The GFSP 12z run has -10°C air almost clipping the mainland as early as +93hr. It has toyed with this idea a few times and has support from some of the other models. The change to more unsettled conditions is almost here as we get closer to mid-month. The details of what comes after is still to be established but the cold air is likely to make its way across the country to some extent at times.

Will the latter stages of this run continue the very consistent signal of deeper cold and more snowy scenarios? I would not be surprised as almost every GFSP run has.

Consistent timescale? Check!

Mid-month change to more unsettled conditions? Check!

Increasing snow risk from the north? Check!

Nailed on cold or wintry weather? Well, that’s a different matter!

Edit: Then the next more extensive cold intrusion is in by 156hrs (again only temporarily’

Good post, Michael. Ties in with my own thoughts nicely.

Gfs 12z op run showing the sort of progression I was hoping to see albeit a few hundred miles to far east.similar to Feb 18 bfte hence my post a couple of days back of possible bitterly cold weather in place by 25th of Jan.
Far to much inconsistency from the model at the moment to be sure of anything other than its going to turn colder next week. Was hoping to see more clarity from the models, maybe para or ecm will provide that. Unless it was the gfs showing its typical progressive nature at showing cold blocked charts when a big pattern change is likely.

Hi Brian

Many thanks, although I am not particularly excited about any of the output at this stage!

Second that. We have great runs from UKMO, GEM, GFS para against the soon to be replaced GFS. I know where my money is 

While waiting for the GFSP I’m happy enough after looking at the ensemble data

Aberdeen http://modeles7.meteociel.fr/modeles/gens/graphe_ens3.php?x=&ext=1&y=&run=12&lat=57.2&lon=-2.3&runpara=0

London http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&lat=51.5085&lon=-0.12574&ville=Londres 

Still barely any bringing the sub -10 air to the south.

Today's ensemble watch - very consistent, really, over the past 3 days. [Bear in mind there may be little in the way of -10C 850s, but the low pressure involved in many of them means that the -10C isotherm is closer to the ground than it would be if it were a typical easterly - this is a very different scenario!]

Click for full size.

Well, the GFSP is now out.

Spoiler: it wasn't really worth the wait! Although it does have a nice snow event around Jan 23.

http://modeles.meteociel.fr/modeles/gfsp/runs/2019011012/gfsnh-0-360.png?12 

A few colder FI's of the 12z run:

I picked out the most blocked and colder runs of all ensembles!

Beginnings of Northern blocking

Well for what its worth snow rows upto 77 now for London on the 12z GFS 

Snow rows down to 53 for Brighton this time. So has to be viewed as a (IMBY) downgrade 

What was the figure from the 6z run?

Very good ecm 192 slider territory could be quite snowy.

71

Runs

Needed

superb....

No sign still of that zonal reset...

The period between T+192 and T+216 would bring a lot of snow to the east of the track of the low pressure.

It's looking very January 2013 at the moment which is a good thing.

Indeed - and it's clear where the Atlantic energy is going beyond that point as well. All academic of course at this range, but interesting trends.

850 temps look a little marginal 

Edit to add... at least down here