Mike Poole

Pub run T114: Just need this sodding feature to get with the rest of the cold evolution towards the UK:

Pub run T96: But I can see this vortex ripper scenario on this one as well, let’s watch and see…

Not a KO - because the strat vortex is strong and it would put the trop vortex back together again eventually, but like on ECM, it is a very interesting development today and one I wasn’t expecting on the models, to be honest. GFS out to T6 - gets later and later, I’ve got to go to work in the morning. Actually scrub that I have to work from home tomorrow and don’t have any meetings so is all good!

Hmmm, that cross polar ridge looks more likely on the 18z though. This idea has appeared today on the models, that the trop vortex could be totally marmalised without a SSW or anything from the strat. I’m not sure what it means yet but if it gains traction (as it seems to be doing as fast as omicron) we will have to consider how it might affect the UK. Longer term, would probably put us all in the freezer, shorter term, may limit the cold to the northern half of the country. Let’s see what the pub run has to say. Very interesting times!

Having watched the models chase this setup over the last few days, I’m not on board with the idea that suddenly from 0z to 12z, this high is going so far north it gets into orbit! (Yes I know that is not possible , it’s a metaphor). For once I will welcome the 0z runs with their more conservative zonal bias!

That’s for London, and it well and truly missed out on the cold on that ECM op run.

ECM clusters, now where do you start? T120-T168: OK, so there are 6 of them. All of them end up -NAO with some kind of heights into Greenland, including a full GH. T192-T240: It is a shame these aren’t NH view, but I think you can see that the vortex shredder option, which includes the op run, is Cluster 3. All -NAO by the end of the time period. T264+ Well, we don’t want cluster 1, others look OK but this is way way to far out in time to be relevant!

I kind of need to get my breath back after that ECM run! Some observations: Earlier this afternoon, I suggested that GFS would move to ECM 0z, it did, and was a classic run. I didn’t offer a prediction of what ECM would do, but I didn’t expect it to blow the trop vortex to smithereens, as it has, T240: This run - as it stands - is not good for Christmas snow for anyone south of Watford Gap services. But it would unlock potential for all sorts of evolutions down the line. You cannot easily put back together a vortex as smashed as this - I’ve seen SSWs do much less damage than this. So, it is day 9-10 anyway so to be counted as a freak run, for now anyway. Let’s look back to T120: Whether this works or not for the UK depends on stuff happening in two completely different places around the high. You’ve got the cold air (black arrow, probably drawn that a bit wrong but you get the idea) which needs to negotiate the Norwegian low, and Atlantic energy (yellow arrow) which needs to slide under the high. Talk about high risk, high reward! Get it right and we’ve a massive snowstorm on Christmas Day. But if not, the potential is still there for a few days later…

Wow, ECM into cloud cuckoo land on T216! A - Won’t happen. B - Cold too far north now.

ECM T192 v GFS: As suspected, the cold initially goes too far north, compared to GFS which hit the sweet spot, but plenty of time to adjust!

ECM T168 v GFS: Almost as good but not quite, the cold looks to track in a little further north on ECM.

ECM T144 v GFS and UKMO: It looks to me like the UKMO might bring in the cold air too far north here compared to GFS, ECM between the 2.

ECM T120 v GFS and UKMO: Looking good to me, so far. Lows from the west looking slidy.

ECM T96 v GFS and UKMO: Rather more GFS than UKMO - good after the run the GFS has just banged out!

First few frames 18.00, then approximately: T96 - 18.13 T120 - 18.20 T144 - 18.27 T168 - 18.33 T192 - 18.40 T216 - 18.48 T240 - 18.55

Very good, but it was talked about here too - all that talk about high risk high reward, that equates exactly to an Atlantic incursion that makes it , well, how far, does it go under, battleground etc. or does it win out? and that is where we are now. Hopefully, ECM calms the nerves in an hours time!

GEM not that good, in my opinion, like the ICON, the cold air reluctant to make it to the south, even by T222, won’t get snow off that: All part of the uncertainty range at the moment. Going to be very busy in here until this is sorted one way or the other, but we haven’t been in with a chance such as this for proper snowy Christmas weather for years.

GFS is an absolute cobra run, just look at the cold late on Christmas evening!

GFS looking very good T168:

ICON T180: Good Greenland block, but not a good hit with the plume of cold air, leaving the south way too mild. Not concerned, it is 7+ days away, and the earlier pattern looks good.

Afternoon folks! Should be a very interesting set of runs this afternoon. I think I am more confident of what the GFS will do than the others. I think it will inch a bit further to the ECM 0z, we’ve seen it many times in the past when it has a disagreement with the ECM, it shifts towards it over the course of a few runs (maybe not all the way though). I’m more interested in whether the ECM holds the line after its excellent 0z. I think it is about 60:40 that the block holds in a decent position into Christmas, at the moment. Let’s firm that up and then look at snow prospects. I don’t think it will be resolved tonight, but it would be good to go into tomorrow with more confidence than we have now.

Yes, I think this one went off the rails a while ago, and the T850s weren’t actually that good anyway. Still, I think all the op runs today have given us a really good idea of what the envelope of possibilities is, at the T168 range, and it is wide. Let’s hope tomorrows runs can narrow it a bit!!

GFS 18z T222: I know this all looks great from the point of view of cutting off the weak (well dead for a year) Atlantic, but these are quite odd charts that the models are now throwing out, things quite unusual could occur from this point (not the first run to show this either). We’re close to Christmas, the strat vortex influence is nowhere to be seen, and trop is running amok. Amazing to watch, but very difficult to predict what will actually transpire at the end of the day…all options on the table apart from an Atlantic barrel of stale beer!!

T198 and I think it looks like it is going under!

Would slide, I think. Whether GFS decides it will is another matter!