ITSY

Hmmm. Two GFS OP runs in a row...MOGREPs trending colder...UKMO looking favourable as we lead into medium term...hate to use the *potential* word but that's what this Xmas period is screaming to me. And how nice to type that with 3-4 inches of snow in the back yard... EDIT: The particularities of this run don't end quite so marvellously - we need lower heights to swing into Europe as Nick Sussex and others have already commented. That will help advect the cold west and south. But at the lower resolution range, what we're looking for is TRENDS. And the trend from the aforementioned models is positive... 06Z: Split PV N-S 00Z: Split PV N-S

really amazing scenes in Hampstead this morning. 8-10cms of level snow on cars this morning, albeit now thawed by traffic. 10-12cms widely on gardens with most of the Heath at 15cms. Easily my heaviest fall since March 2013 in Cambridge - almost 10 years ago.

Not been outside yet as struck down with a severe cold but there’s probably 5-7cms level snow here in Hampstead - far more likely on the Heath. Thought we’d be too far NW for this kind of snowfall but very satisfied. Heaviest fall for me in either here or Cambridge since 2018!

The 'all routes lead to cold' scenario plays out nicely on the ECM, with it getting a north atlantic block in place by Day 8, even if going about it in a roundabout and unfavourable way from our POV. Patience, grasshoppers!

It is worth noting the Para, just for wont of other examples this evening. It is not having the evolution and going as per CS's comment above. Out on its own for now but one to watch as ECM evolves

I'm not sure I've ever seen such an extensive area of blocking, as the GEM is now showing for +198

For goodness sake, I'm now remembering why I've not been in here for the best part of 6 months. You can't expect scenarios at T+300 to jump to T+192 without time. Allow the evolution to develop. I kind of wish there were a function that would prevent us all from posting until operational runs were finished! As I said earlier - patience is a virtue in this game. Anyway, the setup is perfectly poised for a cold incursion on that run from the GFS Op. Eyes towards the Para, the GEFS and then the GEM and ECM to see what they've got in store.

Icon is a move in the right direction. For those newbies watching and participating in this early season fun, I'd say that essentially anything within the next week and slightly beyond should be looked at as building blocks, getting the pieces of the puzzle into place...

First foray into the season for me - work & football have kept me at arms length but it's now too interesting to stay quiet. I don't have much to add beyond the general optimism that's been shared. That being said, us seasoned folk know that if there's a way for it to go wrong it will so we need to keep grounded. There seem to be two challenges to look out for as this pattern develops - first is the uppers once the cold is established (and as others have said, getting the cold pattern in place is what is most important in the short term), the second is ensuring the emerging Azores low signal doesn't drag the medium term pattern into a west-based -NAO. That's hit us hard a few times I recall. My instinct is that if this materialises the first 'wave' will be a relatively benign Easterly-type event that pegs back temperatures a bit towards or just below average (and will annoy people in here), but which sets up a broader pattern that is much more conducive to prolonged cold and snowy weather. As always, patience is a virtue in this game. Luckily for you guys, I'm off to Israel or a week at the start of December which, knowing my weather luck, will probably seal the deal for you all!

As per one of the 00z GEFS earlier on with a 41c forecast over Suffolk on 4th August…

UKV sneaks out a 43c on Tuesday, somewhere over Leeds. Barely fathomable.

GEFS P13 is a furnace. 40-42c widespread across England. Wild

And the MOGREPs ens- on the last page - show most runs with 20-25 850s over London.

I’ve had 42/43C once in the Israeli Red Sea resort of Eilat, which borders the Sinai desert, Negev desert and Arabian desert, overlooking Jordan and Saudi Arabia. It was barely 10% humidity and like walking in a hairdryer. Every building, even markets, was kitted out with incredible aircon - non of that exists here. To experience it in England would be nothing short of insane.

We've got used to some mind-bending charts but the idea that Cambridge would ever be modelled at 44C is insane.

Here we go again. 40 for the south, and at 8pm too.

It really isn't is it! It's not as good as before but it's not what I was expecting either - the High is further to the NW than I thought would be the case (think UKMO) and the prospect for an undercut isn't out of the equation. It won't be the bonanza of earlier but I'll be interested to see the GEFS and ECMWF later.

The differences at short range a huge, even between UKMO, ICON and GFS at +100. I think this run will be less amplified around Iceland judging by the position of the Low in the mid/n Atlantic and orientation of the secondary low in Northern Canada.

That would be a historic event for the SE quadrant, the way the low intensifies and stalls on its exit northward from the channel. I doubt we'll ever see such a scenario - not just in this winter but in a generation - but it's quite amazing to look at what's possible. The snow is actually intensifying here in the final frame so you can add another 5-10cms minimum for the whole area before the event subsides. 15-25cms widely to low levels from that, Chilterns 30cms+. Nice to look at! Back to reality, the GEFS are really not that great in the medium-long term. We need to see the PV continue to shift to our side of the Pole and then watch for openings for a favourably positioned MLB.

