although we are quite high up compared to surrounding countryside, our house is South facing so any winter sunshine, like today, is a bonus. It's glorious seeing the sunlight stream into the living room.... So much so that I have taken some lumps of coal off the fire that hadn't started to burn yet. 

LOL

Thanks all  Yeah, agree with Darren and others sentiment over crisp sunshine over grey and raw

Over on the other site... Tamara's been posting some highly detailed analysis and projections as usual, always worth a read. I'll see what I can translate for the general public (my comments in usual typeface below each quote):

Posted by Tamara on 22nd December, when the easterly was just starting to gain some ground in the models:

"The unreliability of the modelling and pendulum swing attempt to ignore the background atmosphere drivers seemed obvious. The manifestation of this misread of signals was the apparent flip to much more consensus for flattening out the pattern over progressively to a zonal one, and should not have seemed convincing in the circumstances. Any further such modelling, in prevailing circumstances, should continue to be viewed with suspicion - until, or/if those circumstances change..."

It looks like she was right about that one, at least based on recent trends.

"However this plays out, the -AAM /GWO phase progression forecast feedback (as long as it persists) continues to offer support in providing wave breaking mechansim to undermine the vortex and mitigate associated westerly energy in the northern arm of the jetstream while the vortex remains weak, but alive. There continues to be a great opportunity for a New Year polar vortex bonfire."

'This' was referring to the sliding low and potential cold conditions in its wake. The -AAM/GWO phase progression forecast feedback is, as far as I understand it, a process which in the coming two weeks looks to produce periods of reduced westerlies (i.e. jet stream strength) interspersed with short bursts of higher momentum. The 'polar vortex bonfire' is just a fun analogy for the vortex disintegrating in response to the wave breaking into the stratosphere (waves of relatively warm air that shove the vortex around and with enough intensity can split it up or even break it down completely).

Posted by Tamara today:

"So, those attempts, especially by the old prototype GFS, to prematurely flatten the pattern are proving as wrong as they seemed

 As suspected in recent days, the continued drive forward in -ve tendency AAM and consistently predicted dotted progress of GWO through Phases 1 and 2 at the close of the year fully support the increased amplification signal in the Atlantic which has gained modelled ascendency over the last 48 hours - with ridging into Scandinavia, on the back of the SE tracking low next weekend.."

This is the explanation for the dramatic shifts in model output we've seen of late - it was all starting to look good, then some incoming signals were misinterpreted and seemed to slam the door on all the positive signs, but then the signals came through properly and the output dramatically about-faced toward perhaps the most positive outlook so far in terms of longer-term potential coupled with shorter-term cold conditions while we wait.

"Progress into Phase 3 supports, as we start the New Year, some westerly push increasing Atlantic influence thereafter as some vortex energy heads back over the pole towards Canada - but this is where it might get even more interesting as we look at undercut potential of heights by this time bedding in over Scandinavia to UK."

It's the GWO progressing to phase 3 that is being referred to. The remainder of this section is straight forward... and a right old tease 

"The -ve frictional torque which precipitates the -ve mountain torgue over the US (wave 2 breaking) which in turn forces the GWO through phases 1/2 signposts the positive momentum transport indicated between 50 and 60 degrees north - but also it supports the increase in easterly trade winds indicated around 30 degrees south which increases sub tropical Jetstream flow."

This is referring to the way in which, with the right airflow, the mountains can divert warm air up into the stratosphere, which is the wave breaking mechanism. The next bit covers how the same process moving the polar vortex to Canada with a burst of Atlantic westerlies should also bring about a stronger subtropical jet stream.

"[The enhanced subtropical jet signal] underpins latest ECM suggestions of split Atlantic flow in the 10 day + term and support for maintaining the blocking structures across Scandinavia into UK.  On this basis, we should view any modelled sinking of the cold high to be over progressive, (and short-lived should it occur, at the very least).

It translates to an excellent holding pattern of surface cold while the stakes on that New Year polar vortex bonfire rise ever higher to get arctic upper cold towards us.

Could we be cued for a cold anticyclone waiting to be sucked northwards by Arctic/Svalbard Heights as zonal winds across the polar field dive to negative reverse polarity in response to the combination of wave 2 uppercut from the troposphere (MT) and then next, a singeing head blow this time from the upper stratosphere?"

