Model Output Discussion - Into Winter

[LRD]

Day 10 and similarities between the GFS op and the ECM op are obvious

GFS

ECM

Could be both agreeing on an incorrect idea of course but it's probably worth noting

[Derecho]

3 minutes ago, Cheshire Freeze said:

I feel we’re on the cusp of something potentially extreme into December. That cold to the E has been building steadily for a while now.

It has been colder then average in Scandi since mid-October!

[TSNWK]

Does exm control go out beyond 240? I think it might do... be Interesting to see if it does

[Empire Of Snow]

15 minutes ago, January Snowstorm said:

A couple of things worth commenting on at this stage:

1 - Almost all of the Long range forecasts are already bust. Early December is panning out very different to what was forecast. Are we in uncharted territory with GW etc and it's likely affects.

2 - Depth of cold over Europe. Have we ever seen that depth of cold so early in the season. I certainly don't recall it in the Internet age. With such warming going on across the world how in earth is it happening?!

We've had a couple of near misses and very odd starts to Winter over the last 3 years. Massive potential that faded. Is it a case that we were unlucky and that luck is now coming good. Below ECM's musings at 240hrs. Bitter bitter cold out East!

I really can't see anything unseasonal. There have been many years after 2000 with this deep cold in the NE. The majority of times an Azores ridge brings this cold towards SE Europe. Also back in the late 80s and early 90s mid December was the most snowy period for SE Europe at low levels. 

We need a proper blocking to get anything from NE and this is not in the cards right now unfortunately. 

[Cheshire Freeze]

Just now, Derecho said:

It has been colder then average in Scandi since mid-October!

As long as that remains the case, we’re pretty much one bout of amplification away from something very wintry…given the CW you’d have to say the dice are loaded in our favour. 

[Mark wheeler]

4 minutes ago, TSNWK said:

Does exm control go out beyond 240? I think it might do... be Interesting to see if it does

It does indeed .

here

Meteociel - Cartes Ensemble CEP/ECMWF ENS

WWW.METEOCIEL.FR

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meteociel propose des rubriques météo temps réel, forums, modeles...

Tantalisingly close 

Edited November 30, 2023 by Mark wheeler

[Allseasons-Si]

3 minutes ago, TSNWK said:

Does exm control go out beyond 240? I think it might do... be Interesting to see if it does

Yes,...it goes out to 360...

Meteociel - Cartes Ensemble CEP/ECMWF ENS

WWW.METEOCIEL.FR

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meteociel propose des rubriques météo temps réel, forums, modeles...

 

[Optimus Prime]

10 minutes ago, Derecho said:

December 2002 saw intense area of cold over eastern Europe, Russia and Scandi throughout that December. Closest analogue I can think of as that was also an El Nino.

That also attempted to bring the cold west early on that month. Hopefully we go one better this time.

This should offer some comfort for coldies, it still shows the possibility of notable cold in a warming world, something which I've been alluding to for a numbr of years now.

Switch off the Atlantic flow and you bottle up all that heat in the tropics. 

Yeah, I had a look through on climatereanlzser going back to 1979 and it was a struggle to find cold this intense so early on in the season. It was also not possible to find warmth anywhere near the sort highlighted in red on the map there. 

[Severe Siberian icy blast]

25 minutes ago, bluearmy said:

The northern annular mode is another term for the arctic oscillation 

the chart Dennis posted is looking at it through the whole atmosphere from the top of the strat to the surface 

Down in the trop you can see that we are forecast to have a neg AO and even high up at the top of the strat there is a short lived reversal near to the pole 

this is a gfs based forecast from the op run so whilst it’s likely to be fairly decent high up, down in the trop it could easily be wrong as the run heads through week 2 

A great explanation there abit lazy on my part not do my research on this occasion but i have fifa on pause in a champions league semi final  

I figured most of it out but what better place to ask a question in the best weather forum in the world ?!

Thanks guys for all you're replies

[wightwootton]

The Scandia high stopping Storm Agnes pummelling through the UK in September said to me then that we should watch the high pressure over Scandinavia this coming Winter!!!

