If i was cold now, and the charts showed more clustering around a sustained cold spell - then GFS started to throw out a lot of Warm outliers to herald the end of a cold spell... would you start feeling nervous?

Yes - i really would!

Brief cold snap round Christmas.

And here is the February cold snap.

They are all over the shop and change as frequently as a GFS run, but worth a look all the same

A mid/late-December colder snap is off & on more frequently than Katie Price's ...er... wedding ring.

Block again but looks as though it could push the cold blast away

Looks promising:

I was expecting to see the GFS 12z take quite a different path to the 06z- not thus far!

It just fails to push the cold air all the way south, before the high gets squeezed and the cold flow cut off.

However, it's a step in the right direction, I'd say.

Lots of potential for Xmas.

Not perfect for UK cold but some insane blocking from the GFS 12z. Very good signs!

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=336&mode=0&carte=1

It's all about the trends....   well, let's hope so.  It wouldn't take much to turn the 12Z evolution into something nice for Christmas.   I hope it's reflected somewhere in the ensemble.

Indeed and what's good about that run is the blocking gets going at about 150h so not FI really. 

Let's hope it does indeed become a trend.

Whether or not we eventually get a proper wintry spell is one thing, but I'm sure that a pattern change as is being suggested by the GFS would be very much welcomed by all those poor folk that were affected by the flooding last weekend. Fortunately we haven't had any floods where I am, but the ground has been saturated here since early November and probably couldn't take a great deal more rainfall without it causing flooding in my locality.

http://jpwxcharts.blogspot.co.uk/2014/02/ukmo.html 

Well now, it might be just starting to get a bit interesting . . . 😉

All we know at this stage is that the PV is becoming disrupted - how that pans out for us is anybody's guess and any model's guess at the moment.

The 12Z Op produces some of the more appetising scenarios - I will take a bite at that!

I'd say this is fairly cold for us Banbury folk

Great example of how useless ensemble means are in this situation on the 12z GEFS!

http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=12&ville=Londres&runpara=0&type=3&ext=1

(Ensembles for London)

Also, for fun - here's the 120 thumbnails from this morning's ECM. Note how there are already 4 clusters even this early on, there's a lot yet to be decided upstream and until it's nailed down a bit we'll continue to see all sorts in the ensembles and operationals.

(Click for full-size)

GEFS12z postage stamps don't look cold and there's little support for high level blocking. The cold could come but very mild outcomes look a distinct possibility too.

Don't be a party pooper on your own website Brian - you should be cold ramping to encourage the traffic and hits!

I'm guessing the ensemble perturbations are at a lower resolution than the GFS op run? Either way it was nice to see two consecutive op runs showing such potential. The outlook is certainly not without interest and it will be fascinating to see if the ECMWF 12z run hints at anything similar.