It's all looking a bit December 1978! A blob of -12C air over the country and heavy ppn heading into the SW.

I think Tally has designed this one! 

If I was asked to draw a synoptic series that could deliver a major snowfall across much of the U.K., those GFS charts from 180 would be close.

Deep cold air in place and across the near continent. Moisture and energy approaching and disrupting just off to the southwest. That has the makings of a significant event (screengrab - it won’t be there later)

Excellent GFS 6z for coldies. Not quite a full fat easterly but very close. 

Undoubtably the best runs of the winter so far Brian.

Again - Leaving aside FI which keeps flip flopping!

NextwTuesday 22nd 

This is a re 0ccuring theme now - the front slows down and stalls from Midday Tuesday into Wednesday:

Seems like we could see hours of wet snow, sleet or rain to snow or even heavy snow and accumulating snow - Temps of 0 to +3c widely by day and night - Some places could see a lot of rain or a lot of snow or slush etc - depending on how heavy the precipitation is, there could be time for convective cooling in many southern area's if the cold air digs in behind the front!!

Whilst this is a very good Op run, we need to watch something that might go unnoticed. At day 8, that low over the Baltics has been shown deeper and more east of us on each of the last two GFS Op runs. Any more movement of this further east/north could leave us in a cold col, around 26th, rather than in a NE flow. The danger is the really cold air advects south not west to us. I’ve seen this before - really cold heavy air has the knack of behaving unpredictably.  Just saying. 

Jeff

Brexit might not be the only issue the government have to deal with were this run to come off!

Only my opinion, but the GFS 06Z almost looks reminiscent of what happened at the end of last winter.

Incredible that we now potentially have Easterlies in the frame for a second consecutive year after a prolonged absence.

Are we now in what you could call the ‘postmodern’ winter?  

It happens towards the end of the run. What is starting to become clear is that the pundits regarding February could be bang on the money.

Cant wait to see the Ensembles. I am keen to get rid of some of those irritating mild members

Exactly Jeff. Those winds are more from a northerly as the SE low is further away on this run. Quite a low forming at 240 South Spain which might come into play later.

Edit: It does but gets interesting again later on.

I agree Michael, Doc.

We are being shown very cold NW then NNE winds if we look at GFS 06z, And it looks like that NE USA NW Atlantic Low is expected to track a bit south of NW of Atlantic, with later Jet energy plunging SSE from it- it helps give handshake of energy for NNE flow by Thursday to Sunday based on GFS 06z, and then UK could see SW West Europe see SE tracking PV Low with NW France UK stay on cold side of Jet that allows further chance of heavy snow in South SE UK etc, by 27th-30th January 2019.  

Further Cold Low Pressure for NE USA by Thursday to Saturday is possible with high pressure building back over Greenland in fact it looks a potent block even by Wednesday to Friday next week.

Upgrade in terms of snow potential for the south: 

Very slim and unlikely scenario but it's a possibility of course?

Hi all.London ecm ensembles looking cold then some spread the further you go out.Have a good day.

Very similar charts and set up to 6th Feb 1947: - Just a stronger Greenland block of HP back then, that's all otherwise an identical chart with LP over Baltics, HP north and LP taking a southerly track undercutting the high etc:

27th Jan 2019:

Looks like the GEFS are trending colder.

192hr mean 850s look good:

And the mild stragglers have almost vanished in the first half:

AGAIN MORE SNOW POTENTIAL for the south:

Again with the 06z Para:

Much snow potential for much of the country Tuesday 22nd night into Wednesday 23rd as the frontal system stalls and sinks southwards allowing convective cooling:

GEFS 06z look cold or very cold.

https://www.theweatheroutlook.com/twodata/gefs.aspx?run=na&lg=850&lglocation=london&charttag=PS%20500hPa%20(GPDM)

Another way of looking at things! The Average/mean of all 20 ensemble runs at 300z from the 06z: - Looking from the N, Pole down.

LOW pressure over the English channel dragging up winds from the very cold near continent - Blocking to our north esp over Greenland - This could denote heavy snow for many?

Mean now down to -7C in the midterm. Best ensemble of the winter.

I haven't gone through the individual runs but this mean pressure pattern at 300hrs looks pretty promising! (I see Tally beat me to it on that one)

And looking at the tabulated runs, it's noticeable that even the few runs that go mild in the medium term then go cold or very cold (-10C) later on. http://www.meteociel.fr/modeles/gefs_table.php?ext=1&x=&lat=51.5085&lon=-0.12574&ville=Londres