Model Output Discussion 29th December - Into mid-Winter.

[Seasonality]

Where is the euroslug? I keep hearing it mentioned yet at 240h I see HP anchored over the bay of Biscay with a trough into Europe. What am I missing here?

[knocker]

The anomalies this evening, despite some 'minor' differences are still very much on the same page.

An intense Aleutian ridge and an active Canadian vortex with a deep positively tilted trough running SW bringing some cold Arctic air with it with lesser trough running down the eastern seaboard. Downstream a fairly flat Atlantic with positive anomalies and ridging near the UK with our ubiquitous upper low to the south keeping the HP honest. The trough to the east is running a long way south to the eastern Mediterranean. The problem still remains the precise position and strength of the ridge as this will dictate whether the upper flow is westerly or in various veering positions. Quite important as the specifics of the det runs will indicate the wintry weather that is liable to swing SE over the UK or further east as systems run around the high pressure At the moment the percentage play would be the HP remaining influential over the UK with the possibility of some colder wintry stuff impacting the north and east. But the caveat as ever is that these details await the det. runs to be sorted in the next couple of days.

In the 10-15 time frame changes appear to be afoot but as to what is not totally clear. To me anyway. The Canadian vortex is still strong but the Aleutian ridge weakens and drifts over the Arctic whilst the vortex lobe swings around Siberia. Downstream the GEFS still has some amplification in the Atlantic but some retrogression has been going on and the trough to the east is now closer and tending to orientate SE of the UK. The EPS is not quite so quick with this but does tend this way at the end albeit with a flatter Atlantic. On this evidence there is nothing more apparent than a fairly zonal set up with some colder Pm shots

Edited January 1, 2017 by knocker

[booferking]

8 minutes ago, Seasonality said:

Where is the euroslug? I keep hearing it mentioned yet at 240h I see HP anchored over the bay of Biscay with a trough into Europe. What am I missing here?

Your missing nothing no slug there and by the look of the charts this coming week a nice easterly & pretty cold temps with plenty of snow your getting enjoy.

[Paul_1978]

1 hour ago, Changing Skies said:

The arctic oscillation is forecasted to go strongly negative to be honest I think it's been years since I've seen something familiar, or my memory is short, suggesting very cold arctic air bottled up north typically - is going to spill southwards to mid latitudes. Therefore I don't find the GFS 12z outlandish in the slightest, certainly a credible chart. 

 

Those AO forecasts don't half flip though. Might be all tanking now, but tomorrow may well show something less appealing. However, thanks for the heads up :-) Going to keep my eye on it!!

[cyclonic happiness]

42 minutes ago, Seasonality said:

Where is the euroslug? I keep hearing it mentioned yet at 240h I see HP anchored over the bay of Biscay with a trough into Europe. What am I missing here?

It's not a Euroslug, more an Azoroslug, it's been scuppering chances of cold weather all winter, and looks to be doing the same for at least the next week or so

Edited January 1, 2017 by cyclonic happiness

[Seasonality]

10 minutes ago, cyclonic happiness said:

It's not a Euroslug, more an Azoroslug, it's been scuppering chances of cold weather all winter, and looks to be doing the same for at least the next week or so

Lol, I was trying to come up with an appropriate netweather style portmanteau word like scrussian or sceuro to descibe it. You've just done it. Azoroslug, love it 

[snowray]

That is of course the predominant feature of most of our winters, Azorslug, Euroslug, Azorslug, Euroslug....Bartlett!

And then its Springtime, all change!

 

Tonights Fax charts, no mistakes this time, very cold air hits Italy and Greece.

[cyclonic happiness]

8 minutes ago, snowray said:

That is of course the predominant feature of most of our winters, Azorslug, Euroslug, Azorslug, Euroslug....Bartlett!

And then its Springtime, all change!

 

Tonights Fax charts, no mistakes this time, very cold air hits Italy and Greece.