"We're back to chasing 10 day charts again" - I'm sorry but are you trying to mislead people with this? It's like listening to the Kelly Anne-Conway "Alternative Facts" speech. We're not chasing 10 day charts again or anything like it. A substantial portion of GEFS, EPS, MOGREPS, GEM and others show snow to low levels midlands north this weekend, 5 or 6 days from now. Just because it doesn't snow in one corner of our Island doesn't, I'm afraid, mean that we're back to 10 day hunting. Statements like those sow confusion and are not helpful. For the uninitiated, we're looking at several possibilities here: A cold but dry xmas and Boxing Day as the low filters too far to the south, with cold air filling the void (for how long we don't yet know). This is projected by a substantial % of EPS and MOGREPs. A snowy xmas for midlands northwards, particularly but not exclusively on the hills, as the low pressure system takes a more northerly route through southern england, dragging colder uppers down the spine of the country as it leaves the UK through boxing day, enabling Easterlies take hold. Whether that's a harsh wind or a benign one, and whether it lasts for a day or a week, is yet to be determined. There is no consensus on day 4 right now let alone day 7 and beyond. A snowy xmas night and boxing day for central-southern england if the low tracks just right across the English channel All of this, as Met4Cast has previously stated, is dependent on the resilience and shape of the 'Griceland' block in the first instance, which influences the route and exit pattern of the low pressure in the second instance, and then the advection of high pressure over the western portion of the British Isles in the third instance. If this advection moves right we could set up shop for a cold and blocked new year. Or we could end up with a Bartlett, a UK High or anything else for that matter. Projecting this far out is frankly ridiculous. In short: there is much to be interested in for the short, medium and long term over different parts of the country. Everything could yet go mild or go cold. We don't know. That's the beauty of predicting the weather...

Indeed! Let's see if that catches on. Maybe the prolonged phase 7 MJO forecast catching up with the models? Who knows. The ECM and UKMO will be instructive overnight. But for now, some really exciting trends on the GEFS suite (albeit a heavy jar with the ECM EPS suite earlier this afternoon): Cambridge Newcastle Midlands South coast

Well. Quite an impressive medium term picture emerging on this suite: Control: P1 P2 P5 P6 P9 P10 Haven't been through the rest but it's a telling picture of what *could* materialise if things fall correctly...

The pace of this thread is so fast and split-personality at times that things get lost in translation. The "hype" in here is about the potential setup for most of the country after X-mas, starting with Boxing day and going into the weekend. If you're in Scotland, resident atop a Welsh mountain or living on a central-northern English hill somewhere, you might still get lucky before hand.

So to sum up: the ECM has made a short-term move towards the GFS/UKMO solution but without fully towing in behind just yet, particularly when it comes to the depth of cold. That's a start for me - the GEM is pretty close to the GFS/UKMO solution too so I'll take that given that this time yesterday it looked for the world like we were heading in the other direction. 18Z for a refresh and then a behind-the-sofa glance at the midnight runs tomorrow morning. For now, positive steps towards a cold spell over xmas weekend. But it could still swing back the other way... Quick Edit: White xmas chances, as I said this morning, look increasingly possible for northernmost and hiller residents further south into the Midlands. But it's what happens afterwards that is now the centre of attention.

I've got to say, I've been on these forums since 2008 and I've never seen such a confused short-medium term outlook. One minute it's Easterlies, then it's Bartletts, then it's winter cyclones. It's exhausting actually and a real nightmare for forecasters. It would take something pretty remarkable for the GFS to outperform the ECM and UKMO at short-range but only yesterday it was the other way around, which is what makes me think that a) it's possible and b) stranger things have happened. We're having our 2nd Pandemic xmas in a row, the Liberals just won North Shropshire and The Donald was President for heaven sake. Truly, these are weird times. And in weather terms we have Pacific typhoons, a stronger-than-expected La Nina, an MJO that can't make up it's mind what to do next and a gradually weakening SPV all playing havoc with medium-long term winter forecasts. That's (just partly) why the models are so chaotic. It's a highly unusual setup, locally and globally, short and medium term. I think the thing to remember here - and the thing on our side - is that this is still the first month of winter. If it doesn't work out it's not the usual ball-ache of knowing that's it for another 10 months. There's plenty of water (and icebergs) still to flow under the bridge. And most of all - this is a hobby isn't it? If people could resist the urge to act like internet trolls or toddlers in the playground, that will help people to learn. Having observed this thread from the side-lines over the last couple of days, I do wonder the merits of not allowing people to post until runs are finished. It's so tedious to see "what a Boom run" followed by "another total disaster" seconds apart. That might just be me though. Anyway, enjoy the drama folks. I'd say the form horse is late xmas snow for the north and higher ground only at this point (an ECM solution that blends slightly towards GFS) but with a very real possibility of a more southerly boundary emerging over Boxing Day and beyond (the GFS solution today and UKMO solution from yesterday morning). From there, whether it's a 2 day affair or a week-long transition to something even colder remains to be seen. I'll certainly be looking at the Strat for the first two thirds of January.