chris55

Block held to far east on the 06z for any meaningful cold to move in by day 7. Perfectly plausible solution.

If it verifies and delivers then i have no doubt we will

Whatever the inter run differences, you can not deny that is one impressive block! Every run different at the moment and the ensembles have no clear signal either. Very enjoyable period of model watching.

The cold uppers to the north east really do seem to get "sucked up" by that low at 144, although at 168 a second chance looks likely.

We will need to see all the data before making any judgements on the ECM, ensembles will be interesting to see where the op sits with regards to the cold pool positioning. It would be very nice to see the UKMO ens as well but unfortunately we don't get that info. GFS 12z ens data highlighted the uncertainty, we would hope ECM is on the milder side of its ens suit at day 7 re the cold pool.

Very good point Feb, this is one operational run at day 7+ If we take the ECM run as a comparison we can see the deep cold pool is nowhere to be seen at 144

Well those purple colours approaching from France are ....absolutely bloody freezing...we have not seen air that cold since 1987! If that chart was to verify then Paris would be looking at max daytime temps of -5/-8c or lower, and the south east is not far off, plus it is moving west towards the UK.

Nice to see ECM takes Fridays potential storm and Sundays potential storm south of the UK, firstly we avoid the potentially damaging winds, and secondly the further south the lows the better the longer term evolution with the block

Momentum gaining in the ensemble suite for a proper cold period! Just look at the those cold runs for the 8th-12th getting on for 10C below the average! Although no clear clustering so nothing set yet, far from it. London 12z

That's just what I was going to say Ali you would think there is a decent risk of some place seeing some heavy frontal snow from this upcoming set up, the battleground scenario is a strong option at some point

DeBlit ensembles in the freezer from day 7

ECM 240, make of it what you will

ECM 12z is a very realistic synoptic evolution, and with the UK climatology of recent years you would think the most plausible solution, however we are a long way off a certain forecast. And a slower route to cold ensues

IMO we have a higher chance of a cold easterly landing with the high centred to far north, rather than to far south (in the mid range) a sinking high has little chance of delivering meaningful corrections, whereas corrections west are slightly easier to achieve. Greece/Turkey nice and warm

Variations of a theme, until we get some consistency, no forecast at day 6/7 is certain

At 120 ECM has a nicely orientated strong high lat block to the east, where we go from here.....

Nick, surely the shortwave pattern will not be "nailed" until we get down to 72/96 at least and although we may get a taste at around 120, at 168 its open to serious fluctuations.

It's fascinating looking at how the ensemble line graph regarding 850s ties in with the Op from the 12z At face value the 850s look milder, but that (on the op at least) is due to the orientation of the block, rather than a raging Zonal flow incoming, small changes in the orientation could have quite significant influences on how the ensembles appear with temps at 850 850s line graph Orientation of the block is key to the warmer 850s And at day 7/8/9/10 and beyond the details of the block orientation will be open to change In summary, and very cliche, many many more runs needed!

This very strong Arctic/Sacndi high, at this latitude, will have the "clout" to deflect the incoming Atlantic, and to a point that will be regardless of whats happening directly to our west, a retrograde pattern would surely emerge, and one way or another we would end up with a flow from the east. Whether that includes some record breaking 850s or not the cold continental flow would be sufficient for any approaching fronts to produce some potential snowfalls. Just look at how the Atlantic onslaught gets crushed into submission by the building block. 120, block building, very cold uppers moving into Scandinavia 144, Atlantic lows doing there best to push east, but with the block and associated cold surface conditions, they are hitting a brick wall 164, what looked like a raging Atlantic at 144 with two strong lows, now shows one low retreating/disrupting against the block, in turn actually supporting the growth of the block!! its almost a self fulfilling prophesy! As long as we don't see the Atlantic "over the top" of the high then I think we are in for a continued period of colder conditions Obviously the eastward/westward correction of the pattern as a whole is very important, and corrections either way could have big differences on how the UK ends up being affected, but overall its not a bad place to be NWP wise as we head into Feb.

That's a cracking mean from ECM, best I have seen all winter.

Well GFS op doesnt make much of it, and sends it over France as a weak feature, however BBC forecasts highlighting the uncertainty of track and intensity so just keep an eye on bbc forecast.

I still can not get my head around this cold pool, it's spectacular!

Some crazy charts being churned out by the OPs! Look at that cold pool!

I agree with that, if the block verifies and doesn't sink, then we may just have to wait a little before the cold get sent towards our shores.

Its getting closer, so much to be decided yet, but for me the ECM up to 168 is pretty good, even if we have to wait for the northern arm to calm a little the building blocks are there for sure