Duane S.

Quite agree. Little doubt we are heading into a more Atlantic sourced weather, just not convinced the ECM of the other day wasn't actually on to something, just much too early. It all looks a little half hearted, it won't take too much more of a southerly track/angle of the jetstream to swing things fairly quickly back in our favour. Watch this space, I get the feeling we may not have seen the end of that meandering weak, yet increasingly influential, wedge of heights over GL that the ECM was showing the other day.

A clear SSW now showing on this morning's Berlin charts. Better zonal profile below as well with that troublesome pocket of +20m/s speeds more dissipated. However, whilst the vortex at SSW level is clearly well under attack, it is holding firm (no doubt as a result of a strong W-QBO). Further up though it is a different story, it is in complete disarray There is little doubt in my mind this wont pass without consequence (in terms of further blocking and a cold feed out of the Arctic) felt on ground level come February. As per usual though, when where and in what form yet to be decided! I say 'further' blocking because in this winter of frustration and searching for snow events, it is easy to forget how blocked it has actually been. It has been a while since we've had so many frosts down here in a winter. Does make you wonder though what would have been if we'd have had the E-QBO that by rights should have been with us this winter...

Yep, GFS doing its usual trick. It never shifts massively from one run to the next when it's wrong. Just gradually, bit by bit, hoping like maybe nobody noticed.

Can't blame Matt for posting that, the ECM has been worse than ever this winter with over-amplification, and there is a fair old chance it is at it again but this isn't without substance. Maybe all a bit soon but I really think it is a lot nearer the mark than the GFS

I see Mr Murr has already posted (in more detail and better than I ever could) exactly what I was about to post about. The striking similarities between some of the background signals, Jan 2013 and the 'wedge'. All too often we look for record breaking bouts of Warm Air Advection shooting Northwards to the Pole to create a massive High Lattitude Block when a far more more innocuous weaker (looking) block with lower heights around the Iceland locale can really produce the goods. Sliders on a southerly tracking jet, once established i.e. are sliding south eastwards to our south west, can be winter game changers. The ingredients are there for trough disruption exactly where we want it. We have had rotten luck this winter, could February by a snowy month to remember??

GEFS starting to get a tad more interested in an undercut scenario as we go into Feb. I didn't view them all but the appetite is clearly there. #3 giving a classic set up... Gradual build-up of weak heights to our North aided and abetted by the Russian block and reinforced by the Eastern Siberian ridge. A couple of initial failed attempts and then et viola, the vortex eventually spins a daughter lobe off South Eastwards underneath us and hello snowy Easterly!

Very interesting ECM this morning. Vortex split of sorts, aided by Eastern Siberian ridge that sends a weak ridge over our side of the pole. May be enough to aid trough disruption, let's see if a trend emerges in the coming days of energy being sent SE through Europe as we go through Feb.

That is an eye popping top of Strat reversal now at D8 on this morning's Berlin charts... Further down, pole temps off the scale...

Northern Hemisphere shakeup coming into range. Huge upper Strat reversal depicted... Interesting times ahead.

Unusual looking u wind profile out in D10

That's weird. I ran through the Jan to Feb 91 cold spell evolution yesterday evening as I suspected it may contain similarities. It did indeed . Almost 26 years to the we day embarked on 3 odd weeks of a meandering UK / mid Lat high, until finally as we went into Feb we finally got one of the best cold spells in the past 30 years. These are not standard winter charts, I maintain we will be unlucky if we do not cop a sustained cold spell before winter end.

I agree. I think the fear (and it's not unjustified) from some though is this is the start of a trend to further 'downgrades' (I.e. further slipping south from the high). Unlikely, I think this is, give or take the odd blip, the 'worst' we are going to see the charts as we head into next week's continental feed of sorts. I do fancy the northern arm strength has been a bit over-egged in recent ops

You do realise that it only works one way though don't you?? :-) Seriously, I do get exactly what you are saying and would tend to concur. Easterly 'drift' over a period of time on the charts would appear to be far more prevalent than Westerly. Implying the models are indeed, on the whole, more prone to over-amplification than over-zonalification (sounds like a real word to me).

To be fair if I was viewing this 100's of miles further north than I currently am then I may well feel the same. The south has/had more insurance with this set-up. Still time for change, this may well end up being as southerly as it gets... You can't take away the fact the ECM nailed the pattern early on and didn't waiver.

