kold weather

We are certainly moving closer to a very interesting set-up now, both short term and long term. Short term prospects for snow continue to improve, it is mega marginal so any altitude and time of day will make a big difference to any snow chances. Given the LP has dropped further south it has relaly increased the chances. Remember if your on the left side when its moving north and right side when coming back south that will be the zone where the snow action will be. At the moment a little too early to zero on where that might be and could still easily downgrade again, but at the moment looking interesting for an early season marginal event. Longer term is also still looking interesting, blocking very much theme of the day, even if we do get a small spell of flatter weather near the mid month. I'm feeling increasingly confident that the week before Xmas will give a decent cold shot, its just from what direction it comes from. The one thing that is obvious now is we are staying away from mild for the time being and a below average month looking increasingly possible, even probable. @BLAST FROM THE PAST we are moving closer to that superb outlook now!

Moving ever closer towards a marginal snow event late this week. We need to watch the left hand side of any LP that forms as that will bve where the cold air will orginally tuck into the developing low. If the LP does then eventually swing back the threat will then move towards the tigh hand side of the low. Surprising amount of models are showing snow at least for some of the time on Thursday/Friday, especially further north. Whilst it is likely to be marginal, and high ground will be of real benefit, its close enough to warrant a close eye, even a slight upgrade will increase the risks significantly. Longer term things still look really interesting, still precious little hints off mild air. Still some uncertainty though just how much deep cold air can get pushed down towards Europe, but with such a sustained period of below average temperatures we increasingly will be less reliant on deep cold to do the job, especially in set-ups where we pull air off Europe.

Also just looking at the extended ensembles from yesterday 00z and they were pretty outrageous overall, many runs have at least one decent blast of cold air and quite a few delivering the goods over Xmas, a few channel lows thrown in. Normally I'd not pay too much attention however given we have already seen a tendency for diving LP's at the moment, I'd not rule out that pattern repeating with more favorable cold around. For example: Which goes from a long sustained snow event for the south of the UK and then morphs into a decent easterly. The covid Xmas plans may be in trouble due to snowfall if some of these runs start to be firmed up on in the near future... Some more cold excitment: Can't go wrong with an occasional ramp right!

Still look like a case of nearly but not quite on alot of the latest runs, but really wouldn't need too much of an upgrade to swing us almost over the top to some snow possibilities. We continue to also look like having a sustained period of below average temperatures, little sign of anything other than below average for the next 15 days. nothing too cold but the surface will cool nicely over that time period and that will hopefully put us in a good position for the rest of the winter providing we do get another chance and it doesn't morph into a la nina shocker - no indication yet of that happening though. Just gotta keep our eyes on what may well be coming down the line...

I think this spell coming up in and of itself is going to lead to little in the way of snow chances apart from maybe on higher ground. Its a classic "if only it happened a few weeks later/earlier" type pattern and insanely marginal. Most may get rainy sleety mess and perhaps a few flakes at the back end of any heavy showers/cold fronts. However rather than viewing this as the whole dinner, perhaps it would be wiser to view this as the starter course, the thing that helps to cool down Europe/SSTs from being very much above average towards something we can benefit from if we get a reload a few weeks down the line from what is being seen on the models at the moment. I'd be very surprised if we don't get at least one more bite of the cherry between the 15-30th December based on how persistent that diving LP set-up is becoming on the models. Also each day that passes and we stay under a below average set-up across Europe helps to sway us towards less marignal situations IF we can get any future slidders/divers. Often cold winters have these sorts of cold primers at some point either in November or early December. So whilst it may feel like we are wasting this set-up, I'd be somewhat positive that this won't be our only attempt at cold. I know some people are still carrying battle scars from the last 2 winters and are desperate for a set-up to come off, but those of us who have been around a long time know sometimes you have to do the ground work first.

This is very true, my only concern is as Singularity said, the SSTs are higher than I'd like to see and whilst definitely cooling down, I'm not convinced that Europes surface profile is quite cold enough with a total lack of deep cold anywhere nearby. It'd extraordinarily marginal in many of the set-ups being suggested by the models. Perhaps a classic "on high ground" with an awful sleety mess lower down even in a slider situation unless we see a slightly more impressive cold signal developing at the surface over the next 5-10 days (given how close it might be, I'd not rule it out). I am however increasingly interested in what maybe coming down the line. If we can keep seeing these upper lows trying to drive SE/S into Europe its only a matter of time before we get a stronger mid atlantic ridge and push down some much cold uppers. Once that happens we could quite easily get trapped for a 7-10 day period with cold NE/E type airflow that wouldn't be marginal. It might mean a 5-7 day period where things flatten, but unlike most winters where I'd be thinking that is the end of things, its clear the vortex is going to be under pressure and that leads to a good chance at getting a proper injection of cold into N/W Europe.

Well its the hope that keeps you going I suppose! Very solid 18z GFS op run. We would be looking at a decent length cold spell should that come off. It collapses fairly quickly but I'd suspect you'd probably get a repeat episode a little deeper into December, especially there is some decent long term support for that. A long old way to go yet mind you and the last few years haven't exactly been great for these sorts of things.