And the 528 line is heading straight for Tunisia, what with it being such a cold climate there, they're certain to get some good snowfall *sticks tongue firmly in cheek* 

[radiohead]

That low is a lot stronger at T138 on the 18Z compared to the 12Z.

[radiohead]

Looks like another interesting FI setting up here....

[khodds]

Not much comment on the 18z... I take it not much has changed from the last run? 

[There's a storm a coming]

That's one large high pressure belt on the GFS at 180hrs it runs from Eastern Europe through us and well out into the Atlantic. There just seems no way to break it down at the moment. However the GFS does seem to be following its other outputs of today into FI as it try's to drop the low pressures into Europe and we get colder nw winds. Just like what the ECM would go on to show if it went into "la la land"

tasac

[Chris K]

7 minutes ago, radiohead said:

That low is a lot stronger at T138 on the 18Z compared to the 12Z.

Not sure....in the 'nearer' term it just seems to help promote the Azuroslug into a Euroslug instead 

Pass the  please

[I remember Atlantic 252]

Azores high pain in the a## this run!

[Mucka]

It was an interesting JMA this evening with huge block developing right across Russia and Siberia and extending into Scandinavia

GFS has played around with building a block far to the NE or developing a Russian Siberian ridge and it is back on the 18z

 

So perhaps with the trough programmed to dig into Europe we might start to see a signal in FI for any Eastern blocking to extend Westward which combined with any Atlantic amplification could give us an Easterly.

There was a pretty good signal for an easterly set up toward mid month before our possible cold spell went TU but perhaps we will start to see that theme develop again.

This is all 10 day+ stuff but interesting to see if it develops at all. Otherwise I am going to resume my wait and see. stress free approach tot he output for the time being

Edited January 1, 2017 by Mucka

[radiohead]

Too far east....

[There's a storm a coming]

1 minute ago, I remember Atlantic 252 said:

Azores high pain in the a## this run!

Ironic really as it was the Azores low this week that's been the pain and scuppered the cold spell

[bluearmy]

Sorry to be a bit thick with that chart but if the Azores ridge isn't a bit amplified then we just get last winter? 

the dumbelling ridge is the mid term likely feature to our west

[There's a storm a coming]

At least the last 4 GFS runs have started to move the higher pressure away from Europe. That's at least something.....

They also keep dragging the high westwards each time across the Atlantic. This time it's merging with the one over by Newfoundland. Which in turn should keep the jet on a more se heading

 

tasac

Edited January 1, 2017 by There's a storm a coming

[ribster]

15 minutes ago, There's a storm a coming said:

Ironic really as it was the Azores low this week that's been the pain and scuppered the cold spell

I must be missing something, looks pretty favourable to me, albeit in FI...

Oops, that quoted wrong post, was in response to 252!

Edited January 1, 2017 by ribster
Doh!

[phil nw.]

The problem with a nw/we jet though is the coldest uppers get more and more modified with each successive wave without greater amplification/blocking appearing..Still a below average outlook of course but of limited interest when many are wanting more widespread snow and cold.

[Hotspur62]

That is quite a cold PM flow that pushes right into Southern Europe and reduces Heights down there.Maybe a precursor to a cold spell midmonth.?I think NW UK would get some snow showers in this set up if previous experience anything to go by.Also very High Pressure over Greenland developing and this is a trend GFS has picked up on last 3 runs.

[SMU]

Ha - the most unlikely chart ever goes to the 18z

[feb1991blizzard]

Just now, Steve Murr said:

Ha - the most unlikely chart ever goes to the 18z

Nearly a full house!!!!   -  Only knocker territory preventing it being so!!!

Edited January 1, 2017 by feb1991blizzard

[bradymk]

22 minutes ago, Mucka said:

So perhaps with the trough programmed to dig into Europe we might start to see a signal in FI for any Eastern blocking to extend Westward which combined with any Atlantic amplification could give us an Easterly.

 

Pretty much the end of 18z Mucka!