P7 does it's best to keep P20 company too:-

 

Clearly trendsetters rather than massive outliers

In the near term mild, unsettled sums it up, with hints of a cool down towards average in time for Christmas.

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Definitely for you Mike! It would be snow nirvana and I would look forward to seeing your pictures. 

For us down sarf, even some chillier nights would be most welcome and a frost if we could stretch that far, we might just get this if it does get cooler at Xmas.

 

Ps: those you posted the other day we great...... 

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fwiw  Santa wont make it in that head wind

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=222&mode=0&carte=0

 

 

Seems to me that the ECM 00z op run is probably an outlier, having just checked it against the ECM mean charts.

That said, were the ECM op to verify, it would provide a few days of very welcome relief for those poor folk who were affected by the flooding following storm Desmond last weekend.

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Yes quite a shift in GEFS ensembles  from Zonal:Anticyclonic between Xmas day and 384h. Xmas day Zonal 90%Anticyclonic 10%,384h zonal 55:anticyclonic 45%. 

Mean can be a little diluted at that range but having said that David pressure always far to high to our s/e imo

http://www.meteociel.fr/modeles/ecmwf.php?ech=192&mode=1&map=1&type=1&archive=0

ukmo looks similar to our s/e

http://www.meteociel.fr/modeles/ukmo/royaume-uni/500-hpa/144h.htm

 

 

Don't worry, if the worst comes to the worst, Santa could always ask Peter Capaldi for a lift in the TARDIS on Xmas Eve night. He'd be safe enough in there!

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That Arctic high needs watching it could well yet affect our weather post xmas 😉

 

On this run it gets blasted away...and to continue the trend of posting deep FI charts, here is the 6z Op offer- a euro-Bartlett special

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This is a long way off and only JFF: But there are quite a few interesting charts in January AND February - WHICH SHOW quite a change in our weather pattern:

If and A BIG IFF - WE Could see and SSW end of January IF' these materialise?  - Perfect set up  -HP blocking to North and LOW to south! But this may not even materialise and who knows what could happen.

Once again JFF:

HP trying to build over Greenland:

 

The best I have seen:

 

Let's face it - the longer these horrible drap, dull, drizzly mild 14c day time and 13c night time temperatures continue - the greater the chance of colder weather in mid-late winter IMO.

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ECM is a massive outlier, ens mean very different at 192hrs

The charts are showing some similarities to 13/14 dare it be said, with a powerful vortex and a southerly tracking jet. A stormy Christmas looks like the best bet I think.

How quickly can we go from a flat jet and strong polar vortex to blocking? Can anyone give an example of a really quick flip?

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I wouldn't google that up if I were you, especially if the filter is set to "unmoderated".     

I expect Kevsbradmrdata is your man . . . in terms of past synoptic references, that is.

Back on topic, looks like being the same old same old in the run up to Christmas, especially as the mid-Atlantic jet stream is set to fire up a bit more and the stratospheric set up is expected to stay unchanged for a while. It's going to take nothing short of a miracle to get a pattern change out of all that at short notice.
  With that to mind, I've already resigned to the fact that it's going to be yet another green/brown Christmas, at least for this end. The only thing I can hope (not that it'll change the output) is that we don't end up with a windstorm type set up associated with cyclogenesis developments aka Christmas 2013. I remember how rubbish that was, even though it actually turned out fine on the day itself (a brief respite in between stormy spells).

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Not a "massive outlier". Just at the cool end of the peloton:

http://www.weathercast.co.uk/services/ensemble-forecast.html

There are one or two properly cold outliers at that point.

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The Xmas/New Year period of 2012/13 was very unsettled and fairly mild as far as I remember, continuing the theme that had dominated much of 2012's weather. I can't recall though what the state of the polar vortex was, but I think there was some stratospheric warming taking place around the time which played in part in changing the prevailing weather pattern as we went into early 2013. From the second week or thereabouts of January 2013, the weather became very different to what it had been at the tail end of December 2012.

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Best to keep an eye on the jet profiles atm- I feel we could be heading for a very zonal spell around Xmas with notable storms. Could get quite cool up north too with some of the fabled Cold zonality at times- but there are in my opinion hints at a pattern change in about 7 to 10 days time. If the PV does get displaced, don't be surprised to see it move further South bringing some very direct Atlantic driven weather our way. All of this IF Euro HP wanes....

It wouldn't surprise me and it would be fairly typical to get a very unsettled spell at or shortly after Christmas (based on the singularities)

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Late Dec '12-early Jan '13 was certainly a mild period. We had temperatures of 13C in early Jan, and overnight lows of 10C - which is remarkable for any winter month let alone January. The change to cold was rather quick.

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January 1947 I believe

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Apologies if this has been covered previously, or if it is a stupid question, but is it necessary to have a SSW event to get a prolonged cold spell?

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No, but it helps. I don't believe there was a SSW before the December 2010 epic cold spell.

1947 is really odd; I note for the first week of the cold spell the polar vortex is almost entirely in tact, and the cold that the UK and europe is in seems a little like a rock in an otherwise perfectly flowing stream. I'm amazed that such a setup doesn't collapse and is not reabsorbed into the main polar vortex. It could not be more different to the annihalation we see in 2010.

This is insane, look at the arctic; the polar vortex is completely unharmed. It does later collapse, but for the first week of the cold spell its like this. 

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January 1985

Indeed. I might be wrong here (and someone please correct me if I am) but I don't think there was any SSW in late 2009 either before the start of the late Dec '09/early Jan '10 freeze.

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The 2010 SSW occurred in Feb, i.e. after the cold winter.

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