Mike Poole

Here:

ECM clusters T192-T240: 5 of them, and cluster 1 follows the op with 15 members, and this is the one I think has the most potential once we’ve got to this point. So 30% chance. The others all look a bit of a mess to me, cold NW’ly from 3 and 5 maybe. But there is so much uncertainty in this, that is perhaps best to point to the highest probability cluster 1 and leave it at that for now. But for sure, plenty to watch as the cherry muncher charts his path through the next 10 days…

Yes, Don, from where we are now that’s exactly what we must hope. Since my joining netweather, the strat has always been a crucial part of the discussion around UK winter prospects, except for this year, where it just roars away overhead, with very limited effect on our weather down here: On it goes… But if it did couple now properly with the trop, there’s no time for the precursor mechanisms to a SSW to happen in time for any hypothetical SSW to affect winter or even early spring in terms of UK cold. It has been interesting to watch something different this year, but my lack of posts in here is just because there is nothing of interest on the cards re the strat and never has been this winter.

ECM T240: I don’t think this chart is likely to verify at all, but if it did, the only option for the high is to retrogress, and that would bring into play the whole trop vortex in another few days. It has often been said we need several bites at the cherry for a really cold spell, well this drawn out saga takes the shortcake, but it is still possible it ends good, because there is literally nothing coming off the Atlantic, so even if it runs into Feb and we keep seeing these attempts to develop a decent ridge, one of them will surely deliver, I would have thought.

Ha, haven’t even thought about summer yet. What strikes me is that the Atlantic has been dead since about this time last year. I remember wondering in autumn whether it would resurge, hoping it would stay in slumber into winter - it has done, but it sticks in the throat that we’ve still not managed to land anything remotely cold anyway! If the pattern persists, plus the strengthened and displaced Azores high, we could be wondering the same in the run up to summer. UKMO and GFS this morning are like chalk and cheese at T120 and even earlier. I can’t decided whether these GFS solutions are just part of the envelope of uncertainty, or whether it is seeing something different to the other models. If the latter, then the next question is what it seeing nonsense or not? I now suspect it is, but the 12z suite should consign the early (T144) northerly to the bin. Later prospects still in play. We will see…

Yes, lets hope so, I see what you are saying, and it would be nice if there is a Plan B in case Plan A goes the way of the pear !

Yes, I noticed that on the extended! But didn’t post it because of the obvious massive uncertainties earlier. If you look at today as a whole since the 0z runs, it is a massive upgrade. And because the uncertainty is at such short range, it will be resolved in the next 24 hours, probably, 36 certainly, and you want to be going into that crucial period with your star in the ascendancy! ️

Holy Moly, this is on a knife edge, ECM clusters T120-T168: It’s too far east on clusters 1 and 2, but clusters 3 and 4 we are very much in the game. They total 14 out of 51 members, so I reckon we sit on a 28% chance overnight, awaiting the morning runs!

That AAM CFS chart you posted is from the 3rd January - that site hardly ever gets updated, and since I have no access to any other AAM charts, that is why I have stopped including AAM in any analysis of the model output.

No, comments above are correct, there is nothing decent coming on this run at T120: Too much of a vortex lobe to the NW.

It can be quite difficult to tell, the two models extrapolate the sea level pressure in that region so differently, so I’d wait and see.

ECM and GFS T96 and the ECM looks to show promise to me at this early stage:

ECM clusters in that key timeframe T120-T168, and there are 5, all bar one chart has purple border - so Atlantic ridge regime. We kind of know that from looking at the op runs, the devil is in the detail. The ideal one (which will include the GFS and GEM evolution) is cluster 2, which puts up a proper ridge and brings down the northerly. 10 members, so 20% chance of that one. Cluster 1 never clears the high from the UK and doesn’t ridge north into Greenland, clusters 3 and 4 look too Far East for the UK to benefit, op is in cluster 4. Cluster 5 looks the weakest blocking. So the proper cold outlook, at this early timeframe looks to be about 20%. I should remind some people that 20% is not 0% as it is regularly cracked up to be by those who are 100% certain (for some reason I cannot fathom) there is not going to be any cold blocked evolution in January. And to be honest, in all of this chase, no-one has to my knowledge claimed more than about a 1/3 chance of a cold blocked evolution, obviously that fluctuates with the model runs. There are 6 clusters showing all sorts for the next T192-T240 timeframe, so I think all predictive capability is lost by then so i won’t post them!