Whilst 12z runs are rolling out looking at the extended GFS ensembles there is a signal that after perhaps a slightly flatter period things start to amplify again as we head past mid month. Quite a few cold Xmas runs, bit of course this far out extreme amount of salt required.

The 18z GFS ends trying to move a lobe back to where we absolutely don't want it to go under all circumstances...unless you want another Dec 88 or 89....

Yeah there has been some discussion from a few on here today earlier that if you can get a strong enough upper high developing it will help to disrupt any developing PV. Anything that can keep the PV from coupling up through the atmosphere is a good thing obviously. The 18z looks a little flat for my liking though, and its rather different quite a few of the ensembles from both the EC and GFS that are trying to keep it at least somewhat amplified, even if it isn't necessarily to our benefit always.

Decently cold at the surface towards the end of this week, probably getting maxes around 3-5c, so pretty cold for the time of year. With that being said, I still think anything more than a few flakes in the air mixed in with rain is optimistic based on what I can see with regards to this flow, unless of course we see something of an upgrade (very possible). My main attention is still further out beyond day 10 when we can hopefully finally get some upper cold loaded around any upper high that develops to our north, IF it develops of course!

Its another one of those 'shower' mind you. It looks synoptically fantastic, then look at the actual flow and its a little bit, well, meh temperature wise. The big problem with alot of the set-ups we are seeing, and I will keep banging on about this, is we just don't have any decent level of cold across Europe. Thats not to say it won't get colder than normal, it will. However without a strong surface cold pool to draw upon any sliders are going to high a high chance of introducing air just that little bit too warm. Given we are in early December the uppers don't look quite there from any easterly flow either (-5c with SST's above average in early December won't cut it for much in the way of snow from the north sea) Of course the thing I will say is keep getting LPs sliding across is no bad thing and we may get there anyway in the end, I just would prefer getting even a short lived northerly first, or a strong undercut Scandi high type situation to pull air in from the far NE. At the moment the diving LP's are just circulating recycled Atlantic air via Europe, and its simply IMO not quite at the level of cold we really need to make things properly interesting... Yet...

Seriously the evolution is just pure filth! Its almost as good as it gets in terms of the upper high over Scandinavia and into much of the Eurasian portion of the Arctic. Whilst I doubt we go anywhere near that extreme, there is some tendencies already being seen towards the Azores high trying to ridge up and over the top towards Scandinavia. With a bit of luck we will get one in the near future that has some decent deep cold to tap into. This combined with more than a few hints that the zonal wind speeds are due to drop, perhaps markedly, and its perhaps not a totally outlandish prospect down the line.

12z GFS is more Atlantic based as Steve said earlier on, probably less cold at the surface but colder aloft, probably a higher chance of there being snow around but most of it confined to higher ground. Still a fairly cold run overall, though perhaps a little less so than the 06z due to the Atlantic influence upto day 10. Precious little deep cold throughout Europe, though the synoptics don't look too bad on this run. We'll probably drag in a fairly anemic easterly flow beyond day 10. Could evolve into something more tasty day 15+.

Also worth noting the GFS 00z extended ensembles are also starting to show more ridging occuring with decent attempts at building HP towards Greenland from the Azores in quite a few of them, to varying degrees of success. Given all that, it is indeed something to keep an eye out for. About time we got some luck given recent winters.

If it turns into the building blocks then yes, it will be fine. If this IS it, than thats a whole different story again. I suppose my main point of view is though I don't see much realistic chance of snow from this run, I don't see any really deep cold, the surface flow is somewhat cold but is that really enough to label it as superb? Of course the pattern could shift subtly to become more interesting in future runs, but I'd feel far happier with any a modestly decent upper cold pool in Europe. Without that I fear any air we import will be cold, not cold enough type job. Seasonal maybe the best way to describe it, without any real prospects of snow in the medium term. Lets hope for upgrades! PS - its a heck of a lot better than last year though, and we keep a decent period of below average temperatures with on real sign of any milder intrusions at the surface, so I'm hoping I;m not coming across too negative with it! I'm just a bit snow starved from last few winters!

Without going off topic the problem is we are at far greater risk from marginality than most though ,especially north of 50N due to the gulf stream, etc. So 1-2c increase won't make too much difference to snowfall marginality for N.Norway but will increase snowfall, but for the UK that can make the difference between rain and snow as we've seen before. Anyway I'd struggle to call this run superb...its barely even in the good category for me. Probably a slim chance of snizzle from the east at day-10 but as it is, nothing too interesting. If this is superb then our standards really have taken a drastic fall due to recent years my word! Edit - lets reminds us of what superb looks like, control GFS 00z extended: Thats the hallmark of greatness!

The other thing I should mention is also we'd be mighty unlucky to evolve back into a mild atlantic pattern if we can keep getting these LP's forced southwards. Its a much better pattern than we've seen in quite a few recent winters, even if I'm personally less than enthused because we are depending on very marginal homebrew surface cold pools over Europe. Cool/cold with probably quite a lot of cloud cover. Those that can escape the cloud should see frosts. Surface flow will be colder than 850hpa temps would suggest, and its a pattern that could well lead to a decent CET for December should it hold for any period of time....but that will be all for nothing if we see the typical La Nina pattern kick in globally through December, or if the vortex suddenly couples. I dare say we are trying to play the long game whilst very much on the timer, will we run out before we get the real good stuff?

