You need to look at the 850 mb chart as well. The wind has gone round to the east over eastern England, and brought in air that it close to -10 at 850 mb. And with surface pressure so low, there could be copious snowfall.

Kent get's the -10 @ 850hpa

That Azores HP really isn't helping!

P19 my pick - but there are a few non descript options too.

We’ll need a few more days before lighting the beacons on this one IMO, the one positive bring we’re not trying to lock in a three day Easterly but more a longer term cold period with potentially multiple opportunities.

Agreed. And quite right about P19x I’ll bank that one!!

06z para looks very snowy Monday 22nd and Tuesday!

-7 to -9c uppers and daytime maxes of 0 to +2c by day falling to -2c and we have this heading our way..!?

Slider low is similar to the ECM @ 240 hours?

Resulting in this at the end of the day:

Slowly starting to get a tad excited with the output as we head into the latter end of next week and beyond. Whilst where and when it will snow is futile at these timescales what we can say is we’re looking at potentially some very cold overnight minimums as we enter into the final ten days of the month.

06z ensemble chart for London - you can clearly see the 0P run us milder?

London snow row probably the highest it has been this winter.

https://www.theweatheroutlook.com/twoforecasts/ensemble-forecast.aspx?location=London

Also a few trenchers are starting to appear in the GEFS output. 

If I'm hopeful and Solar Cycles is hopeful then that should be good enough for you !

Seriously, I think the GFS will backtrack towards the Euro position. Going forward we have a Euro trough and increasing signs that the Azores High will displace favourably. With both of these factors taken together with EC ensemble guidance, we really shouldn't go wrong.

We really need that OP run to make it's mind up and 'get a grip'!!