Mike Poole

Think the ECM spilt its coffee a bit before that!

Aye, and this is going to be one of them!

Not sure, and they are both 18z runs. At as early as T60, I’m probably focussing on the differences you can see without a magnifying glass! Any which way, I’m sure the morning runs will find a way to tear it all apart tomorrow! Night folks!

Anyway, ARPEGE 18z v pub run T60: That’s as far as the run goes, but looks a lot more slidy to me! Again note the differences at just T60. Basically we want that two low system looking more like a penny farthing! Edit, and I’ve added the wedgeometer in black pen! Much stronger on the ARPEGE.

This obsession with the control run in here never ceases to amaze me, it isn’t an op run, it is a diagnostic for the ensemble suite. Wonder if it is because at this time of night there aren’t many runs coming out…ARPEGE due to T60 imminently. I’ve been musing why people don’t usually post this one, and have come to the conclusion it is because most people can’t spell it, I’ve seen APEGE, APERGE, APREEGE, and many more over the years. Weird!

It’s a bit splitting hairs at T54, but here’s the pub run v 12z T60: You can see that low A is a little bit deeper and low B is a little bit less deep, with the situation on the knife edge, this redistribution in the Atlantic could make the difference between low B sliding and not.

So to the pub run then? Roll that dice: I’ve not really felt moved to post in here as often as maybe I would usually during this fiasco, and it is because while it is fun to post the charts as they run out, it has been very difficult after we’ve seen a suite of runs (for me usually the 12z runs) to produce a summary of where I think we are headed on any timescale (from T72 on). It is that uncertain. Anyway, pub run rolling now…

Think I’m in a similar position, but it is still brown trousers time! But there must be some correction on the GFS 18z, surely!

At the stupid range <T72 we are now at, it is worth remembering that ECMWF stands for European Centre for Medium-Range Weather Forecasts. The very big uncertainties are now no longer in the medium range so one has to say at the very least, all bets are off wrt which model is better, in my view.

Yes, fixed now! But you can see that the ECM has the low more developed and the heights (wedge) more squeezed even at T72. T72 is FI. Wow!

ECM T72 v GEM:

Like I said before the afternoon runs, I wasn’t going to call it based on the morning runs. Never call any cold evolution dead on the morning runs, there is something about them that tips them in the direction of zonal - only a bit, but on a knife edge situation like this, a bit is more than enough it seems. Excellent UKMO and GEM this evening, can the ECM deliver? And in particular, I note the GEM has been more consistent than any other model on this over the last few tortuous days.

Excellent post @Catacol - but there is a little more work to do to explain why - in the northern hemisphere (although interestingly not in the southern hemisphere) the models consistently verify better in winter than summer! It may be along the lines +NAO winter >> summer > -NAO winter, but because the +NAO regime is more common, that gives the overall result that the models verify better in winter. Edit: I see @davehsug beat me to it! By the way, I’m not calling this until we have see the 12z runs. Too much uncertainty, some folks maybe a little bit trigger happy this morning.

Just glanced through the posts, probably right decision not to view it in detail! Further south, but less precipitation it would seem. Some IMBY posting going on (as you would totally expect). No reason to bin it, perfectly plausible run, I’d say, but, hey ho, on to the 0z runs, or in my case probably the 12z runs!

Well, I did have a look at the clusters, and not good, not bad, just a whole load of uncertainty which I don’t have the energy today to unpack again. It’s a mess, and anyone who tells you how it is going to pan out is either overconfident, wrong or arrogant, or a mix of all 3. The envelope of uncertainty is massive even for the 25th. Not bothering with the 18z today, it won’t give us any more info. Back tomorrow.

Thanks, and good night.

He’s just playing! I don’t know why the MO let him twitter this stuff, to be honest, other to be a controlled source of leaks! He’s the only forecaster from the Met we hear from - maybe a comms thing? Also, he often quotes the GFS when we have it on good authority in here (although it is going back a few years) that the MO doesn’t rate it. Everyone says he’s a nice bloke, but it seems to me he just plays to the crowds, because somebody from the MO has to.

Yes, strongly agree with this, the ECM is an improvement and a massive move towards the others, not in time for Christmas, but hey ho!

ECM T168, a new hope?

ECM T144: And would you Adam and Eve it, but the lack of Atlantic inroads when we were looking for the snow, now mean a surge of heights to our west: Which looks to me to have power to add…

ECM T120 v GFS and UKMO: ECM looks a bit weird here with what is undercutting. Less strong block but nothing from the Atlantic either? Can’t see much snow from this.

ECM T96 v GFS and UKMO: Midway between the other two re strength of block I’d say, favouring GFS more. So a move towards consensus.

So, this is the big one, right now!! I said before the 12z runs that I favoured GFS because it was showing solutions against its own bias, GFS delivered on 12z, so now is the time for ECM to come in line…we hope…we will see…

Do you mean tomorrow, or is Tom some weird nickname for the ECM?

JMA T108 looks spectacular: And, actually, since we have time for improvements, it looks like what sliding under a block should look like!