No, it has missed the chance to get WAA up the west side of Greenland, which is so important to get anything to stick there.

Yes, I always think of GEM as one of the big 4 since its upgrade a couple of years ago. There are no stats for the ICON on the website I use for verification stats. If anyone has any, might be interesting to compare?

It’s doing quite well at day 5 in 3rd place at the moment, 0z: 12z:

GEM T144 looking good so far too:

Great run so far from the GFS 12z. Here at T144, there is a good split of the vortex, leaving just enough on the Canadian side to fuel WAA west of Greenland. Leads to a decent and cold northerly at T180. Good to see this in the mix.

ECM clusters T192-T240: This is now the timescale we were tracking with the T264+ clusters a day or two ago, so let’s see what is currently being predicted and how it compares with previous. Cluster 1, while designated Atlantic ridge (purple border) in fact has the high stubbornly refusing to shift from the UK. Cluster 2, this one is similar to a couple of op runs recently with the Azores high sluggish to retract, but looks like it will get there in the end. Cluster 3, is the one we want with a proper northerly developing. Cluster 4, is also with much promise and a northerly flow. Most optimistic take, clusters 3 and 4 total 18 out of 51. That’s todays odds! It isn’t worth posting the T264+ clusters, there are 5 and look a complete mess, you can tell when there is just no signal whatsoever and that about sums it up. Finally, the spread at T168 is worth a mention: At later times than this, there is uncertainty all over the place, but not a localised hot spot like this between Greenland and Iceland. Make of it what you will, but I’d kind of mark it out as something that needs to be resolved before we put any faith in the later output.

One of those where you’d like to see the next two frames from ECM T240: I think a modest step away from cold today on the models, so a lower probability than yesterday of landing anything noteworthy, a decent short term toppler still very much on the cards. On to tomorrow.

Kind of asking a lot of this area on this one, T240:

Well it kind of has to from here, doesn’t it? (Know I said I wasn’t going to stay up for the pub run, but hey ho!). T204:

So where are we right now? I’m not staying up for the pub run, early start tomorrow! Well for a week or so now this place has been a strange place with those of a cold persuasion (I think it is fair to say) looking fairly long range for thin gruel, and of course cherry picking fruity ensemble members, while those who are convinced there is no cold to come at all in January (I think it is also fair to say) saying so repeatedly without backing it up with any evidence at all (I exempt @Catacol and @CreweCold from that generalisation because they have provided their reasoning). But I sense a shift based on the model output today: The evolution after the reliable relys heavily on where the bulk of the trop PV ends up, and while there is definitely an early movement to the east, whether it all stays there, how much remains as a Canadian lobe has been massively open to question. The 12z suite, and ECM clusters, seem to be reinforcing the idea that the shift of the PV to the east will be more substantial, allowing an Atlantic ridge to form and the Azores high to retract, thereby allowing a trough into Southern Europe. For a longer term cold pattern, this is now a 40% chance at most (going off the 12z clusters 20/51 - that could be a flash in the pan, need to see it repeated on next couple of runs). For shorter term northerlies (topplers), I would say there is a better chance than 40% (75%?) we will see something the week after next. Today, with the ECM 12z we now have something to work with within 10 days. There is still massive uncertainty about how the next 2 weeks pan out, and anyone saying they know now are talking out of their backsides. I think there will be some twists and turns to come if we are to get this down to T0! Best regards Mike

Also, in case you hadn’t spotted it, nerdy point here!, the representative perturbation chosen to illustrate the cluster was ‘perturbation 0’ - which is the control. (Op run obviously finishes at T240.)

ECM clusters T264+ And, well, the 20 member Atlantic ridge cluster 1 - we will take all you’ve got of those !