http://www.meteociel.fr/ukmo/runs/2017011912/UW144-21.GIF?19-17

UKMO now in line with GFS with a more amplified ridge. It will still be pushed aside on Friday, but another week of frost for some areas

As for two weeks of zonal, I said I hoped it only lasted that long, I wasn't saying it would but we know that once the pattern is set it can be hard to shift it

it`s only a couple of days ago the Atlantic was pushing in on Sunday/Monday a sure sign not to trust the output too far ahead.

I believe any Atlantic thrust will again be short lived before high pressure rules the roost as we head into Feb.

Where I live, we haven't had a sustained unsettled spell since early last autumn.

The recurring theme of this season thus far has been predominantly dry, mostly settled and sometimes cold conditions dominating interrupted by brief unsettled spells, and the model output has IMO reflected this pretty well. It hasn't just been potential cold spells that the models have downgraded with time this winter thus far.

If a zonal flow is predominantly west-to-east, and a meridional one north/south, then you could argue that even 8 days out on the GFS we're still waiting for a zonal flow to establish itself.

Fair enough, it's zonal week on the GFS FI after that. But then again, it's always zonal week on the GFS FI.

There are hints across the models of the block holding well into next week. Tonights CMA is a case in point....
http://modeles.meteociel.fr/modeles/cma/runs/2017011912/cmanh-0-180.png?12

12z NAVGEM has moved significantly towards a stalled Atlantic and strong block to the east, as did the 06z parallel 

Indeed, it builds consistently on last night's 12z.  Meanwhile ECM in FI (day 6)

Hardly Zonal at this point.  You've got to admire the strength of the block.  First 24th, then 25th, now 26th for the SW gunk to arrive...

...edit...and when the rest of the UK shares in this week's frosts, watch the CET tumble a bit

http://www.meteociel.fr/modeles/ecmwf/runs/2017011912/ECH1-144.GIF?19-0

Interesting

http://www.meteociel.fr/modeles/ecmwf/runs/2017011912/ECH1-168.GIF?19-0

We have undercut!

Well into FI there but a disrupting trough...

If the trend continues, we could get an easterly but it needs to start showing in more of the ensembles.

http://www.meteociel.fr/modeles/ecmwf/runs/2017011912/ECM0-192.GIF?19-0

Close but no cigar but its not overly mild,

I'd love to see the postage stamps for the 144-192 range

SWly winds return on day 9.

More runs needed.

If the atlantic was as active just now as it was last winter, it would in all likelihood blow this HP aside with little difficulty. However, we don't have to look back too far to the last time the atlantic struggled to get a foothold across the UK at this time of year. I remember seeing an archive WZ chart for mid-Jan 2013 very recently, and the HP area to the east that produced that cold spell didn't appear to be that strong on the face of it.

That Atlantic low in the ECM tonight looks weird in the it has all these tiny little lows within the bigger parent low. Don't know why but the overall shape and spectacle of them reminds me of some weird alien shape that you would see in a 50's Sci-Fi flick or something

Even if this verifies, as long as the block is not too far away, it could come back soon

Yes.  I'm finding this winter the most fascinating model watching ever.  Its better than the hide behind the desk dread of the rainfest/storm fest of 13-14, for sure. 

Its a subtle battle for ascendancy between a jet that wants to loop and blocking highs that want to dominate. FI being around 120 its keeping us guessing and the zonaphiles must be chewing off their fists in frustration at the Atlantic not destroying the block to order.

A couple of cheeky outliers heading down towards the -10C line at the end of the GEFS 12Z.

Run 4 is a case in point...

'battle'? Bar three lows the weather has been amazingly anticyclonic for several months. There's no fight in the westerlies, its not so much a block as a 'stopped'. See the Arctic for why I suspect.

Zonal? I'm not a fan of relentless anything, but I would like to see some rain - the weather is just so inert atm - were this July the south west would be 1976ish brown.

Outlook? The models (as the seem to have for months too) indicate the weather might get a move on in the t+144+ range. We shall see...

Unusual synoptics -Not often that we see a winter cold front moving from  south to north across England .Southeast to north west yes but S heading due N rare I would think.