In fact I think the second storm Babet did almost the same !!!

[TSNWK]

2 minutes ago, Allseasons-Si said:

Yes,...it goes out to 360...

Meteociel - Cartes Ensemble CEP/ECMWF ENS

WWW.METEOCIEL.FR

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meteociel propose des rubriques météo temps réel, forums, modeles...

 

Thank you.. so near to something really special as it trundles out to continue where ecm op ended at day  

 

[Lukesluckybunch]

After seeing the ECM it gives us all something too look forward too,on the 18z if not tomorrow morning..hopefully the gfs will start sniffing it out!

[LightningLover]

@Bricriu To answer your earlier question re. January 1987, the upper air over far Eastern Kent was as low as -19c!

Edited November 30, 2023 by LightningLover

[LRD]

3 minutes ago, Lukesluckybunch said:

After seeing the ECM it gives us all something too look forward too,on the 18z if not tomorrow morning..hopefully the gfs will start sniffing it out!

The GFS is already 'sniffing it out'

Not far off the ECM at all

[Dennis]

a special event soon for the strato first week december23

the normal westerlies turns to easterlies 

 

[Met4Cast]

1 hour ago, icykev said:

My money  would be on No 2 @Mike Poole, been looking like scandi high for a while now imo. We'll see Got to love the drama of the model output yet again. Interesting pub run too coming up. Maybe the Atlantic influence and return of westerlies@Met4Cast alluded to again will be wrong again. I believe the causes/drivers of our weather are not fullly understood yet, especially how they interact with one another and tbh I'm not sure they ever will be, its too complex imo.

Stella's baps and maybe snow shoes on @legritter

What I would do for a really cold snowy white Christmas  

Here's to hoping  

BTW @Met4Castno dig, you're one of the best, very knowledgeable and thank you for sharing your skills on this great platform

If you read my posts I’ve actually been suggesting option 1 in the last couple of days I.e a return to stronger westerly momentum across the Atlantic but with the potential for a south-shifted jet stream. 

I don’t buy a return to full classic zonal weather. 

9 hours ago, Met4Cast said:

We are seeing some changes, AAM tendency is spiking (increasing westerly momentum) which is the signal for an Atlantic return next week as the increased momentum moves downstream. 

As Tamara alluded to in a post yesterday though, where this returning momentum ends up remains very uncertain, it still remains possible that we see a south shifted jet stream & indeed modelling does seem to be converging on this, despite the trend to "less cold" conditions we're not really seeing anything within the ensembles to suggest blow torch south-westerlies are on the way. 

With the jet likely aligned NW>SE we're unlikely to see the cold blown away from Scandinavia, a few southerly tracking lows could in theory tap into the colder air to the NE at times.. worth noting the potential for some very deep lows moving into the UK December week 2 as well given the sharp thermal boundary. 

If I was on a hill in the north i'd be raising an eyebrow for sure!

Edited November 30, 2023 by Met4Cast

[TSNWK]

Right O we are only as good as the last run… icon 18z rolling…. 
 

bloomin relentless

[LRD]

10 minutes ago, Mark wheeler said:

It does indeed .

here

Meteociel - Cartes Ensemble CEP/ECMWF ENS

WWW.METEOCIEL.FR

---

meteociel propose des rubriques météo temps réel, forums, modeles...

Tantalisingly close 

New Year's Eve 1978 KLAXON

[danm]

37 minutes ago, January Snowstorm said:

Bitter bitter cold out East!

Crikey! I’m in Lapland from 13th-16th December. Could be absolutely frigid. 

As long as the pool of intense cold remains, we are potentially not far off tapping into something special. Just need the synoptic pattern to set up favourably. 

[Severe Siberian icy blast]

What a beautiful start to winter this is. 

