Model Output Discussion - moving into Winter

[Chesil View]

2 hours ago, CreweCold said:

We're seeing a change of direction in the mid-longer term here...one where the HP doesn't completely retrogress but slips back towards Scandi instead.

I'm telling you now, a surface HP forming there could prolong this spell to Christmas, potentially getting more severe. Both the GEM and GFS are attempting to re-amplify towards the E coast of USA/Canada at the same time as pressure rising again across Scandi. They're attempting the holy grail...

Yes Crewe some of the modelling over that last few days has suggested the Holy grail  of the ongoing oscillation of hieghts between scandi and greenie.  Havent commented because I didn't want to jinx the runs. But glad some one else has noticed it too.

Edited December 2, 2022 by Chesil View

[ItNeverSnowsInWindsor]

1 minute ago, Ali1977 said:

That’ll do , what a chart 

Could go all wrong for southern locations opening up the mild Atlantic.

[seb]

ECM and GFS

[LightningLover]

Hmm, ECM 00zis a bit squeaky bum time for us southerners...  (I adore that phrase haha!) I pray it's a wobble!

Edited December 2, 2022 by LightningLover

[Captain Shortwave]

That is so close to being a stunner of a chart at day 8. The only reason it isn’t is purely due to that low blowing up (unlikely in reality)

[Ali1977]

Just now, prolongedSnowLover said:

Could go all wrong for southern locations opening up the mild Atlantic.

Maybe the battle zone, and we love a battle zone  

[Lukesluckybunch]

2 minutes ago, Ali1977 said:

That’ll do , what a chart with another shot of WAA heading up through Greenland. This is gaining traction here, not just a cold spell now , maybe an extreme type event (longevity rather than extreme temps) 

20 minutes ago, Mike Poole said:

 

Is it really that good chart..milder air trying to come in from the south?but we could produce a easterly next

[TSNWK]

But colder uppers washing out.. maybe I’m misreading ecm but personally it’s the least favourite this morning for me.. all very messy and trough losing up ompth over us and uppers mixing out. Sorry for being a bit dolly downer on it

 

[Guest]

Sorry, can't remember who said it yesterday but there were some very wise words about not getting hung up over 850s post day 5  Well worth noting on busy charts like the ECM D6-7... this morning!

[Ali1977]

There’s a big snow event there….a long way off, let’s get the cold in first. 

[carinthian]

Morning all. Well are you lot excited by the current offerings ? You should be ! Many have waited a long time for these kind charts. UK in line for Winter Wonderland.  Now we can start to look for snow. Going back over many years ago the UKMO got snow forecasting predictions with-in 72 hour frame with a rather good accuracy rate especially when Arctic Continental flow was in attendance. This was even without the help of todays more powerful modeling. So a bit of advice look at the charts produced at 72t from the UKMO and for those who want to look for instability and depth of cold air mass , check out Jan Mayen soundings up stream  on Wed 0z readings. I will try an analysis this one for you . Good hunting .

C

Edited December 2, 2022 by carinthian

[Scott Ingham]

1 minute ago, TSNWK said:

But colder uppers washing out.. maybe I’m misreading ecm but personally it’s the least favourite this morning for me.. all very messy and trough losing up ompth over us and uppers mixing out. Sorry for being a bit dolly downer on it

 

It doesnt matter the uppers are washing out its not an easterly. Its a slack trough with probable inbedded features and a freezing ground! It only needs to be -2/-3 uppers in December. The uppers really matter in an easterly off the North Sea. Its an icredible run

[Lukesluckybunch]

2 minutes ago, TSNWK said:

 

I agree that Azores high..looks too strong at 192!

[Eagle Eye]

7 hours ago, RainAllNight said:

Interested if you know what this is @Eagle Eye!! Didn't realise it still existed as recently as 2010...

Teletext I think, my nan used it up until it was deleted,

[Captain Shortwave]

3 minutes ago, TSNWK said:

But colder uppers washing out.. maybe I’m misreading ecm but personally it’s the least favourite this morning for me.. all very messy and trough losing up ompth over us and uppers mixing out. Sorry for being a bit dolly downer on it

 

In reality the low approaching from the south west will be shallower with the jet stream flatter through the Mediterranean Sea. A tad unlucky to get the mild air pushing into the south but the set up is so close to delivering bitterly cold conditions for all and the likelihood of snow for many.

[TSNWK]

Positive air into the south at day 9.. hopefully correction south as huge potential waiting in the wings if the low scooted along a couple of hundred miles south

[IDO]

The GFS control has a similar evolution from the ECM, but the Atlantic low undercuts and we get a cold reinforcement from the north to keep those spoiler lows at bay:

Everything delayed on the ECM, so we end up with temporary warm air in the south. This is way too far ahead to worry about, and we await further runs to gauge what our likely solution is.

[Ali1977]

There’s the battleground at 216 

[mulzy]

1 minute ago, TSNWK said:

Positive air into the south at day 9.. hopefully correction south as huge potential waiting in the wings if the low scooted along a couple of hundred miles south

The blowing up the low to the SW is probably on the extremities of the envelope.  Fine margins here and there.  The initial attack from the north east is slightly too far west.

[Lukesluckybunch]

5 minutes ago, Ali1977 said:

 

I'm starting to get a bad feeling about all this..even at 144-168 it appears most of the cold air spreads west to the northwest of the uk..we need a eastwards shift here..and the whole system needs to be further South

[Ali1977]

That’s a crazy chart, a great NH still and I imagine this run is much more severe than the 850s suggest - midlands north just under a constant snow storm. 

Edited December 2, 2022 by Ali1977

[Chesil View]

Preferring the GEM solution this morning of hieghts rebuilding to our northeast after the initial trough plunge.

[Uncertainty]

Both are the GEFS and GEPS really extend the blocking signal out beyond 300 hours. The latter in particular are quite remarkable.

This is the GEPS at the very end of its run

Such a strong signal for continued Greenland heights!

At 348, the GEFS  still has us in a slack easterly flow 

And  are far colder and for longer than the 18z as a result.

The ecm op is going to be very very snowy, were that scenario to manifest then someone would be under a blizzard.

And the Greenland heights survive. Wild run, unlikely to verify, but amazing to witness.

This cold spell is looking more and more likely and significant.

[Scott Ingham]

Just now, Lukesluckybunch said:

I'm starting to get a bad feeling about all this..even at 144-168 it appears most of the cold air spreads west to the northwest of the uk..we need a eastwards shift here..and the whole system needs to be further South

Between 144 and 168 snow is popping up all over the show with them heights 850s and slack nature of the air. Theres nothing wrong with this run

[Ali1977]

Snow storm as I mentioned