Nice 'n' zonal

Quite a big change on the ECM 12z operational and unfortunately also on the Ensemble mean as well. The -5 isotherm was pretty much enveloping the whole of the UK on the 0z mean, but now it's conspicuous by its absence in the 7-10 day time frame.

One run and all that, and I daresay this is far, far from resolved.

But pretty much all of the 12z's have been two steps backwards. I am pretty sure this is the one this time and there is time for it to bounce back and deliver a notably cold 2-3 weeks of February, but the 12z's provide much needed caution to any aspirations of a severe spell.

 I was only saying a couple of days ago how it looked like the overnight and morning runs were far less amplified than the afternoon and evening runs and now its seems to have reversed lol. Whether or not this is the models struggling with conflicting signals be it la Nina, MJO, or downwelling, or which one will play the more dominant role in the synoptics to come. Or perhaps covid issues ie lack of data who knows but imho nothing has changed the models look all over the place this afternoon and I would not be surprised if we see much more amplified and nirvana, winter wonderland synoptics by the morning if not sooner.

I did say earlier that ensembles might flip mild if we were unlucky. But didn't expect it to be the ECM ensembles. You couldn't make it up. Hopefully they flip cold again tomorrow.

https://www.meteociel.fr/cartes_obs/ecmwfens_display.php?x=316&y=140&run=12&type=0&runpara=0

Give me a break 🤣

Was a little surprised by the ECM ens being noticeably milder for down here, they've been pretty steady for the most part but a definite shift from this morning and last few days.

ECMWF 14-day ensemble weather forecast for Tunbridge Wells District | Meteologix.com

Time for it to move back of course so won't be calling anything for a while yet, I'd imagine by 12z on Sunday we'll be able to see if this is a blip or another FI only cold spell (down here of course, further North still looks good for cold regardless).  

FWIW the 12z GFS ens looked alright to me - reasonable suggestion of 4 days or so of cold air for the South in the mid term before a fairly strong signal for a warm up. 

I think there is every chance it could all flip cold tomorrow, models are in a state of chaos.

Relying on heights coming out of the Arctic to link with heights to our North has a huge failure rate since 1987. Let's forget the GFS for the moment. The differences between the poorer outcomes from the ECM, GEM and UKMO at T144 are enough for now to give this legs to tomorrow.

Good call. 

I think so too as we are seeing flips each run and if one run goes mild another flips cold like we have seen of late - I doubt this would flip even more mild tomorrow - even the Met mention easterlies in their longer range forecast and surely the Met have access to more data than us!? Or don't they?

Who's anxious about the 18z model outputs?

They do, but events show us time and again that their longer range outlook is hostage to the vagaries of the changes that we view on the free NWP in that vital T120-168 range.

18z throws up a very rare set up (if not frigidly cold) in deep FI, fascinating from an ivory tower academic model watching perspective at day 9, only for HP to settle at day 10.  To be honest, round here we really need a dry out, so that would be welcome.

Amen to that!