Mike Poole

hey, @feb1991blizzard, how is this looking overall into Feb to you now? Because from where I’m standing it is looking good, the effects of the SSW are now showing impact and the MJO seems to be playing ball (although the MJO is an unreliable witness!). From the strat NAM chart here: I think now as important as the blues at our level at the bottom are, the reds at the top are also important as they will impart force on the downwelling if my understanding is correct. Make sure we get what has been promised!!

The uncertainty is highlighted clearly by the next cluster charts (T192-T240): Interestingly, little appetite for proper blocking over Greenland, plenty for blocking over scandi. Trough to SE of UK seemingly in all of them, that’s good. Anyone who thinks the modelling wrt UK cold isn’t improving needs to look at themselves!

ECM clusters T120-T168, there are two and the difference between them is a wedge, as illustrated here: Wedge is in the majority 28:23. Where’s your money?

Off on one, possibly here...but looking at the spread on the ECM ensembles T240: Look at where the uncertainty is, and more importantly where it isn’t. Is downstream going to prove to be the new upstream? I think there is still a possibility of total reverse zonal flow into February...only a possibility mind!

Yes, moving to T240: Impossible to resolve wedges at that range although lighter blues to the NNE !, displaced Azores high, and trough into Europe. What’s not to like?

I presume that’s what we call la la land! LoL! All the L’s. Look, now that most (read I!) have had some snow, this winter is already better than most in recent years. Second point, the SSW effects are continuing to drip feed themselves into the mix as only they know how (and us down here try to figure out every time it happens!). The MJO is coming to town. Expect the unexpected. Expect snow! Best chance for a cold Feb since 2009 in my opinion.

Hey, @Froze were the Days, when was the last time you had a good feeling about the model output?

It isn’t. It just isn’t. Hasn’t been all season and there is no driver to fire it up now! The charts that fire up the Atlantic are ALWAYS in FI and never verify. Which is not the usual winter fayre when the opposite happens!

Snow in the south, though marginal should be the right side of marginal, snow showers in the east. But only transient, as @nick sussex says, this one will not sustain. But the general pattern will throw up more opportunities into Feb. Edit , sorry that was in response to @Scandinavian High. post, forgot to quote it, D’oh!

ECM T144 yeah!!!

Wedge slider scenario on ECM at just T120:

Not sure about that, i think it is completely independent of UKMO, it is the JMA that was developed by UKMO?

There used to be many more ways that could result in cold for the UK in the past. That doesn’t seem to be true anymore, this thread probably not the place to discuss why that is, but in the warmer world, more disruption seems to be needed away from the status quo of westerlies, and a SSW provides that (70% of the time). Now most of us have had some snow, this one probably qualifies as one that did deliver, but the effects are likely to be seen still for a good further month yet, so let us judge it in March!

UKMO and GFS T120, nothing special for UK, GFS with more interest, but that low out west should pump up some heights somewhere;

No they are not overrated. Since 2011, all bar one significant snowfalls in Oxfordshire have been linked in some way to a SSW either recently, or in Mar 2013 a couple of months ago, but still linked to it. The exception was 10/12/17. Snow just doesn’t tend to happen in central southern England without something really disrupting the prevailing westerlies anymore. That doesn’t mean that a SSW can be expected to result in a deep freeze like 2018. It could just provide assistance to the kind of wedge type scenario that gave a snowy week in Jan 2013, and this one looks like it is going the same way. Big freezes - well they may occur infrequently and not because of a SSW - think Dec 2010. So provided expectations are tempered, SSWs are significant for cold in the south of England.

About 3 inches in Wantage. Lots of families out for walks and sledging. Starting to melt now.

Proper snow here now and settling. First decent snow I can remember since March 2018. Long walk in the snow will be my one outdoor exercise today!

Just started to snow here! Light at the moment. Here’s HARMONIE 0z take on the track and pivot, this model has been quite consistent on the last few runs: If anything, the precipitation looks a bit stronger on the radar though.

Thanks, yes my location was looking good to benefit from the pivot on last night’s high res models and so far I’m happy with what’s happening on the radar.

Here you are, shouldn’t be long! My location, about an hour away...

No it isn’t. The top half of that showing red dies out it is the bottom half that goes on to deliver whatever snow we get as per the latest models.

Yep, the // went bad, but the op GFS, that seems to have gone the full seahorse at T348:

Where’s this one going? GFS // T252 Answer, not where I thought it was at T282: But you can’t really get to Scandi high from where we were without a ridge across the UK, let’s see if it happens...

Nope same time, Meteociel is 1 hr ahead mate!

HARMONIE 18z take: Radar check about 10pm: Not bad, and there is more significant precipitation to the south of that band than the north, so the onward evolution looks consistent to me.