Always speculation beyond several days but the ENS are and have been pointing to less cold and then average for quite some time now:

London:

2 clusters appearing at the 5th i.e will pressure build as seen in some runs or will the Atlantic break through? Combined with Meto outlook, ECM op and GEFS, I'd probably say that a gradual return to average is on the cards by the latter half of next week.

To be honest Mike with the scenarios shown in the NWP currently the t850s in isolation are next to useless.

They could show a mild SWly or an inversion and there may be little difference in the t850s. I think it would be a brave person to call an average outlook currently.

I did try to explain this the other day. Our parent low has some milder air both at surface at uppers caught up in it, dragged up into Scandinavia and as the low sits to our east it's then pulled back down on its western flank. The higher theta-e values and absolute temp translates to about a day of raised temps and lower snow chances. This will clear away Saturday and values generally fall again into Sun/Mon

In short, a region of less cold air trapped within the low pressure system is headed our way on Friday, in fact it is warmed a little further by interaction with the Atlantic ocean (which has surface temperatures of 9-10*C) before it reaches us.

This tends to be more of a problem when low pressure is moving across the UK, as is the case with a small secondary low on Friday.

Ah - I see Neil beat me to it! 

Milder air has been advected northwards on the eastern flank of the low pressure. There is currently a pool of this to the NNE of the UK (850's of around 0c)

As this milder air circulates anti-clockwise around the low, it mixes with the colder air from the NW which mitigates the mildening effects somewhat - but not completely.

We therefore get a slab of milder 850's moving southwards down the western flank of the low

Edit: run this animation and you'll see it clearly - http://www.meteociel.fr/modeles/gfse_3d.php?mode=2

So what about ECM... it's 12z op seems very similar to the GFS 12z op out to day 8, the main difference being that the low heights don't push so far NE - which is what I suspected we would see if the GFS solution is linked to it's progressive bias.

The trough disruption signal does then appear, but takes place to our NE, resulting in the Siberian High teasing us while the Azores High quite literally squares up for the fight.

Plenty of room for a push from the east some days later on, but it looks like it would be a rocky old road to get there. Take away that bomb to the SW of Greenland on day 9 and I reckon it would be a more encouraging outlook.

...but never mind that, some x-rated imagery has made it past the blockers:

This happens largely as a result of the trough over Newfoundland on day 4 being unable to pull itself together properly, disrupting with low heights extending SE to prop up the mid-Atlantic ridge and have a crack at turning into an omega block (where the jet follows a pattern similar to that Greek letter - a ridge with slow moving or stationary troughs to it's SW and SE).

As for that strong Channel Low, it's playing with us, surely? 

L P out to West A Deakin mentioning this , still uncertainty about its track

This seems my best chance of snow laying in the next 7 days

Very marginal dewpoints. http://www.wetterzentrale.de/pics/Rmgfs368.gif

You'd have to say that looks like rain. http://www.wetterzentrale.de/pics/Rmgfs362.gif

NMM 6z has a streamer setting up across parts of southern England later tonight. This could produce snow for some

http://modeles.meteociel.fr/modeles/wrfnmm/runs/2015012806/nmm_uk1-1-21-0.png?28-11
http://modeles.meteociel.fr/modeles/wrfnmm/runs/2015012806/nmm_uk1-1-22-0.png?28-11
http://modeles.meteociel.fr/modeles/wrfnmm/runs/2015012806/nmm_uk1-1-23-0.png?28-11
http://modeles.meteociel.fr/modeles/wrfnmm/runs/2015012806/nmm_uk1-1-24-0.png?28-11

A more organised band of showers moving through around lunchtime tomorrow could also bring snow to the south. This is shown on the BBC forecasts as well.

http://modeles.meteociel.fr/modeles/wrfnmm/runs/2015012806/nmm_uk1-1-31-0.png?28-12

Possibly up to 5cm of cover in those parts affected by the streamer if this comes off. Elsewhere 0-2cm across the south. As these are all showers it will be hit and miss with some places seeing nothing at all. It is all very marginal for the south. Some places may just see rain / sleet.

http://modeles.meteociel.fr/modeles/wrfnmm/runs/2015012806/nmm_uk1-26-36-0.png?28-12

High res German ICON model shows a nice arc of precipitation tomorrow night running from off the west coast of Norway down through central parts of Scotland towards the Lake District and then arcing south-east through the Midlands towards East Anglia.

http://modeles.meteociel.fr/modeles/icon/run/icon-2-39.png?28-12
http://modeles.meteociel.fr/modeles/icon/run/iconfr-2-39.png?28-12

GFS18z shows a similar picture. Looks like this could be largely be rain though away from high ground
http://modeles2.meteociel.fr/modeles_gfs/runs/2015012818/33-779UK.GIF?28-18

Beyond that most of Friday and Saturday look dry away from the coasts.

I spotted that earlier. Pretty much perfect alignment for me, if it comes off.

the 21:55 forecast showed it as Snow Rob

Good stuff, fingers crossed then. Hopefully being overnight will help keep the temperature down!

This could also be Snow but no mention on the Beeb......too far out no doubt

Some harsh frosts on the way

Very cold days also

Cold air clinging on

Temps higher by Friday , very different to the 12z

Fax charts are very late tonight

The Precipitation type chart for 3pm this Sunday:

I know what happens when you follow these charts, it's always inaccurate, so as always to be taken as a foot of salt!

The BBC Northern Ireland weather forecaster at the end of the 10.30 bulletin said that, after things turned more rainy/sleety on Friday, there was already a Yellow warning in place again (for Northern Ireland) for snow for the weekend.

There is. It's been on the MetO website since 17.50hrs this evening.

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1422662400&regionName=ni

Latest 96h fax

latest 120 fax chart

Struggling to see how the weekend can be dry with fronts moving down the UK

The E4 model highlights why its particularly frustraing living in merseyside or south lancashire during cold spells.

Everywhere else doing ok,