Happy days. Easterly still very much on for many. ECM (as per normal) looks to have nailed the evolution. Looks (subject to change) drier and further south (the high) than we may have hoped for at one stage but that could change yet and there's what's follows next as well...

Putting aside will the Easterly (a PC airmass next week looks a fairly safe bet now) be dry or snowy (or more likely somewhere inbetween), the signs are all there for a 2 week UK cold spell. Could it be, for once, the timing falls in our favour!? One of those ultra rare times when im glad to be on the South Coast in an impending cold period (ref the Easterly). Thereafter the door is thrown bang wide open to Greenland heights. I suspect pictures of sausages could frequent this forum more than squirrels in the next week or so.

The easterly is still on. The form horse was always looking to be that Italy, Greece etc got the deeper cold (initially at least), with the South to be under an initial slack PC flow. The ops have re-inforced that. Reference the ECM... Very surprised we didn't end up with a better FI from that ridge thrown up on the +168. Albeit, I was surprised to see that strength of ridge in the first place following the +144!

Great 18z to round off a very positive day all in all. The GFS hardly ever does a dramatic flip / backtrack, more edging towards / baby steps.

I wish people would stop responding to the 1 or 2 same old boring posters who are seemingly desperate for spoilers, i ignored them for a reason. Anyway, a good ECM, probably a little more realistic with the high a bit further south. Never mind the details in FI though,which is totally pointless at this juncture, the main thing is, it has not backtracked towards the GFS.

OK, this is getting interesting. Good to see that, on the whole, the ECMWF is so far not drawing anybody in with its very tasty D9 / D10 charts. Treat with great suspicion until we see this in the much closer time frames. That said a perfectly plausible evolution just perhaps an outside bet at present. The MJO going into low amplitude phase5 however is going to have didly squat impact on whether this occurs or not. Berlin charts this morning (for yesterday) certainly shows that appetite for the Azores High to turn from foe to friend.. I was going to say I would favour a more Mid Lat block, drawing in a weaker and drier PC airmass than that on the EC FI charts but in reality it is actually more of a Mid Lat block than HLB anyway. So a lot of it will come down to orientation and fine details. If of course, and more importantly, it occurs!

Exactly my take. Had the cold spell in I.e. 09 not occurred we could have considered ourselves unlucky as so much was going for it. Others, perhaps Jan'87? you could say was very much against the odds. It all comes down to the drivers. Which are 'primary', when they are, which drivers drive which other drivers, under what circumstances and to what degree. Their interactions with each other are so impossibly complex that you very soon realise no computer will EVER EVER be able to get a handle on that. Chaos.

I still can't make my mind up If (and it's still a very BIG if) we end the winter without a notable cold spell. Should we should consider ourselves incredibly unlucky with the amount of non-zonal / blocking around the NH there has been or not be overly surprised considering the strength of the W-QBO and relative lack of tropospheric forcing on hand.

I see where Catacol and Tamara are coming from, entirely. There appears to be very little in the way of tropospheric forcing to encourage amplification (in the right areas) and ultimately a proper cold spell for us here in the UK. However, I can also see where Steve is coming from as the forecast Strat (tropospheric disconnect aside) wave2 activity could be the one single catalyst we are looking for. Maybe a bit simplistic but it is far from insignificant and at worst will put a serious squeeze on the vortex, at best split it straight down the middle later on. How the early winter cold spell got scuppered was a complete kick in the teeth as we were just damn unlucky. The dice are IMO not (currently) as loaded as back then but that doesn't stop us rolling a double six. There remains potential, I believe that potential will continue to grow, let's see if we can eek out every morsel of it going into and through the second half of Jan. And then there is still Feb followed by March, plenty of water left under this winter's bridge!

Another day, no change at all on the general theme. I'm still seeing this as a 3 shot (in terms of amplification waves) evolution. Shot 1, sets the scene (no great shakes, cold PM airflow), shot 2 (in view D9 / D10) close but no cigar (expect snow in the North, mainly on the hills but also at lower levels), shot3 (around 13-15 days time) our big chance to get some proper cold in and HLB forming somewhere above the UK. Outside chance shot 2 may prove enough but I think probably not at the moment.

GFS Looks good to me. Theme continuation. Details irrelevant. It will take 2 or 3 shots to get the cold in (hence mid month onwards being key here). Backing further west than the 06z