Model Output Discussion - Into February

[seabreeze86]

4 minutes ago, Mike Poole said:

Snow into the SE at T192 on the pub run, courtesy of that convenient cold pool:

That’s one hell of a persistent cold pool. Snows in southeast France for days 

 

[damianslaw]

33 minutes ago, Eagle Eye said:

Polar Vortex is shrinking quickly on the forecasts and there's a large Baroclinic tilt especially the further up you go. Best indication I've seen of a potential split/major weakening yet but it's still just a forecast. The dynamical Tropopause linking up with the Strat Vortex appears to be ready for quite a large Wavebreaking event via Eddy's as mentioned in my post earlier but will it be enough for a major SSW? You really shouldn't ask me for that . I'll try and learn a bit more about fluid dynamics over the next few days to see if I can get any closer to the answer. By then the GFS will have gone off the signal won't it .

Whilst the PV looks very strong to the NW, you would expect an atlantic onslaught right now, low pressure and westerlies in ascendancy, as was being predicted by many of the models for early Feb, alas instead we are once again locked into a settled high pressure spell, this has been the case for 2 years on and off, quite remarkable really.   I would not at all be surprised if it experiences a rapid knock out blow.

[bluearmy]

19 minutes ago, Mike Poole said:

Snow into the SE at T192 on the pub run, courtesy of that convenient cold pool:

The largest eps cluster day 6 almost has that cold pool reaching this far west

not yet completely dismissed although it’s size and depth has diminished somewhat on gfs over the past 36 hours …

 

[Battleground Snow]

10 minutes ago, bluearmy said:

The largest eps cluster day 6 almost has that cold pool reaching this far west

not yet completely dismissed although it’s size and depth has diminished somewhat on gfs over the past 36 hours …

 

Would be quite ironic if we get snow from the east (albeit in an unconventional manner) after all the debate on the gfs over the last few days

Control 150

Edited February 3, 2023 by Battleground Snow

[feb1991blizzard]

big reversal (split) right up top although location not great.

 

 

looks like SSW on the 10mb chart to me.

 

Edited February 3, 2023 by feb1991blizzard

[tight isobar]

The drag n dredge via cold pool accumulation is worthy!.. although I’d go as far to say again.. the micro anomaly’s are twisted knickers!!!.. and need unfolding of need.. that applying a back door- drill for more notable incursion... And NO all above wasn’t of crude implying .. serious note: there is a clear checker plause for a more notable drill @ 850 draw!!

[georgiedre]

10 minutes ago, feb1991blizzard said:

big reversal (split) right up top although location not great.

 

 

looks like SSW on the 10mb chart to me.

 

Funnily enough there were some experts (on ssw) saying about the pv moving to scandi for a possible split

[Mike Poole]

18 minutes ago, feb1991blizzard said:

big reversal (split) right up top although location not great.

 

 

looks like SSW on the 10mb chart to me.

 

Yep.  Gone!

Looks like some evidence of the quick trop response at the very end there, as we are half expecting, with a ridge from the pacific side through to the pole:

Edited February 3, 2023 by Mike Poole

[Johnp]

12 minutes ago, feb1991blizzard said:

big reversal (split) right up top although location not great.

 

 

looks like SSW on the 10mb chart to me.

 

PV certainly in disarray in deep FI

[Battleground Snow]

Haha control is crazy, 2 days of snow for the far south and then into this, similar to the OP from a few runs back.

 

[Don]

24 minutes ago, georgiedre said:

Funnily enough there were some experts (on ssw) saying about the pv moving to scandi for a possible split

I'm of the understanding that if the PV moves to Scandi, it is generally good news for us from a cold perspective?

[Don]

19 minutes ago, Battleground Snow said:

Haha control is crazy, 2 days of snow for the far south and then into this, similar to the OP from a few runs back.

 

I'm kind of thinking that the charts shown by the GFS a few days ago were a sign of things to come but perhaps too early?!

[minus10]

Looks like a colder set of gfes out to 14th...

[Nick B]

1 hour ago, Eagle Eye said:

Polar Vortex is shrinking quickly on the forecasts and there's a large Baroclinic tilt especially the further up you go. Best indication I've seen of a potential split/major weakening yet but it's still just a forecast. The dynamical Tropopause linking up with the Strat Vortex appears to be ready for quite a large Wavebreaking event via Eddy's as mentioned in my post earlier but will it be enough for a major SSW? You really shouldn't ask me for that . I'll try and learn a bit more about fluid dynamics over the next few days to see if I can get any closer to the answer. By then the GFS will have gone off the signal won't it .