Its come through the back door this one we all know it. Hindsight is a wonderful thing to look back at and learn and develop but what we have now is not the normal set up and for ones that's new if you wanto learn honestly study through archive's and you will soon figure out all of the famous winters of the past 

47/62/77(?)83/90/91 etc to more modern days of 09/10/13/18 

95% of them is from charts like we're seeing now. 

No assurances at all, the weather makes fools out of us all every day but time will tell if we can find the key to holy grail or its to become an incredibly frustrating near miss again!

 

 

 

Edited November 30, 2023 by Severe Siberian icy blast

[Lukesluckybunch]

ICON makes something of that feature Saturday night into Sunday..couple cms for those in the midlands

[Rain All Night]

Things aren't looking so great beyond day 6 down in my neck of the woods according to the ECM 12z ensemble, though you can see the footprint of ensemble members like the one shown below on the meteogram spreads in week 2...

Edited November 30, 2023 by RainAllNight

[BLAST FROM THE PAST]

 

beautiful…..that’s what we want to see going forward.  Relaxation of minor sorts

 

BFTP

[Mike Poole]

Tomorrow will be the first day of winter.  Here are the current temperature anomalies across the northern hemisphere, this is our starting point this year:

The state of play right now, as I see it, is as follows:

• The most immediate factor (other than will it snow on Sunday) is whether the current cold spell will come to an abrupt end with a resurgence of the Atlantic in a week’s time.  
• On here, many have made convincing arguments based on the model output that mild will quickly prevail.  Some of us (including me) have looked for evidence that the cold will prevail, if not in totality, to sufficient extent that it can readily be reloaded when background signals become more favourable again around mid-December.  
• The models clearly struggle in terms of how easy the cold pool to our east and northeast will be to dislodge, and are taking this down to the wire.  But today sees that swing of the pendulum away from an Atlantic zonal reset, towards one of two other options, trough disruption and a sliding train of lows on a southerly tracking jet, or a stalling, deeper low pumping up a Scandi high.
• Both of these options carry some risk, the first that the jet does not track far enough south, the second that the pattern happens too far east. 
• But they could be the start of an epic winter.  We just don’t know yet.  This is where the current temperature anomalies come in.  They are extraordinary - look at the heat over Greenland, the cold pool to our east and northeast, warmth in the USA.  
• If the Atlantic is indeed to be held at bay with what is actually quite a meagre block, it is because there really is no polar vortex driving it.  That is banished to the other side of the hemisphere.
• Enter the stratosphere, where for the first time in 30 years we have an early winter Canadian warming, ensuring a weak strat vortex for the foreseeable, and possibility of a SSW down the line.
• The MJO is predicted to return to Phase 7 about mid month, and AAM is forecast to rise on that timescale, this will promote blocking once more.  I am much more comfortable if this happens with an imprint of the current pattern (particularly the cold pool) remaining, it will reload the blocking in favour of UK cold, giving our second major bite at the cherry.  [If we have to endure a period of strongly Atlantic dominated weather (and let’s not forget the GFS 6z FI) in the meantime, I’m less confident.  The MJO has form for failing to deliver in that scenario, the Atlantic is difficult to stop in full flow.]
• Then there is the possibility of a SSW in January, outcome of course uncertain, but it would likely (in combination with El Niño) produce a cold end to or extension of winter.  This is our third bite at the cherry.
• But most of all, in my mind, is the nature of the weather patterns this year - extreme weather all around the world caused by stuck patterns.  We could be seeing the start of one now.

Of course, it could all vanish on the 0z runs.   But could it, really?  We will see…

All the best

Mike

[alexisj9]

4 hours ago, Jackski4 said:

Keeps being pushed back.. thought I was the only one who noticed

Nope I've been quietly watching, obviously no one knows when the push backs re cold will stop, but I'm personally not taking anything past Sunday as nailed, and even Sunday will still have adjustments. It's just the nature of cold synoptics, they always have a high level of uncertainty. I do expect the Atlantic to have some influence, mostly in the south, but other than that, I'm not calling this cold spell over. The snow line will rise and fall, over the midla ds and the south I reckon, with the north staying cold for a while yet