Both the ECM and the GFS operationals were at the both on the mild side of their respective suites down here. I suspect the goose will finally get away by Tuesday after we have completely exhausted ourselves chasing it ! 

I'm going out into the sunshine before the drizzle arrives later. 

/charts/web/classical_meteogram?facets=undefined&time=2021013100,0,2021013100&epsgram=classical_10d&lat=51.57&lon=-0.83&station_name=Reading,%20United%20Kingdom

 

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I wouldn’t bin it, rather say it is in a very small minority. It could always be correct and the vast majority of other output could be wrong (including the previous three op runs which had different scenarios).

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The theme of a slow motion car crash continues.

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It all just screams uncertainty at the moment. ECM quite a big mild outlier especially towards the end. GFS op not great, but the ens give hope all be it with lots of scatter.
As ever more runs needed to resolve the tricky mid term evolution. What happens to that LP system just to our West seems to be the key to either a cold route or mild route, and it kind of depends which route the op takes, dictates the mood.

Could be all change again on th 06z!

http://www.wxmaps.org/pix/temp4 - a very large mass of very cold air over NE Europe in week 2 but with sharp temp gradient around its edges , across Germany and alas! across the N Sea.

GFS adopting a half-hearted approach to easterlies with weak LPs tracking south Wed 3rd and Mon 8th but the isobars run from the Balkans, not the baltic so not that cold. Interesting storm off N Ireland Sun 14th 955mb combining with HP over Finland to produce S gales shifting to SE and offering the end-of-run possibility of much colder stuff esp in the N

GEFS - the S drops into a cold spell Fri 5th - Tue 9th (Scotland colder throughout) after which wide variation with op and control going in different directions - take your pick from 13C below norm (control) to an equal amount above (Scotland similar but less extreme). The exact direction of any NE/E/SE-ly is going to be critical and 'subject to change without notice'! Rain or snow esp in N around Wed 3rd and intermittently thereafter. 

ECM similar to GFS at first but developing a deeper area of LP Mon 8th and holding it back on the Atlantic to give strong and mild S-lies by  Wed 10th

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Yes, the ECM goes off on its own as early as Tuesday looking at the ensembles and come Friday it is isolated leaving the other 50 below. The control run from ECM much better end brings in the cold along with the others. Very strange ECM run today.

Martin

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F

You are the forums biggest drama queen 😁 I'd be getting the garden tools out if that run comes off, would be mild enough to get in the garden without my big coat 👍

Off-topic slightly but the consistency off the cold in the far north of the U.K. (250 miles or so north of here), which has been modelled well has led to some unusually chilly situations. 

https://www.bbc.co.uk/news/av/uk-scotland-55864302

It doesn’t look like warming up any time  soon http://modeles16.meteociel.fr/modeles/gensp/graphe_ens3.php?x=&ext=1&y=&run=0&lat=60.2834008097&lon=-1.41509433962&runpara=0 

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Ive been on or following this forum for nearly 20 years. I’m definitely not. I’ve also seen the fallout when easterlys more often than not go wrong. 

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That'll be Dover harbour next week. 

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Again good model watching it would be boring if we had consensus across the board. Looking at the models would say we will get a cold snap as opposed to spell.

Looking fairly solid for scotland doc, good luck 👍

So looking at the ensembles (and not the op runs which, while useful, really aren't the be-all and end-all), for London, we have:

GEFS - solid agreement of a cold few days starting next weekend. Mean 3C or below (link), dominant cold cluster.

EPS - solid agreement of a cold few days starting next weekend. Mean 3C or below (link), dominant cold cluster.

GEM - solid agreement of a cold few days starting next weekend. Mean 3C (link), dominant cold cluster.

At the moment, for the models that go out that far, we have excellent agreement across the board on a cold snap, if not spell, next weekend and into the first part of the following week. Snow? We'll see - and, of course, for balance there is a small (~10-20% chance, depending on model) of it not getting especially cold.

It's a great morning for those down here who like cold. I'll leave untangling the spaghetti for other areas to the rest of you!

