020 by Uncertainy

[Stu_London]

I think there will be more scatter on the long ensembles than recently. Days 8-16 were remarkably tight (and cold) over the couple of runs

Edited December 20, 2020 by Stu_London
grammar, spelling

[Matt H]

16 minutes ago, Zak M said:

I love Sheikhy's optimistic posts, but I've got a feeling he is going to do something weird with all the '' emojis at the end of his posts whenever a model is showing something good

We might have to roll out the zonal charts from 2015 again to tame his excitement.

[Cheshire Freeze]

3 minutes ago, Stu_London said:

I think there will be more scatter on the long ensembles than recently. Days 8-16 were remarkably tight (and cold) over the couple of runs

850's mean is marginally colder at D10

[Allseasons-Si]

The control  run is identical to the gfs with the renewed amplification in to Newfoundland,...W.T.F

[Jason M]

GEFS are really good at day days 8 & 10. Finally tonight we are seeing some charts bring better 850s into the mix. Some really cold runs amongst this set of ensembles. Very positive end to the day but as know the what the pub run giveth the morning runs often taketh away . 

Really pleasing to see some cold breach the 192 hours line. Plenty could go wrong but we are off the starting grid in my view.

[Catacol]

40 minutes ago, lorenzo said:

There are wave breaks - then there are wave breaks.

Stunning synoptics, it's as good as it gets for poetry in this image.

The vortex clinging to it's climatological home with that furious filament, the inevitability of the Greenland break

combined with the Ural Torque and the Aleutian Low.

Vortex is toast.

 

Yeah Lorenzo - something special in the wings. Whether we get a cut off Greenland ridge or not, the global pattern is setting up for a proper split SSW. Given the likely pattern at the New Year I’m tempted to suggest we will be unlucky if we don’t see some icy fallout here.....though trop impacts of a SSW are a lottery really. Only time will tell but these are the best midwinter synoptic preconditions since 2010.

[Stu_London]

1 minute ago, CreweCold said:

850's mean is marginally colder at D10

That can't be a bad thing. 

A seasonal if largely dry Christmas Day is welcome after the last few. 

Some snowy weather is starting to look more likely (for some, at least) thereafter.

My biggest concern on the 18z would be how quickly the heights over Greenland collapse compared to previous runs - we still end up with a good run for cold - but there might be some other perturbations that aren't as pretty.

[Lampostwatcher]

Gfs 18z 

❄❄❄

[Scott Ingham]

25 minutes ago, CreweCold said:

I think the 9th was touted by the professionals...so it could be the GFS is a week early. We'll see.

Yeah Amy Butler suggested the 7th.

I had 15th down on strat thread about 2 weeks ago. I still think Amy Butler will be spot on.

If the GFS comes off its the largest event this early ive ever seen! But that has to be watered down surely!

[Scott Ingham]

26 minutes ago, Snowman. said:

 C L E A N

Split in a beautiful place

[Scott Ingham]

27 minutes ago, weirpig said:

Brilliant short ensembles   snow row going up   and the period after Christmas as the mean around -5   

Look at the snow rows 27th and 28th! Tasty!

[Jason Lancett]

Until @Steve Murr.. comment's.. I'm not onboard

[Scott Ingham]

28 minutes ago, feb1991blizzard said:

Perfect split right up top!.

 

That is so beautiful. Perfect!

[Scott Ingham]

28 minutes ago, CreweCold said:

I think if you gave the likes of @chionomaniacand @lorenzo carte blanche to pick a place of split, that would pretty much be it.

Its literally perfect that mate

[Scott Ingham]

27 minutes ago, Snowman. said:

It's perfect. I just can't stop thinking about it, would be a fantastic cold spell if it was modelled 1 to 1 in the trop.

In other news, P2 has the low cleared sufficiently east and much less intense resulting in the following.

 

This is the potential landing zone! Bookmark it!

[Catacol]

29 minutes ago, Met4Cast said:

I've gone for the 7th in Simon Lees competition on Twitter. Some two weeks earlier than the 2018 SSW so it really couldn't be more perfectly timed. Whether it downwells & has a favourable impact for the UK however is the next step to worry about.. but we're certainly miles away from the mild & unsettled second half to winter many (myself included) were expecting at the beginning of this winter.

