By 144 Ecm keeps the low further south looks great for longer term cold.

All academic. Wait for the next frame. 

I'm convinced this one in particular is going to ebb and flow with the twelve hourly tides of the model output runs.

As I suspected, the low stays south (for now!)

Southern England would be a hostile environment.

Watch the output move around now over the next 2 days, but if I could, Id bank that chart.

http://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=1&type=0&archive=0

 Well I vote for ECM -12 still over the south at da 7

192 ECM getting silly with just how wintry it is. It's very consistent with prolonging the deep cold. let's hope it's playing s blinder.

Those 24-hourly charts miss a huge amount of the detail.

Look on weather.us and you'll see the 850s rise to around -6C in the south, but with a really cold boundary layer in place it doesn't really have much affect at ground level.

The weather.us link to see everything in exquisite detail, snow cover and all, is here:

https://weather.us/model-charts/euro/2018022400/great-britain/temperature/20180302-1200z.html

It would be a bit of a waste IMHO if the cold spell ended with a gradual fading of the deep cold air and a gentle return to normal temperatures. Would I rather have a two-week cold spell ending like that or a one-week spell ending with a monster blizzard? Do you even have to ask?

Of course the ideal would be to get the blizzard and then a renewed hit of cold air from the east...

NE and East too. Serious convection in addition to what is modelled on accumulation charts.

Yes Nick, the ECM is on balance a preferred option generally for prolonged cold and snow.  I think the whole east coast and hinterlands from north Kent to Scotland are going to get hammered if it verifies.

Edit - heres the deep FI 240 chart depicting a cold unstable and potentially snowy picture:

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=1&type=0&archive=0

Amazing detail will have to start looking at these more . Thanks.

ECM amazing frigid to day 10 again reload incoming from the NE aswell  

Bear in mind if you go into the settings on weather.us you can change the units to celcius and the timezone to UTC - it makes the charts much more useable.

The ECM op today paints a severe picture. I've no doubt if that were to verify we'd be talking about a truly historic cold spell.

Quite. ECM is the option I would like for a number of reasons. GFS / GEFS is gentle but increasingly decisive in bringing quite a quick end to the cold spell.

Another tick from me too. I mentioned yesterday that I have seen similar situations result in the attack from the S end up being over France - to the point where we are egging it on to push far enough N to at least affect the far S. I also agree that even the EPS (along with GEFS) will not have this sorted yet because the reality is that the embedded cold can prove notoriously stubborn to displace.

I feel this could be one of those situations where we will see a large swing within the ENS 24-48 hr notice regarding that Low and where it will go.

I really do have a feeling, especially with the METO forecasts, that we will strike it lucky and get the snow and just about remain on the cold side.

No not really. Plenty of snow right down to the south coast but it would likely start to turn to rain by the weekend for the far south and southeast. The GFS snow depth charts actually hang on to quite a bit of snow even for the south suggesting that it would clear before turning to rain too much. 

Detail is pointless at this stage. The general theme seems to be firming up: a low pressure approaching from the south around Thursday night/Friday. Impossible to say how far it will get. It could bring a quick return to milder air or it could miss the UK altogether. Or it could run along the Channel bringing heavy snow but no breakdown. 

There was the famous February 198X debacle. 

For me the GFS is blowing the Low up in situ which is something it has a bias to do, this is an old school spell and those of us old enough to remember know that the first attack never succeeds is dislodging the cold air, but may bring plenty of snow to the far SW/S. I favour the ECM solution of the Lows spinning back and the UK remaining on the cold side until at least day 9.