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Gfs  Para is a lovely cold and snowy run from day 6 to 16.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=192&mode=0&runpara=1

 

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This puzzles me. We have the coldest set of GEFS ensembles of the past 17 runs (and indeed longer than that). We have EPS which has been lowering the means for the past few runs too, now showing a solid signal for decent cold for a few days. And even GEM, which in my experience is usually the least enthusiastic in terms of ensemble cold, is on board.

It could still go tits up, of course, but there's not much I can objectively see to say that's likely at the moment.

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Why? Who knows, ask the divine being / god (if you believe in that stuff). If not, chaos theory will give you the answer you want.

What's for sure is that the ECM op is NOT the perfect arbiter of what will happen, it just happens that averaged out over the entire northern hemisphere (which is quite large) it's the best model. That doesn't mean it always gets our little region (which is quite small) correct all the time either.

In fact, all of the models, GEM, MetO, GFS and yes, ECM, have had ops that have flip-flopped all over the place over the past few days. It's what they're wont to do in situations like this and, after all, nobody cares if a raging zonal flow shifts north or south by 200 miles... but that makes a hell of a difference in our current circumstances and it's much more noticable.

Or, in other words, nothing to worry about. Look at the whole suites, not just bits of them in isolation.

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Cold spells never happen without ECM on board. I expect a major flip tonight from other models and the all too predictable meltdown on weather forums

 

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I think what Justin is alluding to is the propensity for one model that goes against the rest to be proved correct in scuppering a cold spell. We've even seen the ICON and GEM stand alone with poor solutions and be proved correct against all others so when the ECM keeps churning out spoiliers (albeit not consitent ways of spoiling) then it has to be considered a very big elephant in the room. It all hinges on this low and how the models deal with it. The plus for me this morning is the UKMO at T120, which should always be respected and has nothing to do with the ECM view. The negative is that past failures are a guide to future ones in this game.

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that doesn’t happen too often. Remember my dad talking about ‘ice in the harbour’ in the 80s but never saw it for myself (even in 95 when we had consistent low temps and burst pipes everywhere). We were only 40 miles north mind.

ECM is on board. Not my fault if you ignore 98% of it!

ECM isn't going against the rest though, it's in full agreement with GFS and GEM on a cold snap/spell this coming weekend.

Again, don't ignore 98% of the model!

Now, you'd have a point (as would Justin) if the EPS/GEM ensembles/GFS ensembles had flipped, but they haven't. Not yet, anyway, but we'll worry about that when and if they do.

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I am yearning for some Spring warmth now and it help with Corona too. 

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Always a worry when the ECM doesn't play ball. Even if its ensembles are ok, it still leaves a nagging doubt that its assumed high resolution op is picking up something the members aren't. GEM is good and a model that's been performing well recently. GFS for me, has always been Vyvyan (young ones) of the group. In isolation, the op briefly flirts with cold before jumping back up again. A sign similar to ECM finding something not right? Maybe. The Para has been consistently showing large northern blocks in various places, its supposed to replace the op in the future so you'd consider it to be of a better standard.

With all the information at hand you'd think cold was favoured, but until the creases get ironed out I'm not overly confident. I'm going to continue to read what the pros take on it is and go from there.

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They will on the 12zs, just wait. We all know how this story plays out. We've been through it so many times

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Precisely.

There have been just two notable cold spells in the past 11 years here: Dec 2010 and late Feb 2018. In both cases there was cross model agreement at +144.

Since 2010 there have been countless tits up scenarios where there has been huge excitement about a forthcoming easterly. In every case, one model has been on its own in showing a different outcome to cold. In every case, the outlier has been closer to the mark.

That is completely unscientific but why I refuse to get remotely excited about this latest slow motion train wreck.

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The ensembles are the ECM. You may as well just look at perturbation 3 in isolation, or maybe 27, or even the control run (which, like the majority of ensemble members, is consistent).

It's the whole point of the ensembles - it helps show whether an op is representative, or whether it's gone off on one.

I genuinely can't see why there's the wrist-slashing going on, but there you go. Maybe you lot are all correct and even though it's not being shown, it'll come crashing down. I'd rather rely on maths and stats, frankly, and that shows at the moment we're in for a cold snap or spell.

 

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