Mucka

GFS very precarious but they can be the best setups for a good dumping UKMO more solid and would likely bring snow further S

GEM is worse case scenario with the Iceland low blowing up to the N of the UK, hopefully very progressive with the phasing.

So long as the Atlantic pattern remains amplified we will get our cold snow eventually and GFS still seeing the next wave around Dec 2ns as I mentioned a few days ago. There are far too many permutations to have any confidence in any given outcome for the UK early Dec but we can be fairly confident there will be high lat blocking and cold air around to tap into and it almost certainly won't remain dry.

Yes, we don't know how things will pan out of course, but with such a complex setup the actual weather for the UK could vary wildly run to run and there will be some very snowy runs in there and some wet and windy ones probably. Overall 850 temps look like they will marginal over the mid term adding to the drama, These shortwaves and cut off lows don't get anywhere near modelled well until we get inside T120 and then the models start figuring them out run by run. Should be a fun few days, hopefully not too frrustrating.

Consequence of being surrounded by relatively warm waters I'm afraid. We nearly always have shortwave drama don't we?

We have certainly trended toward the more precarious but exciting scenario with low pressure and cold air in the mix around the UK for end of Nov start of Dec Could be snowy or tears at this stage but with blocking still in place we may eventually get some colder air over us in Dec, assuming it doesn't all go TU.

The low SW of Greenland is being modelled stronger and stronger and the ridge getting thinner and thinner and being pushed further E as a consequence. Now & then Nov 27th Need it to hold on until the cavalry arrives with another ridge.

Seems unlikely with +4 860 temps for much of the S though GFS snow chart not bad either away from far S Not that these mean anything right now.

Very snowy start to Dec from GFS Op this morning and GEM not far behind though has warmer uppers into the S However the snow comes from the Iceland shortwave as it drops S and phases with another shortwave to the SW and the Euro trough to the E and timing is everything so unlikely such a perfect setup will be repeated unfortunately However a glass half full outlook might be that this run shows the potential for widespread snow from that shortwave next week. UKMO also phases the Icelandic and Atlantic shortwave but further W and it blows up the low into a storm. I would say that is maybe even less likely than the GFS scenario but if it happened a little further S and E then it would be a snowstorm instead of rain. Overall though these Op runs are to be taken with a truckload of salt as the shortwave dramas are likely to continue to change the output and the changes in outcomes for the UK could be quite dramatic run to run.

As far as I can figure, the only way the shortwave low around Iceland 144/168 would be a spoiler is if it blew up to the W or N of the UK. That would be rotten luck but the UKMO does sniff at that option. Otherwise it would just be a temporary cut off a cold feed. Other than being a spoiler though it might actually help sharpen up the Atlantic ridge behind and blocking into Greenland and if it travelled E of the UK it could bring widespread snow and sharpen an Easterly feed. It would be safer for it to be phased out early as with GFS 144 But I can definitely see how it could be as much a help as a hindrance if it does develop more in line with ECM. Definitely something to watch for in the overall pattern as it develops post 144, (foolishly assuming we now have out 120 nailed )

GFS has always been strong in that N/NW (SW Greenland and Iceland sector) in picking shortwave activity for some reason, not sure if it is a data thing for the Euros but UKMO comes good there once inside T96. Odd idiosyncrasies each model has that we pick up on over the years of trawling thousands and thousands of charts.

Ah, I presumed it was ECM output, you are right of course. But that ECM chart does show potential for a marginal snow event for E/SE England and high ground as cold air mixes in

What a difference a day makes It is mazing how finely balance blocking patterns almost always are that can bring cold to our shores.

Definitely for important detail early next week, but all the models now have it following the GFS in pushing it through and phasing with Sceuro trough which sets up the high lat blocking pattern. A backtrack now after the models finding consensus would be brutal.

A possibility I mentioned earlier if the pattern moves W. That shortwave mixes in with some cold air as it crosses with snow to high ground and perhaps some E/SE parts of England.

Big difference with how ECM is handling the shortwave, now like GFS, as opposed to its output yesterday and much better Atlantic ridge as a consequence.

So UKMO, Icon, GEM now all pretty much on board with the overall GFS progression out to 144, ECM odd one out but moved a little toward GFS this morning like UKMO.

Pushes the shortwave through like GFS which has really led the way so far. It is still isn't fully locking in the Euro trough like GFS so let's hope GFS is right on that as well.

It is asking a lot but if GFS is right with the track of this shortwave across the UK then a few corrections West of the Sceuro trough and widespread snow could be possible early next week. Long shot for sure, but worth a look.

GFS mean Nov 30th

GFS keeping the upgrades coming this morning. Up the garden path or to the promised land? UKMO has probably made a small step toward GFS this morning, re shortwave, out to day 5 before going pear shaped GEM looks pretty good out to 120 as well but also has the wheels fall off later. So I would expect a much improved ECM this morning so far as blocking pattern goes. GFS has done pretty well with this amplified pattern and looks like it is leading the way out to the mid term, let's hope it is leading the way with getting blocking into the higher latitudes and over Greenland, a tougher ask.

Ahh classic pub run huh guys? GFS ensembles have upgraded the potential for cold in early Dec each successive run today 00z to 06z, 06z to 12z and now 12z to 18z Oh for that trend to continue through tomorrow.

Lot's of ifs buts and maybes But maybe if we can get somewhere around here day 6/7 we will be well in the game. So let's see where and how ECM models that shortwave low 96h+ Overall I think we will need to get the luck for all the pieces to fall into place but we need the pieces first.

Nice chart and like GFS but unlike UKMO pushes the troublesome shortwave low through to phase with the Euro trough.

Almost the classic retrograde pattern setting up on GFS, pinch of salt for now