Just looked at 06h GEFS out in FI (360H).6 Jan

Majority of ensembles (66%) still zonal W or SW., No convincing cold. HP in a variety of places UK,W Russia,Atantic Greenland.but no sustained cold flow over the UK.

Wilhave to hope that LP tracks shift further south.

ECM and MOGREPS ensembles give strong support for the low crossing the UK late on Christmas not quite cold enough for low -level snow even on the Northern side, above 300 m I think

Yes, I agree. To get snow at lower levels, some stagnation would be required. For that we would need very low heights but no circulation on the surface. I would say parts of the south midlands and SW are most at risk of seeing localised snow, but I recon its still less than a 1/3 probability at best. 

EDIT: The GEM solution is most conductive to transient snow in wales and the SW. 

No 8 would be very close for the s/e Q very wet mix but it would count

http://www.meteociel.fr/modeles/gefs_cartes.php?code=8&ech=108&mode=0&carte=0

Possibly snow for those of us in the North and West on Christmas eve 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/2013/12/21/basis06/ukuk/rart/13122406_2_2106.gif

I think there is too much circulation on that pertubation to give snow, although perhaps on the chilterns. Having said that pertubation 6 does offer some snow potential for the 27th, potentially even quite widely. 

not a clever xmas eve fax chart for travel

http://www.weathercharts.org/ukmomslp.htm#t72

Will feel very cold in that wind Alan

http://www.meteociel.fr/modeles/gfs/royaume-uni/vent-rafales/90h.htm

Looks rough enough though,eitherway.

Sorry,Eyeballed it wrong.

Specsavers and all that.

Here is a quick sounding check for England midday at 12pm xmas day based on the 6z high res GFS. Obviously forecasts assume precipatation is about, but anyway for a few cities:

London: RAIN

Norwhich: RAIN

Southampton: RAIN

Exetor: RAIN

Cardiff: RAIN

Currently doesn't look too great :S