P4, 10, 12 and 17 are a bit disappointing and too anticyclonic for Tuesday. 

There is a very small danger that those evolutions are correct, but I think unlikely. Would be just our luck. 

Some of the above still look very wintry later in the week. 

And that’s why I’m not calling it ‘nailed on’ yet.... Even P17 would provides a notable spell of weather imby, though to short and not sharp enough to match recent expectations and certainly wouldn’t be close to a 1991-type spell. 

Actually the notorious P17 is the wettest (i.e. Snowiest) of the bunch for London at least if you look at the precip ensembles. Biggest threat to the South is still that warm air spouting up from France. Biggest threat to the North probably high pressure. But the high pressure scenarios seem to bring in a secondary Arctic Northerly. 

4 and 12 are really quite impressive for cold further out than Tuesday.

what ensembles are you looking at ? P10 and 17 look 2 of the coldest?

...oh I see...that's the point!...too cold for snow....

P17 isn’t especially cold in the near term with maxes nonlower than 3/4c for most... cold but nothing special... Yes, it get colder into week 2 but that’s too far out to be at all confident.

Indeed - was just looking at a snapshot for Tuesday. :) 

18z GEFS a split camp after day 9/10....but I sense the cold camp gained a couple of members since the 12z set, 1 being the op....

http://modeles7.meteociel.fr/modeles/gens/graphe_ens3.php?x=&ext=1&y=&run=18&ville=Londres&lat=51.5085&lon=-0.12574&runpara=0

I think that's a pretty reasonable assumption.

Some cold nights in FI as well:

http://www.meteociel.com/modeles/jma/runs/2018022218/JN84-21.GIF?23-18

http://www.meteociel.com/modeles/jma/runs/2018022218/JN84-7.GIF?23-18

18z JMA. Not fantasy land, just another model showing -12c 850's advancing into the east on Monday.

All models look good midday Thursday, with the core of the cold on Thursday and Friday.

GFS OP:

GFS Control 

ECMWF:

GEM

UKMO (Wed).

18z Ensembles for London: - Cold definitely intensifying end of Feb/early March on 18z ensembles. it is the best part of one week away so could we see more of an upgrade tomorrow or a downgrade!?

Seen worse...

It's not though is it? It has started in the S.E corner with dry Easterly, frost and low DP's. The real cold kicks in from Sunday night in the East and snow cannot be ruled out from then on. Surely that is three days away  - not a week.

At the risk of being the party pooper, I think peeps need to calm the €¥% down re snow totals. People talking about metres of snow etc. The reality will be far, far less for the vast majority. I’m sure that many will see snow falling and some lying snow. Some deep lying snow in favoured areas, but many won’t. Check out Ian F’s thoughts currently on twatter. Solar energy during daylight hours can’t be ignored at this time of the year regardless of uppers. Just pre-empting the nashing of teeth and ‘’ emoticons from those that perhaps should know better if it doesn’t happen for them, and those that are regularly, constantly educated, but seem to have the memory of a goldfish. 

Night all. Hopefully similarly interesting charts for the next three days

Yes true but let's be realistic here! It will be cold this weekend into the start of next week but not unseasonably cold for Feb. The 'real' bitterly cold weather (at least for now) is expected next Wednesday and Thursday with daytime maxes of -2 to 0c for many parts. Perhaps from Tuesday onwards we will see the first ice day for the east and south east. We are not expecting ice days this Sunday or Monday for instance. Say temps will start of with a max of +5c for the south east tomorrow and drop a degree each day so by Wednesday 28th Feb we may be seeing daytime maxes of -1c in many parts with our first ice day of the winter 2017/18. - Typical to have an ice day falling on the last day of meteorological winter.

As for precipitation - We will probably see some flakes on Monday and then flurries between Monday night right through to Wednesday giving dusting's but then after - it's all to play for. I think I know what could happen and I am keeping my fingers crossed that it comes about. 

Just hope there are no downgrades- There could be some changes in precipitation patterns in terms of their locations as well as temps, which will also depend on whether or not there will be snow cover under clear skies or overcast etc - but the overall pattern is still largely unchanged.

Talking of high snow totals, GFS brings the cold spell to an end with a big bang. I mean, really!

Here's the 0z's take on Thursday and Friday next week down here. I've never seen so much snow forecast in one 3-hour period...

Edit: Mean windspeed above 35mph, exceptionally heavy snow... ladies and gentlemen, that's a blizzard in the forecast for Kent.

Of course, most unlikely to verify.

Stunning charts again this morning.  As is usual in an easterly outbreak, especially so one that is severe, FI is  t96. and by 120 there are significant differences in terms of the exactly how COLD and SNOWY each specific location could be,

For that reason,  I am not taking any chart beyond that time with any great degree of seriousness.

As for the breakdown, I've no doubt our resident clowns will start focussing on that before the cold has arrived.  More fool them

Edit - anyone of a nervous disposition in the south should not view the GFS 0z CONTROL. (JFF)

Edit:

A jaw dropping set of London 2mtemp ensembles.  Op is a milder outlier as expected later next week.

http://www.meteociel.fr/cartes_obs/gens_display.php?x=&y=&run=0&ville=Londres&lat=51.5085&lon=-0.12574&runpara=0&type=3&ext=1

Brrr!