2018 was a February event. Downwelling impacts were visible within 2 weeks. The trop was less favourably setup back in 2018 (my opinion only...) so I’m looking at something here that is developing in an extremely positive tropospheric context. As @CreweCold has said - we have a context here that suggests we could go cold from trop or strat (or both) origins and with a pinch of fortune it could dig in for more than just a few days. Exciting stuff.

[Allseasons-Si]

All roads lead to Rome...UK IMO..

...on the control run

great output today/tonight, and great discussions, love it.

 

[Scott Ingham]

26 minutes ago, Met4Cast said:

That is without doubt, one of the most beautiful charts I have seen in terms of stratospheric warming & splitting. I don't think it'd be possible to draw a more perfect split.

Angle of attack wouldnt be far from a 1987 scenario. I can see the Russian lobe dropping into Scandinavia into western Europe

[Updated_Weather]

5 minutes ago, Jason Lancett said:

Until @Steve Murr.. comment's.. I'm not onboard

He has a life outside this forum you know

[MATTWOLVES 3]

Excitement a plenty on those 18z ens...All eyes firmly fixed on the 0z runs now,hopefully further upgrades.

[seajamiet]

Been following the models for around 4-5 years but rarely post - everything I've seen and been reading is mostly positive. Don't remember often seeing these outputs in December if at all, pretty sure in the last few winters we've been staring at a bit of a zonal period in the run up to Christmas. Nice to see SSW possibilities showing too which'll keep the interest going no doubt. Looking forward to the next few weeks

[Scott Ingham]

25 minutes ago, Mike Poole said:

GFS pub run, T384, down here and up there:

You can’t disconnect them though.  I still want to see the SSW on the ECM Berlin charts to have a good idea on the likely way forward beyond the next couple of weeks.  

Finally the JMA T264:

I did post this earlier, but in the coronavirus thread!  Who knows what they made of it there!  Theme: rinse and repeat on amplification.  

Another possible Griceland high there

[Scott Ingham]

25 minutes ago, Uncertainy said:

Good evening all.
 

That’s the GEPS at 300hrs. WAT. Those euro heights are in a great spot. 

Loving the upgrade on the EPS tonight...

 

On the latest GEFS we have a mean northerly at day 9:

looks neither too Far East nor west to me. Great angle. Here in NE Cumbria the Solway negates the snowy potency of most NWerlies but a true Northerly with embedded troughs and low thicknesses might be a different matter...

Weird to see ECM following GFS but it isn’t the first time over the last year or so...

The extraordinary persistence of the GFS In predicting this pattern is a real coup for the FV3. I can’t remember a non zonal pattern being this consistently modelled from day 13-7.

Lets hope it’s right about the SSW in the strat too!

However, The 12z, whilst spectacular for reversal speed, left a daughter vortex in the Atlantic. These have been sour for us in the past, especially two winters ago.

I would rather have a 1984/1985 situation where the secondary warming is in the Atlantic, we might see this on this run...

 
 

Looks ideal!

The 46 tomorrow will be vital, hopefully a lot more members back the GFS and go full reversal. I still think the GFS is jumping the gun a tad but it looks genuinely likely we’ll see a major midwinter SSW come the middle of Jan. 
 

Ive mentioned frequently that may faith in the SSW/subsequent downwelling effects etc have been dampened by strong positive NAO touted by the seasonal models. This time they have seen most of the developments we have over the last month. Hopefully they flip big time and we can begin to contemplate the first cold winter for 8 years.
 

PS I noted today that the meto 30 Dayer backed off the return of Atlantic mobility completely. No reason to disagree with that based on this evenings output

 

We called the GFS mate. Its come together. How beautiful is that warming?!

[Allseasons-Si]

Mean at 300....

the upgrades keep on coming,i mean,..take a look at that,notice the finger of colder uppers to the NE^

 

 

 

Edited December 21, 2020 by Allseasons-si