In short, a lot of potential for the jet to undercut the blocking high and sustain in in-situ with perhaps a tendency to shift to higher latitudes as we move into 2015. This then leaves us very well placed to benefit from the strat. warming events being projected to unfold... but of course it all relies on the GFS/ECM strat. modelling being close to the mark, which needs GFSP to be off on one.

A very wordy post I know, but I felt it was worth having a go at translating such excellent analysis for the benefit of those who aren't familiar with all the technical jargon 

So the pub run was actually right? 

Great job, James.
Now go and get a mince pie and a glass of port and put your feet up - it's Christmas Eve man!

We need to watch boxing day for potential significant snow event. Its on a knife edge whether snow is possible on the northern and eastern edge of this system. GFSP6z

Looks like it could just be about cold enough as that system moves into the cold air from the west. My precip type parameter has it 50:50 for the north and the east. 

Looking increasingly chilly over the weekend and possibly a little less unsettled (or at least a little less stormy) than previous runs on the 12z GFS op run so far http://www.wetterzentrale.de/pics/Rtavn10817.html

Beyond that will we have high pressure over Europe again with chilliness for the SE?

Already a big difference at +96 between the old and new GFS. Such divergence will surely make the programmers think twice about reverting to the new algorithm in January?

We have her partner 'James' (know as 'Jam') over here. They're close friends of the GFS chart writers. You'll see them mentioned a lot when there's snow just around the corner...

That Norwegian shortwave on the GFSP may work in our favour with an opportunity for a better placed Scandy ridge building behind it.

PS: I'm ignoring the old GFS today - not confident in it lately and it should be retired shortly.

New GFS is the way to go, I'm confident.  (Copyright G Sarre)

Stick to the EC and UK MODELS up to 5days ahead and you'll get a basic idea of the week ahead been doing it for 10 years now. Forget the American model unless in the 2-3 day range for extra info. Euro is the chart of choice other side of the pond too

Thanks :-) 

never seen a "Jam" posting here lol. Only James I was aware of was storm... 

So are they professional or amateur forecasters?

"It's always Jam Tamara"....

Whoosh!

Tamara is an amateur (AFAIK) who's rather into the techie side of things.

Or maybe not LOL.

Very knowledgeable , has some excellent posts on the other side.

Disappointing runs so far today. High seems to be a slow sinker.

Take a look at the UM this evening. Looks like it's been on the port and cigars already. 

Not quite professional myself, but I have a masters in meteorology which tends to prove handy 

The outlook for the weekend seems to have again shifted a little colder, but with less low pressure development which further limits the snow potential, mainly to the eastern coasts.

The 12z GFS first has that sliding feature heading too far toward the Eastern Med. to do us much good (less of a cold feed) and then blows up a shortwave near Iceland at +132 hours which causes the massive blocking high to topple. Shame on that model for being such a Scrooge 

Meanwhile, GFSP keeps the low further west, which is also true of UKMO. This means a bit more cold continental air in the mix across t the UK, so better for some interesting frosty landscapes where skies remain clear.

Neither have GFS's shortwave, and GFSP maintain the large blocking high right out to day 10... but this 12z effort insists on maintaining a strong jet up the western flank as is most visible on the day 9 chart (below-left):

Contrast that with the GFSP 06z which was at the other end of the scale - jet powering right on underneath the blocking high.

The divergence from the 06z with regards to that jet going north starts in about 4 days time, the reason for which seems to be nonexistent... no visible change in the horizontal temperature gradient, for example.

The fact that the jet is nearly always toned down nearer the time may prove very beneficial provided we do get the UK block in place next week.

To summarise, the weekend snow risk seems as low as it's ever been due to the low not developing as much, while next week sees an 'in-situ cold' scenario remains the favourite, with the tease of a more notable easterly by GFS and GFSP dropped on their respective 12z op runs.

As for the elusive Atlantic trough disruption and undercutting jet, you have to seek out GEM for that:

Cheers, GEM! All thanks to the jet splitting days 7-8, and of course GFS's biggest weakness is that very process 

Right, where's the port... Merry Christmas everyone 

rofl the GEMs solution is completely different

Merry xmas everyone. Here is a GFS boxing day snow chart which some people in the Midlands might appreciate. 

Also Holy Rao, has anyone seen the JMA! Talk about lack of total agreement at 84hr! 

 You have an 'ology'? - that's fine by us  (older viewers might be having an advert memory jogging moment now )

I went into my local Off Licence just as he was closing. I said "Can you recommend a good port?" He said "Yes, Dover, now p*ss off back to France!"