The Greenland lobe puts up more of a fight on the 12z GFS op run, so it takes longer for both the strat. and trop. vortexes to begin their migration to Scandinavia and/or Siberia.

I can only see the GFSP 12z op run out to day 11 as of writing, but it's already apparent that the split is greater in magnitude, beyond what any recent GFS run has come up with. It will be interesting to see whether the upgrade outperforms the older version in this respect.

I seem to recall from a couple of years back that the models do sometimes move the strat. vortex(es) around too quickly, so it wouldn't be all that surprising if it ended up taking as long as GFS now suggests.

Turning attention to the short term now, and Tuesday afternoon through Wednesday looks like it could bring a fair bit of rain in places as areas of precipitation edge their way northward:

Something to keep an eye on perhaps. As much as half of the totals from Portsmouth eastward are from today's frontal system, but west of that line, all but one or two mm are from the Tue-Wed event.

For a few days later on, the recently upgraded GEM (left panel) continues to give the blocking high more fighting power than the other models do, while UKMO (right panel) is closer to GFS, but it still shows the Atlantic coming up against a wall to the east, whereas GFS has the low heights extending NE from Iceland (not shown):

As a final point, I've just noticed that UKMO also features an Arctic High that could give the blocking to the east an extra edge:

Perhaps this is the sort of thing that led to Fergie's comment regarding uncertain east/west progression this morning? 

Okay, can't resist - this is the sort of strat. split and warming combination those seeking a cold run up to Christmas should hope for:

Just look what that leads to at the surface:

Nicely done there GFSP... shame we have a rough ride before the goods arrive, but better something than nothing 

With so much uncertainty regarding the pace at which things evolve, and this being by far the quickest version of events that I've seen so far these past few days, it's probably little more than a bit of a tease, but I'm enjoying it anyway 

Do us a favour

Stop repeating the model screen shots when you quote someone!

It takes forever to get to the next post, and my frigging index finger is killing me...

The GEFS are worth a look this evening, they're available on the chart viewer:

http://www.theweatheroutlook.com/twodata/datmdlout.aspx

There's quite a range of solutions with high pressure in the mid on a number of them even at the edge of their range. 

The ECM has a large siberian high, I think this is due to the deceleration and warming that either results or results from the warming in the upper strat (1-5mb) we have been seeing (classic chicken and egg problem here).

With this sort of setup there is massive potential if conditions in the atlantic become more favourable; the concentration of the polar vortex in west russia causes ridiculous amount of cold pooling which is clearly visible on the anomoly charts:

The warm anomalies in E russia correspond to the blocking there. In the atlantic there is a fair amount of southern blocking; I don't think it is implausible hat if the jet goes far enough north that some of the high heights could start to transfer to greenland; this would allow the floodgates to open to siberia assuming there are no spoliers on the short wave pattern.

Something more to be optimistic about here, however it is a 240hr chart; that being said I think the blocking we are seeing in Russia can partly be attributed or can partly attribute to the deceleration in the strat. 

Don't know if I should quote and answer that post! (Feel a roll@cking coming! )

Not a million miles away from something much colder.

True. It's only about 2600 miles from my house to the north pole.  I'm undecided about tonight's medium range output. A case of watching and waiting to see what manifests itself in the next few days. There still isn't a signal for a change to colder conditions but something could pop up.

This may not be far from the truth Brian

FORECAST SUMMARY: There are some distinct signs and signals that the forth coming winter will be a potential opposite to that of what was experienced during last winter. There are a lot of factors that point towards the coming winter producing far less stormy conditions and more in the way of ‘blocking patterns’. These blocking patterns are what are often required through the winter to bring cold weather to the UK and at the moment a colder and drier than average winter is preferred.

DECEMBER: Cold weather is expected to develop at times through December, perhaps more significantly so during the middle and latter half of the month when cold weather may well coincide with the Christmas and New Year period. Temperatures, overall, are likely to be near to average through December.

ukwf

Just promise us coldies  if it does look good for cold no polar bears Brian please always goes *its up when you do that,

Despite the endlessly mild synoptics the weather on the ground doesn't feel mild and hasn't done so for many days despite all the blowtorch comments last weekend.

The high uppers are actually producing chilly conditions at the surface even in the South East, I was in London on Thursday and surprised how cold it was, certainly no BBQ weather!

Today in Penrith it's been sunny with near average temps but at 8pm the temperature is  already down to freezing and my car outside is frozen, tonight's ECM promises more high uppers but at the surface will lead to much frost and fog.

Its not mild guys and while the outlook isn't wintry it certainly isn't very mild either and Uncle Barty is nowhere to be seen.

i have faith in the OPI and this winter will deliver.

Andy

Lol that's a pretty big outliner by the GFS for Moscow at the end of the run, sticks out like a sore thumb 

Wow, what a post.

Good thinking Q, I was struck by how progressive the ECM run is with regards to moving low heights away from Canada/Greenland and strengthening the Siberian vortex. The GFSP didn't get to hold on to the 'fastest solution' title for very long did it? 

The LP on the SW tip of Greenland day 10 looks just about sufficient in orientation to promote height rises around Iceland that could link with building heights in the Arctic and generate a blocking high to our N and/or NE.

Takes a bit of luck of course but we would get further opportunities down the line.

ECM's out on it's own limb here so such a fast option seems a low probability - but it does make that GFSP 12z op run, with its very promising charts at the end, look like a far more realistic expectation.

IMO tonight's model runs in general are a slight improvement on those of the last few days in terms of cold prospects. It's difficult to know exactly which way things are heading as there has been a fair amount of flip flopping in the models at times during this month, between a HP controlled outlook and a mobile flow from the atlantic.

Not coming this way on this run, but with the wibble wobble of the runs in this part of the world over the past few runs, I wouldnt be surprised if this ends up over the costa's!

Looking forward to see where this ends up on the 00z :)

That could produce record surface temperatures (for Russia) if it comes off, I don't think I have ever seen the -40 isotherm so close to Europe before. 

Blocking to the east becoming more influential as the GFS runs roll out, and the result is a fragmenting polar vortex lobe in the Atlantic late in the 18z GFS and GFSP runs:

This seems to be along the lines of what I envisioned yesterday (or was it this morning... losing track!) from a more meridional evolution in which the Greenland polar vortex lobe isn't able to just power east to Siberia or Scandinavia.

The GFSP version of events is particularly impressive, and better shows the likely sinking of the Atlantic trough with retrogression of the high pressure towards Greenland as a result.

It's the consistency with which the polar vortex is being modeled to disintegrate that is the biggest positive to take from today's runs, while the favourism for remnants of the Greenland lobe to sink in the western North Atlantic is a close second 

Amazingly, the fairly similar tropospheric solutions above arise despite a large difference in how the strat. vortex is modeled to behave; GFS continues to go for the vortex split becoming undone days 15-16 as the lobes merge together, while GFSP persists in maintaining a quite large split, weakening the two lobes as time progresses. The latter looks a lot better going forward so I continue to hope that the upgraded version, which unlike GFS models the stratosphere right up to the top, proves to be worth the investment in this regard!