We are always going to be struggling for any noteworthy cold in a pattern seen in the GFS/ECM. Its a pattern that can look amazing but it really is lacking in any meaningful cold throghout a large chunk of Europe due to how it evolves. Because of that you could get cold looking synoptic pattern with good HP development to our north/LP in Europe and be funneling only a modestly cold surface flow - but not anywhere near the levels needed for snow. Really need to ensure the LP to our NW gets far enough east in the first place that we can end up being on the western side once the LP dives southwards, or further west (closer to the 00z GEM) so we can at least keep the original ESE feed for longer which whilst not exactly bitter, does keep the surface colder. Overall I'm struggling to get all that ramped about this set-up, its a fairly bog standard looking cooler spell with some frost around if cloud cover allows. If we had any semblance of stronger surface cold than present, it would be far more interesting but its very lukewarm for W.Eurorpe on that front. somewhat better perhaps over C.Europe but still no great shakes. In conclusion, its a pattern that synoptically looks decent enough but will underperform temperatures wise I suspect. Below average for sure, but nothing that makes me think "get in there". It *may* evolve into a more interesting pattern down the line hopefully but that could still be some way of.

If somewhat cold rain gets you excited, then this is the chart for you! If only those were surface temperatures!

Same basic page as yesterday with several varying options down the line, the ECM still quite keen to shove a strong LP southwards towards Spain which probably ruins otherwise decent synoptics. Only way to cold from that evolution is a near complete reshift in the pattern which obviously holds real risks as well. The GFS has less risk of that but in itself isn't all that interesting. I think there is merit in the idea of some form of ridging trying to establish in the Atlantic which we are seeing in the GFS and to a lesser (and more westerly extent) on the ECM. However, it does seem like we are in for a reasonably cool period, some days will probably be outright cold at the surface. How frosty it is probably depends on cloud cover, I suspect for the SE quarter there will be less chance of that than further NW. So cool, maybe cold for some. Very little hope of snow other than maybe the odd bit of snizzle perhaps. Going forward little sign of mild, but also not much of a signal for anything too cold or snowy either.

Looking at the ECM ensembles members individually there is a somewhat stronger agreement tonight of keeping HP more in charge than it is on the GFS, especially over Scandinavian regions, and instead the LP is forced southwards/SSW. I'm guessing that is also starting to show on those NAO forecasts as well from the ECM det. It means we end up pulling in either a very lukewarm easterly (not cold enough for much given above normal SSTs and above normal soil temps) or a SSe airflow. Both would probably be below average still but we'd need to see a somewhat different type of pattern to get anything meaningful in terms of cold/snow potential if that were right. Cool more than outright cold probably in those solution It could also mean in theory we end up with cracking northerly blocking and still keep a somewhat poor outlook dominated by the southern flow of a LP to our SW. There are some northerly airflows in the mix as well, but they are not what the 12z ECM ensembles favoured. Plenty of time for both up and down grades at the moment, and lets hope models continue to strengthen the easterly flow into something that could be useful in the medium term. Very subtle long term hints from both ECM/GFS ensembles that the atlantic northern arm of the jet re-strengthens towards the very end of the runs. Nothing to yet be worried about, but when both sets of ensembles pick up that signal even that range its worth keeping an eye on. Also worth remembering, that doesn't necessarily mean a rampant Atlantic either, especially if we have the right blocking pieces in play.

So there is definately a path towards sustained cold on the models but its a really messy path, we could just as easily see the LP sink SSW and us end up in a southerly airflow followed by a toppled HP that morphs back to a Euro High. There seems to be a theme on the models for LP to move SSE close to the UK past day 8. Its a pattern that will make it very tricky for any milder air to try and come in at least at the surface, however its also a pattern that will take some time to bring in much colder air unless we get a lucky break with the positioning of everything, and lets be honest, when was the last time that happened! If you want to see a version of that, look at Ptb.5 on the GFS ensembles, an utter monster of a cold run. In the shorter term, we have got a cool, possibly frosty outlook depending on cloud cover (but either way suppressed surface temps) with maybe a chance of something trying to sneak in from the east briefly?

Cold brief northerly with a reloading pattern from the NW possible. The GFS is probably underdoing those 850 temps a little, given its well known cold bias at those ranges by it's still a decent enough quick shot down. Certainly cold enough for s ow showers. Overall it's a cooler outlook, but other than a brief northerly nothing too cold nor sustained. Snow opportunity for the usual suspects in toppler northerly, elsewhere probably cold and frosty if the GFS came off.

At least in terms of synoptics upto 240hrs the GEM 12z actually looks pretty similar to the 12z GFS with how the low pressure evolves to our west. Any major frost on the easterly flow would probably be cloud depending, but at least you'd get surpressed daytime temps, and if cloud isn't much of an issue, then frost would be likely.