Model Output Discussion - Spring Has Sprung

[johncam]

 feb1991blizzard hi Mate , could you explain for us lesser mortals

[bluearmy]

 sebastiaan1973 yes Sebastian- finally a gfs op which splits through the strat and trop. Recent runs that have split high up but not low down and in the trop didn’t make much sense.  We take our chances with a split and hope it’s a big reversal or we play safe with an Asian displacement and hope that an Atlantic ridge can fill the space left rather than an atlantic trough (extended from the Canadian tpv)  which has been shown on recent gfs ops 

 Penguin16 if you are actually a penguin then I understand 

[Mike Poole]

 feb1991blizzard Yes, well, this at the end!

Completely smashed.  This signal is increasing - and given how the trop and strat have been connected pretty much all season, I think the strat vortex never recovered from the Canadian warming, my bet is on a very quick trop response if this happens.

[Cloud 10]

 feb1991blizzard

 

Boom indeed,strat PV unlikely to recover from that!

 

[Drifter]

 Penguin16 Admittedly it won’t seem that cold to a penguin…

Damn @bluearmy beat me to it. 

Edited February 7 by Drifter

[Daniel*]

Now you’re really talking.... GFS 12z emphatically splitting polar vortex.

[Frosty.]

Perhaps I’m clutching at straws…but early May could be cold? ..on a more serious note, this winter seems to be fizzling out before it ever really started and honestly, the experts can’t be blamed, they are only looking at the same models we are and drawing a conclusion..shame this winter, for the majority, is another carp fest! ..but the bright spot is, I have a few more snowy pictures from my house to enjoy! ️ 

 

Edited February 7 by Frosty.

[feb1991blizzard]

 johncam The vortex is split (favourably) right the way through the atmosphere.

If you look at the charts you will see the low numbers (heights) either side of a ridge (high numbers), that means there is two lobes of vortex split far and wide.

 

 

 

 

 

 

 

 

 

Edited February 7 by feb1991blizzard

[Kentspur]

The 850s don't seem to add up to the actual pressure charts shown on GFS again its on the mild end if not an outlier +12 around Norway! What the??!

 

 

Edited February 7 by Kentspur

[Scott Ingham]

 feb1991blizzard That split is close to perfect with the right balance of energy to stop a west based -NAO and enough cold to head west from Eastern Europe! This Strat run has me tentatively out of hibernation!

[Drifter]

 Kentspur That value around Norway can happen and is due to a Foehn affect. 

It wouldn’t spread our way as it would disperse once the conditions are no longer favourable (wind moving across mountains). 

Edited February 7 by Drifter

[phil nw.]

The interest is around T168 where all the runs show the Atlantic jet buckling as it comes against the ridging developing through the Uk.

We see they all try to move to the start of an easterly but not quite getting there at that stage.I do like the ukmo run though it seems less progressive at that stage and we can see the cold from Scandinavia starting to move this way.

The low that has finally moved east towards Denmark more of a feature and is almost acting like a trigger for the easterly. 

[feb1991blizzard]

 Scott Ingham

Yes, that's the best Strat chart i've seen for a good 5 or 6 years.

[Scott Ingham]

 feb1991blizzard yep! That’s also my opinion! The best since the 2018 split!

What date did the split happen in 2018? I can’t remember!

Edited February 7 by Scott Ingham

[feb1991blizzard]

 Scott Ingham

Cant remember exactly, early - mid feb i think wave one and then wave 2.

[Mike Poole]

GFS 12z T378, zonal winds at -19 m/s:

Just wonder how much the big Russian high earlier in the run, and on recent runs, has to do with that.

[Lukesluckybunch]

It wouldn't surprise me though..if that's how we end up at 384..boundary between chilly air and freezing air is clear too see!

[damianslaw]

Feel the direction through next week is still very unclear, and won't be until the low pressure moving in from today and unusually heading NW, though UKMO does then clear it east..clears away. Hence , I've been sitting back from commenting on recent model runs and will continue to do so.

Interesting to see GFS12z showing a path to colder air from the NE eventually followed likely be a retrogressive high, one run did it yesterday.. this could well be the direction of travel further into Feb, but we may have a milder southerly feed first. 

[sebastiaan1973]

 Scott Ingham 12th of february

[Scott Ingham]

 feb1991blizzard I’ll have a look I’m just trying to work out if we’ll have the right conditions earlier or later than 2018 which obviously will make a difference in times of increased solar interference. I suspect this year will be a much quicker down well however as the atmosphere appears far more coupled than 2018

[Scott Ingham]

 sebastiaan1973 ahhh thanks for that Seb it’s saved me some time! So a later ssw but possibly a qtr this year compared… interesting!

[Chesil View]

Laughable continuity on the gfs op.

Going from multiple runs of ultra mild soutwesterlies. To an easterly then a slowly retrogressing UK high.

 

[Singularity]

About time a GFS run managed to keep the Atlantic at bay later next week. As you can see from the rest of the run, it has a big knock on effect as for a week or so afterward, there is nothing in the pipeline to give the Atlantic another push eastward.

All it took was a slight revision of the trough orientation toward negatively tilted during the middle stages of next week. I was surprised how many of the overnight EPS suite had that negative tilt - let’s see what the midday suite has going on later.

[IDO]

I think that split-retrogression of the Siberian high via Scandi/N Europe to a UK high is better than a high stuck in Eastern Europe, and both GEM and GFS have this:

Though two days apart (GEM D9-GFS D11)! The models still fluid in this evolution, and this was the likely route 3-5 days ago deep in FI on the GFS though it keeps getting discarding and being resurrected. The GEFS mean to D14 are similar to the 06z.

I think it's a case of letting the models sort themselves out. The Strat experts on here are hopeful that we get a coupling and a major reset in the NH trop so some good news.

[bluearmy]

Gefs end week 2 are further south on the lw Atlantic trough trying to get in 

that’s a plus