WxHerts

Well spotted..indeed was surprised to hear loud, heavy rain (and even the odd piece of smallish hail) outside here roughly 10 minutes ago - seemingly popped out of nowhere. Radar confirms that it was completely clear to my south at 21:20...it's now very dark overhead, there's a very distinct contrast to the relatively clear skies to my south. The night is still young perhaps..?

Best I’ve been able to salvage so far from my 19min vid of the London cell..

Hehehe am loving the view to my SW!!

Things look like they’re about to go down (or should I say ‘up’ hahaha how hilarious am I) to my N/NW..

Skies looking quite..fancy..to my east - few towers setting themselves up to my west as well.

Anyone know why UKMO 144h hasn't come out yet? Much better by d5 anyway..

ICON 18z, as well as having improved amplification due to WAA being even more vertical than earlier, is also further west than 12z with deep cold closer to us by d5...GFS will make for very interesting viewing if it shows the same - think we've latched onto something really significant today and who would've thought it just judging solely by the models 2/3 days ago?! Something tells me the coming spell could be more than transient too, let's hope the OP runs begin to toy with that scenario...if not though, how often do we get to say that cold weather looks set to start bang on cue with meteorological winter? Interesting times ahead

Probably not, short term differences most important to take note of at the moment though. A definite improvement by d5, hopefully GEFS reflect this and then ECM later

I agree that UKMO would likely be good if it were to continue on a few days. Compared to ICON and GFS at 144h however, it appears be the odd one out - UKMO flattest of the lot.

While UKMO appears to differ significantly to ICON, GFS at 120h looks very similar indeed...!

Very big differences between UKMO and ICON at 144h, UKMO lacking WAA.

Wow! ICON very, very different to earlier with cold and snow likely by d10 if the run were to continue. UKMO out in around 25mins, let's hope for more of the same

Beautiful start to the 12z runs from ICON, with ridge heading much further north whilst setup looks much less conducive for toppling. Now showing cold and frosty conditions by the end of November as opposed to chilly and drizzly on the 0z

Excellent day of model watching today, some beautiful runs and charts...however things are very far from resolved. What I've found most notable about today is the ECM's determination in keeping the unwanted Azores high at bay whilst allowing the doors to open up towards Greenland to take charge - very abnormal, however GFS says no to this scenario; though looking through to around d6, GFS differs significantly to UKMO, ICON and ECM. ICON 18z now out to d5, and while both runs are excellent for cold, there's still very big differences between the 12z and 18z (with 18z perhaps a slightly better route towards cold as it appears more open to undercutting) - to summarise many more twists and turns to come I'm sure, but there remains a massive amount to be pleased about as there has been over the last few weeks

Now now need to see be seeing far more runs than just this, however it’s true that yes, if this chart were to come off then we’d likely be heading into quite a prolonged cold spell - all looking very ominous to our north. It’s also true that there’s been significant model convergence this morning up to around d7 (bar GFS), seeing pressure being put in all the right places now

Fail to see what's so horrendous about the ECM this evening...?! Jet stream remains very meridonial and well south of its usual position, a raging PV is well away from Greenland whilst things continue to look very ominous north of Siberia, meanwhile significant amplification exits the states?! That on top of a significant stratospheric warming event being hinted at by the GFS 12z today I'm really struggling to see the negatives I must say.

ECM quite easy on the eye this evening...makes much less of high pressure to our east compared to other models as it makes much more of an effort to retrogress it over towards the Greenland area early on - PV looking quite ominous too as it lurks north of Siberia with some very cold air building...of course this is still all at/around day 10, though it must be acknowledged that other models definitely aren't a million miles off. Small changes earlier on will continue to screw up output later on so until the next 5 days are resolved and over with, there will continue to be massive flip flops from run to run in the extended range. Need to stay positive though as things really are not looking bad at all from a cold perspective...

Another excellent ECM at 240h, with a strong blocking high to our west whilst very cold air to our north begins a rapid descent south...parts of that chart are December 16th 2010 esque (a lot less extreme ofc)! Here’s to an excellent day of model watching

Roger that...ECM 12z features rapidly rising heights to the North round Greenland, along with strong hints of retrogression. Then finally the cherry on top is a strong low near the east coast of the US encouraging WAA and thus further strengthening heights to the North whilst also increasing the chances of an undercut later on. Meanwhile the Azores high is no where to be seen - always excellent news for coldies

240h is excellent.

People being too quick to react at the moment IMO, a few days of somewhat less good runs and it's all over...massive uncertainty at the moment so it's just interesting seeing what's being put out. The trend is our friend, and so is EC at 168h when compared what it was showing at this time yesterday - the differences are laughable.

UKMO good at d6 - would’ve been nice to see beyond. Need to see more of that circled amplification round the states which just isn’t there yet on other models..subtle changes such as that make all the difference.

Very good ECM, textbook undercut whilst heights continue to rise left right and centre..think we need to watch for sliding lows especially becoming more of a trend over the next couple of days.

D8 actually looks reasonably similar to GFS all round..infact low looks a bit more 'slidey' on ECM, let's see where this goes.

Evening all, first post on here but been a long time lurker..absolutely perfect setup at d10 on the GFS with Atlantic blocked off with unusually cold air (given time of year) fast approaching from the NE..this is possibly our first 'boom' OP of the season?! Interesting times indeed...