Central Southern England below the -4C upper temp from +162 until +288 on the GFSP. The Parallel is something else! That pesky mid atlantic low that somewhat scuppers the GFS Op disappears. The GEFS will be interesting. Some pub run that! great day's viewing.

Control thus far holding that high off looks better than opp my projector getting red hot now 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=174&mode=0&carte=1

One important point to remember as we compare the GFS and GFS(P) runs is that the upgraded GFS (i.e. the parallel run) now goes out to T240 in high res. The GFS op run only goes to T192 in high res. 

This is illustrated well in the 18z run. The GFS(P) keeps the cold weather going right through to T240. Immediately after this the Atlantic blasts through as soon as the run goes to low res. So ignore everything after T240.

GFSP is insane:

Heavy snow for the SE, and thundersnow showers in the NW. Nothing that amazing for us in the east though :(

The 18z GFS op run is rather tragic almost all of the way through really in terms of wasting potential... but at the very end it manages to amplify the pattern and start building a Scandi High (http://www.theweatheroutlook.com/charts/gfs/18_384_mslp500arc.png?cb=292).

It usually takes strong signals for GFS to attempt that sort of thing so far out. In this case it's the Pacific/U.S. pattern remaining strongly amplified.

I'm pointing this out because it also remains amplified on the GFSP run, so the cold is only really undone by storms bombing out all over the place, which I've noticed GFSP tends to have a habit of doing once into lower-res.

So there's reason to remain hopeful even if the final-week cold ends up being close but no cigar.

Still, I'd sooner have the 18z GFSP higher-res output to get the ball rolling  

As I said about the GFS 06z which was similar to the 18z, runs like that were cropping up prior to November 2010's onset of cold. It's something I made a serious note of at the time and swore never to forget so that I could fall back on it the next time a similar pattern turned up in the model output 

On the other hand...

Yes, two cherry-picked charts for Christmas Eve (I can only find four others with similar or greater potential going forward), but I felt that the other side of the coin needed to be seen, these showing how we could see upgraded towards something nearer the GFSP solutions.

Sorry to say that sometimes I'm tempted to delete these one-sided one-liners or at least add a few words to balance them out 

Good news from the Meto

Ian Ferguson Netweather

No, as I've previously posted, the view remains a likely post-Xmas phase with high to W, trough to E; exact alignment of flow yet tbc but the EC 12z clusters from ca. 28th out to T+360 remain supportive of trough axis close to E (or even over) UK, with varied NW/NNW/N'ly solutions (and associated low centres) of varied 'potency' into that period. Broad-brush approach applies for now of course (worded as 'possible colder spells' or similar I'd imagine, which suffices until we can see some consensus and detail).

Have a look at that one Q insane

http://www.meteociel.fr/modeles/gefs_cartes.php?code=4&ech=252&mode=0&carte=1

Are you Dicking around with the sepia, etc, setting on your phone camera? Have you added these 1960s psychedelic colours or are these odd charts actually IN these colours?

Is there some sort of legend? Not meaning to sound critical, but other than the obvious pressure patterns, the colours mean nothing to me at all. Apologies if I've missed this info in earlier posts. 

Well to sum up today's model runs I think the key points are;

1. Overall a firming up from the model output of a likely cold spell/period from Christmas onwards;


2. Potency and longevity of the likely cold spell questionable and dependent on how far North/South you are in the UK;


3. A marked divergence in output between 18z GFSP and GFS Op runs; and 


4. Very different opinions from learned posters on here in terms of the way this is heading.

In other words, there's is potential for something cold post Christmas but nothing is nailed on.

  I like the colours that's why I picked them (yes, those are the actual colours of the charts) !

Tbf though I would put the background image in the first one as white rather than black, but idk if I can be bothered to put the effort in. 

There is a legend for the 850mb chart, its on the right.

I've edited my last post as you posted. Is there a legend? I can see the isotherm one, but the bottom one has confused me. I feel ill as it is and this is just giving me a migraine 

Green is rain, blue is snow.

There isn't a legend because firstly the precip is in a log scale and 2ndly there are two types. The colourbar script I am using is incapable of handling this. It means I'll be forced to write my own, which I don't know if I can be bothered to do.

I see what you mean:

What can I say, I like them! Also of the 3 charts I could have sworn the lake effect one was the most controversial, and that one seemed to pass the mattyH test.

BTW- Jamstec have gone for a cold UK in their latest update. 

WOW

GFS P is A Stunner,this morning plenty of

C.S

The GFS ensembles are now starting to get 'that look' about them.

ECM is far from convincing and ends mild for England and Wales (though not as mild as today's blowtorch): There are some much colder charts around, but as  I am far from convinced the cold will really get much of a foothold south of 55 degrres north in the post Christmas period, as things stand in the models.  So Im posting the FI Op from "the most reliable model" rather than the 18+ attractions of the GFS P.  It is interesting model watching for sure.  I would say remember the key (for some confidence of snow)  is cross model concensus at 144.  And that is cross model concensus for deep cold to be embedded, not "on its way".

I do think at the moment in the post Xmas period the trough of low pressure in the Atlantic will keep the S of the UK on the warm side of the polar front.  I realise this is just one possibility of many, but its my call at present.