Stu_London

for 240 hour verification, I would say that is about as good as it gets in wintertime

I think the models handled the current situation really well. There was always going to be some variation in exact positioning of the low and associated troughs and fronts, but on the whole it was pretty consistent in showing a below average period of temperatures following a vigorous storm with some prone spots getting some snow. Some of the expectations of the forum community were a little elevated, especially to start with, but that is understandable given the relative rarity of these types of weather patterns

Sleet in Tunbridge Wells - an improvement on last nights rain!

Last few GFS runs have been consistent in pausing the cold spell around the 220 mark. Better run for 06z as it gets colder surface and upper temps established in the areas that could provide a reload further down the line. Hopefully the trend continues.

Problem at the moment is the origin - some of that PV from the other side of the world moving over as per the control run would get a few really cold ensemble members in play. I have to say, agree with Jason M on the amazing hemispheric pressure patterns, yet very poor temperature profiles. Even in the worst zonal mild winters there are a few crazy ensembles, that never get near verifying, that go off on one and hit below minus 15C - not seeing any of that this year. Suspect it is due to the deep cold being too far away - SSW might shake things up a bit

Rain shower here but there is a slightly heavier burst on the way - so that might be more promising

there was a suggestion of some wintry ppn around the London area tomorrow morning on the BBC Countrywide forecast. Not that they are particularly accurate - but I think maybe 40-50 miles east of your ppn extent line is possible.

Given that even though it is the dead of night now and we had a frost earlier and it is now raining where I am - it will probably be rain

raining in Tunbridge Wells - which is slightly disappointing as it kind of felt cold enough for at least a bit of sleetiness

I think the first most knew about it was about 3-4 days before on the Sunday countryfile forecast when John Kettley flagged up the coldest spell of weather for around 4 years (presumably referencing Jan 1987). Computerised models were around then but not in the public domain. Met office and sensible media (i.e not the Daily Express) haven't changed their habits much in 30 years - still like to sit on the fence until around 3-5 days from any event, which says a lot about where FI starts.

Apart from the -5 daytime temps, -16C uppers and 1050mb Scandi High, I would say it is pretty much an exact match

Fully expect this to get moved to the moaning thread but it isn't a moan, it is a realistic appraisal of the model output as I see it. This thread is a great read and the models are positively eye candy compared to the last couple of years, however lets not forget. the best charts have always been and remain just out of the realistic time frame at +120 onwards. there remains anomalous warmth over much of Europe. Very few cold spells that only affect the far west of the continent are severe or have any sort of longevity. the 850s are still an issue. Temps over much of the country will easily get above freezing on most days meaning any ppn will be marginal and if we do get any settling snow, it will likely rapidly thaw. it has been a mild and wet December - there is latent heat in the soil meaning snow might not settle or will thaw from the ground up if it does settle. To my mind, a severe winter spells mean lying snow for several days and temps struggling to get above freezing. Whilst there are some encouraging building blocks in place for this to happen at some point, I would suggest to newbies reading the forum to enjoy the banter, but divide what is actually being predicted by about 10.

Not every easterly is a beast however. Longevity, uppers, size and shape of high all are factors. 1986, 1991 and 2018, the only true beasts in the last 35 years, in my opinion.

and just watch the scatter for the long ensembles - some might go over +5 - others might be close to -15

Id say a beast would be defined as a big scandi high and a trough dropping out of the arctic around it's southern flank. Not quite there - yet.

GFS blows up the LP to the south from 225hr which is a bit of a spoiler for the rest of the run, but excellent run for cold up to then. Remember how tight the long ensembles were a few days ago - well they are going to be all over the place for the next few runs with a spread of 20C of more on uppers and there will be some frigid ones in there. Classic vortex destruction signal

I would say you are guessing right. But you never know, its a very fluid situation. London tends to fare better with winds in the easterly quadrant, so perhaps one or two surprises a bit further down the line.

Sleety mess for most in the south east. Downs might get a covering

winds really picking up here in RTW. Severe drizzle atm. Stronger winds expected over the next 6-10 hours. Not seriously expecting any wintriness before the new year now.

Not sure the GEM has ever verified at that range - but nice charts to look at.

Remember this one quite well. I lived in Enfield at the time. Lots of snow falling out of the sky but not much settled. Ruislip, around 10 miles away, and with a tiny bit more elevation, got pasted with about 5 inches and there was complete carnage on the Central Line - many colleagues had real difficulties getting home from work. Think we will see similar in next few days given the marginality, local prone areas hitting the jackpot, with other areas quite near missing out.

Rain for me, down here in Royal Tunbridge Wells

compared to recent output - the long term prospects for cold on the 06z is pants. luckily only one run and in FI - hopefully not the start of a trend. My concern with these forecasting models is whilst they often overstate the cold, when it comes to the mild, they are usually eerily accurate.

been a struggle to get any cold air in Europe this autumn to be fair

Hi Chio As I sure you will agree standard fayre when a SSW is in the offing. Would expect the GFS long ensembles which of late have been as tight as I have ever seen them, to go completely haywire with huge spreads in the next few days. In the meantime, whilst I don't buy a significant snow event between Christmas and New Year (unless there are some unexpected upgrades), the period just after is looking very interesting and a disruptive snow event might be in the offing early in the new year, even before the strat effects well down.