Without wishing to pigeonhole your talents into purely the field of meteorology, if you do indeed wish in the future to pursue it as a career (and I think no-one here would have any doubts you've found a potential calling in it), I'll say this only because I haven't seen anyone else point it out yet (and it started bugging me solely because your posts are otherwise very high quality - keep them coming but keep on top of other subjects in class!)...

An eddy (small 'e' works just fine, not like the name, referring to a vortex characteristic in a fluid), and eddies, (again small 'e').

I say only because at some point in the future, you may wish to collate your postings as further evidence to submit to a university to which you may wish to apply. So, you really would want to use 'find and replace' to correct them.

And about the models (and not in reply to Mr. Eagle Eye!)...

I think we're going to see quite a few more days of disagreement in the 96-144 time period yet. Until perhaps another week or so has gone by. They're grappling with some pretty complex conundrums at the outer reaches of their ranges at the moment. Whether to form a Ural high / Aleutian low or not, how that then affects the stratosphere (i.e. severity, type and placement of the likely SSW), and then to extrapolate once again the knock-on effects from that in the troposphere, which in themselves, even with a QTR, are significantly further forward in time (min. 7-10 days beyond).

In addition,  we have an atmosphere hopefully primed for a quick response to drivers (e.g. MJO) which could well bring about a pattern change to something more favourable (or not!).

All in all, my thinking would be, it's still a little early to be hoping for the models to be settling down in these time frames. I mean, they're actually bl**dy good, but we do tend to keep demanding more from them and should keep in mind situations in which it's only natural output will be more chaotic.

TL:DR... over-analysis between runs right now might be less productive than it is even normally! I think trends will be more useful, if they can be spotted.

Edited February 4, 2023 by Nick B
Keep finding damn mistakes

[geordiekev]

2 minutes ago, minus10 said:

Looks like a colder set of gfes out to 14th...

Interesting how the 30 year mean tends to drop off as Feb goes on, quieter Atlantic?

[*Stormforce~beka*]

1 hour ago, RhHh said:

Off topic perhaps but does anyone know if Punxatawny Phil saw a shadow yesterday?

What the ruddy hell are you on about?! LOL

[lassie23]

2 minutes ago, *Stormforce~beka* said:

What the ruddy hell are you on about?! LOL

It's the Groundhog in America that uses the GFS to predict the weather.

[Don]

6 minutes ago, geordiekev said:

Interesting how the 30 year mean tends to drop off as Feb goes on, quieter Atlantic?

Yes, that caught my eye also.  As the days get longer, the cold gets stronger?!

[*Stormforce~beka*]

4 minutes ago, lassie23 said:

It's the Groundhog in America that uses the GFS to predict the weather.

I'm still non the wiser ...

[Johnp]

Just now, *Stormforce~beka* said:

I'm still non the wiser ...

You need to watch / google the film Groundhog Day and all will be clear. 

[nick sussex]

The detail next week still looks uncertain . The overall pattern has very good agreement but how much cold air is there to tap into is still hard to pin down.

You’re chasing cold pools around and these will often change run to run.

This is further complicated by low pressure over Iberia with some suggestion that might head north .

The flow into the UK looks se to ese and this will have low dew points .

And that could be important if that Iberian low does decide to head north ne.

Edited February 4, 2023 by nick sussex

[tight isobar]

Wel bone picking it’ is- but the gefs/ eps doesn’t take much index pattern looking!! The draw is there .. via top Scandinavian blocking signature!. These being the suite 12z format without 2m- and raw 850hpa!. Because it’s pointless, as an evolutionary trait/ prognosis!.. it’s purposefully worthy though!- as the structure of shallow = deep minamal plots can/ WILL mean vast difference.... and they are even out to day 5- not stone set!!!.. let me say THIS again.... a draw of worthwhile cold is still well open..... and maybe your eyes will be as we watch the HP fruition !!

[feb1991blizzard]

P12 - awesome, if it went out further, record breaking cold.

[KTtom]

Ironic or just blumin aggrivating, but just as we had a chance of pressure rise to the north east, the core of the PV decides to leave Greenland for the first time this winter and relocate there! 

 

[KTtom]

13 minutes ago, feb1991blizzard said:

P12 - awesome, if it went out further, record breaking cold.

Hmm not sure... I spot a Norwegian Shortwave!