Mike Poole

We still have 5 weeks of winter left, plus a March bonus if the weather wishes it that way. So what is on offer? ECM mean and spread T240: PV - horrible - but a lot of uncertainty closer to us, and maybe a pattern in Russia with low uncertainty on the spread which could put pressure on the strat vortex later. Clusters T192-T240: Potential here clusters 2 and 3, and T264+ Well a bit of a mess as you would expect, but the route to NE block is clearly still there. There has been nothing coupling the strat to the trop this year so far. If, with the strat vortex going so fast, a pattern from the trop is able to stick something sharp into it in the next couple of weeks it could fly apart…as I optimistically suggested in the strat thread. So we move into February, and some will have written that month off while I’m writing this, I expect, but hey ho! For the first time this year, eye’s up to the strat…

I can’t remember a recent winter when I’ve had so little to comment on in this thread. Normally, the strat is part and parcel of the whole winter narrative, but this year that narrative has just been one of a very strong strat vortex with no pressure put on it thus far. A couple of GFS runs showing something more interesting re pressure put on the strong strat vortex, allows a straw clutch, maybe? If pressure were to be exacted on the vortex in just the right place, could the fact that it is so strong actually work in our favour and cause a really energetic split event that blows it apart and downwells fast to the trop? Or am I just dreaming?

The idea of the high moving west into the Atlantic is strongly supported by the clusters T192-T240: How much that will allow a cold incursion from the NW is open to question. Cluster 1 looking more favourable.

Finally! Something that looks interesting within the 10 day range, GFS 18z at T228:

There is still time for us to reap rewards from this, given we are only half way through winter, that high over us, forecast to stay there for weeks, well it won’t stay there, will it, and if it moves to allow even a snifter from an easterly direction, the cold pool will be there.

Me too! I’m not sure if people saw earlier in the run something which turned out not to be there?

We are stuck in a rut. We are looking for a way out. GFS 18z has this at T192 and T240: Not budging, well it will have to in the end and the key question is does it budge to the northeast or northwest eventually, or sink? Still no clear answers so we continue to watch…

Well another day, another tranche of uninspiring model output. Look, clearly there is nothing imminent, so here’s the ECM clusters T264+ charts: The third cluster, all of 6 members looks fine, but the others have the UK under the same High it is now, in 15 days time. I have tried to stay positive in looking for the possibilities, and they were there on the models, so I make no apology for that. It’s not like the zero chance of cold brigade who fortell this and provide no model evidence at all (even though it is equally there on the models if they wanted to post the charts as evidence!). Anyway I have now concluded that there aren’t any realistic chances, for the rest of this month, the high is now too well set. I am beginning to wonder if this is the right hobby for me in winter. As a (now occasional) gambler, it sets off the same highs and lows, but how long do you play a fruit machine that never pays out? That seems to be the question now, last winter and this supposedly both had a fair few factors (teleconnections) in our favour and we still seem to have got diddly squat both years (noting this Feb still to come). Noting also my location, I know some in the north have done better. Regards Mike

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: