I think there will be several amber warning type events during this cold spell, so many little features giving the potential for localized significant snow. 

Tonight some trough potential, if you get caught in a street you could end up with 10cm+! In general though amounts 2-7cm. 

Need to watch the issue of cyclogenesis on any stalling cold fronts in the atlantic, small circular shaped lows pose almost no risk to the cold spell, the issue is when there is rapid cyclogenesis on any of the derbis left behind, if that happens the block could be broken down pretty quickly and we could end up with an awful situ with the high going into Europe. 

Indeed Rob, no complaints from that run, sadly it wont turn out that way........................................or will it?

This run develops a classic three-wave pattern (three main troughs and three main ridges). Such things can play havoc with the strat. vortex which raises the odds of winter having a sting in its tail this year. I live in fear of another March 2013.

Anyway, GFS is still much flatter with the ridge from Siberia, which means there's less to try and hold the Canadian lobe back from Greenland days 7-8. Despite some differences with the way shortwaves are handled days 5-6, the run evolves in a very similar way to the previous two, showing us how we can achieve a bit of an easterly if the low heights across Greenland are not too expansive.

The UKMO solution increases the potential magnitude of any easterly incursion, as the Siberian ridge feeds colder air into the Euro trough while also improving the odds of seeing the whole trough complex slide south, rather than a split with some of the low heights escaping NE, which is what occurs on the GFS 12z op run.

Watching GFS roll on into lower-res and... what's this? The vortex lobe becoming a right mess, the jet disrupting, and Atlantic low pressure attempting to undercut the Scandi High? A better reflection of the background signals for the atmosphere to keep giving the vortex a hard time.

I wonder if ECM will give the easterly idea more consideration this evening, or continue to point toward another major trough import from NW of the UK?

Given that GFS gets where it does for days 9-10 by powering energy NE (from S of Greenland to Svalbard), it may be favouring that over a renewal of the Euro trough as a result of the usual bias (a tendency to choose the NE route remains from what I've seen over the past month).

In light of this, GEFS may lately have been displaying a similar trait but in combination with most of the perturbations showing more expansive low heights to the NW, this shoving the UK/Scandi ridge down to our S or SE instead of allowing it to hang around.

One can but hope, Marcus.

The NASA GEO5 0Z ends with a square one reload! In case anyone is wondering the uppers are between -8 and -11!

Still poor imby for snow 

GEFS show's it well soon as any meaningful precip is shown the 850's rise and it will be rain/sleet 

http://modeles.meteociel.fr/modeles/gens/runs/2015012812/graphe3_1000_277_91___.gif

Some places to the north could see a lot of snow where the shower trains set up in the next few days

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/01/28/basis12/ukuk/prty/15012912_2812.gif

No hint of an Easterly from ECM, a reload from the NW ??????

ECM shows us the middle finger 

http://www.meteociel.fr/modeles/ecmwf/runs/2015012812/ECH0-216.GIF?28-0

That's a very deep low coming out of America. Will it raise heights over Greenland or just steamroller its way through?

Probably the worst of the 12'z's

Lets be honest we were bound to get a reality check at some point.

Hopefully it wont set the trend and start a big turn around.

Poor ECM. I think this Easterly block is another fantasy. Lets see how many ens members still have it

That ECM run is actually very close to being very good. Certainly within the realms of correction come nearer the time.

You don't know that yet though, Id wait to see where it sits first

surely if the ECM is deemed 'poor', out expectations are rather inflated... Day 10 actually looks very wintry with sub-6 850s and sub522dam air with a LP just to our east... How it would evolve after that is pure speculation... Indeed, it's little more than speculation after day 6 anyway!

In....... fear????

A great month, was March 13