Model output discussion - Post SSW - Will it turn cold?

[The Eagle]

After all this time and still drooling over 240+ charts. Easy to understand the frustration some have.

Need to see events move forward at this stage.

 

 

[tight isobar]

2 minutes ago, TheBeastFromTheEAST said:

Just to add to that, Shirley  ☺ if the sea temp is a little warmer come March that could beef up the snow showers as they come in from the ease? 

Covective potential is massive- via lots of output!!!

[Catacol]

Whether it is the fast track GFS solution - GEFS here for 10 days

or the slightly slower ECM evolution, here again EPS for 10 days

..we are heading in the same direction. At this stage I dont think there is much more to say - we are still drumming the fingers a bit as we count the hours until heights start to rise. Way back early last week GFS op suggested strongly this as the weekend coming - and we have shorter range data now in agreement. GP posted a wise gently gently post earlier, indicating the movement of the high may not be as fast as we would like - but with such dramatic activity in the stratosphere with slightly uncertain speed of tropospheric response this is very much a watch and see scenario as things unfold. I wouldnt like to speculate on what is going to happen next week - it could be snowy nirvana in time for the next round of the 6Nations, or maybe just cold, clear and frosty while we wait for impacts in the final week of the month. Either way a refreshing change to weeks on end of wind and rain the south has had to endure - yet more coming down as I type :-(

 

[Duane S.]

11 minutes ago, TheBeastFromTheEAST said:

Just to add to that, Shirley  ☺ if the sea temp is a little warmer come March that could beef up the snow showers as they come in from the bitter East? 

Because of the lag effect, they are generally still dropping through March. The warming sun on the other hand will help boost energy over land

[Rayth]

A snowy Calcutta Cup @Catacol ? 

what I find fascinating is the OP’s constantly veering to the mild of their ensemble , but their mean having none of this , there just has to be a jaw dropper of an op run coming , really interested if this forecast -NAO happens , it’s been elusive to going  negative for the entire winter ! And with Easter coming early this year ... frozen bunny anyone ? 

 

[Coopsy]

Don't worry about sea temps - If you look at the monthly averages there's minimal difference between Feb and March. In fact some areas even dip in March. 

https://www.seatemperature.org/europe/united-kingdom/

 

[Daniel*]

7 minutes ago, Raythan said:

A snowy Calcutta Cup @Catacol ? 

what I find fascinating is the OP’s constantly veering to the mild of their ensemble , but their mean having none of this , there just has to be a jaw dropper of an op run coming , really interested if this forecast -NAO happens , it’s been elusive to going  negative for the entire winter ! And with Easter coming early this year ... frozen bunny anyone ? 

 

Usually it’s the other way around we get a belter of an OP and it has very limited support how often does that end in tears? In time, soon, I expect the OP’s to replicate. Surely highly or even certain too, cross model agreement across EPS and gfs ens mean agreement on taking NAO negative from the final week of Feb. Frozen squirrel! 

[SMU]

This is the IKON 66

note that for the evolution 97-144 we are dealing with the energy seperation between the shortwave & the parent low - then the subsequent ridging inbetween .

Hence why at the mo there is still large variation in ensembles across the piste

 

This shortwave can also be the trigger shortwave for the cold to drop in earlier like the NAVGEM ...

[Daniel*]

The negative NAO itself is being put forward looking at EPS it may go negative in 3 days time only slight and from there the only way is down from late Feb into March it’s quite notably negative.

[Mike Poole]

Before the 12z's roll, I' m considering the question:

'are the models struggling following the SSW?'

I say NO.

Virtually every run from every model that I've viewed since the SSW has had an evolution towards a UK high this weekend, and that high then migrating N, NW or NE into next week.

Even beyond what we would normally call the reliable, there is still consistency.  Trouble is, exactly where the block sets up matters greatly from the point of view of snow for the UK.  And this can't be resolved on the next set, the 18's, tomorrow or even for a few days, we're expecting too much from the models!

But that won't stop me watching the 12's!

[Optimus Prime]

22 minutes ago, s4lancia said:

Because of the lag effect, they are generally still dropping through March. The warming sun on the other hand will help boost energy over land

CAPE values, whilst will be a bit higher I suspect it's effect in terms of convection will be limited compared to a typical winter month. With cold that intense, however, plenty of convection for the east and south.

[wiltshire weather]

The MetO have really ramped up the wording on their extended forecast for the period up to the end of Feb "Wintry showers may develop,with the potential for some significant snowfalls focused on southern, central or eastern areas. "

Seems to reflect very much for example what the 06Z GFS is showing for Sunday 25/02

Edited February 14, 2018 by wiltshire weather

[Herefordweather]

I’m expecting a stonking run from the GFS. Only to be brought back down to earth by the ECM later on.

The Met Office wording certainly more positive mind.

[Rayth]

3 minutes ago, Herefordweather said:

I’m expecting a stonking run from the GFS. Only to be brought back down to earth by the ECM later on.

The Met Office wording certainly more positive mind.

With that wording I’m expecting Winterfell from the  UKMO in the days to come 

Edited February 14, 2018 by Raythan

[Met4Cast]

Not to be pessimistic but didn't the Met Office say something similar in 2012? 

It's a good update for sure and quite telling on what MOGREPS is going for, the ops are deviating with each run which is why this thread is up and down like a rollercoaster but the ensembles have remained firm and have been improving with each run.

ICON or IKON if you're Steve brings in the Easterly Day 6

Edited February 14, 2018 by Daniel Smith

[karlos1983]

ICON next Tuesday 

Starting to drag in air from the east

Edited February 14, 2018 by karlos1983

[frosty ground]

Just now, karlos1983 said:

ICON next Tuesday 

Starting to drag in air from the east

Closer view.

[Met4Cast]

Wow. Massive improvement from the ICON, better heights, colder air coming in earlier

[Daniel*]

2 minutes ago, Daniel Smith said:

Wow. Massive improvement from the ICON, better heights, colder air coming in earlier

Could this be one of those rare 12z suites where everything flips in the same direction. That’s only six days away I do not rate this model much but almost a copy in GEFS it has been visible for quite some time. 

[Met4Cast]

Just now, Daniel* said:

Could this be one of those rare 12z suites where everything flips in the same direction. That’s only six days away I do not rate this model much but almost a copy in GEFS it has been visible for quite some time. 

Is there any verification stats for it? I think it's quite new, this winter is the first I've seen it being rolled out and it's suddenly being rolled out as often as the other models, though I suspect the slightly earlier run time helps with that

[tight isobar]

Now- worthy of note...ops 12z gfs..

Pc ridge begining to have implications for punch into the pole...as well as slowing of monentum..

The canadian large lobe-vortex expanse and drop off -migrate- are notable of trop response as the ssw effects are felt..

Cross polar switching looks steadfast for vortex seperation..

As the 10 hpa notes!!!..

Finaly the ops getting the mindset of there ensembles and supporting...

Expect some breathtaking synops..from here on in !!!

Edited February 14, 2018 by tight isobar

[Deep Snow please]

1 minute ago, Daniel* said:

Could this be one of those rare 12z suites where everything flips in the same direction. That’s only six days away I do not rate this model much but almost a copy in GEFS it has been visible for quite some time. 

It could indeed be one of those 12z suites, suppose we just need to wait for the other models to come out. As mentioned previously the ICON is mainly rolled out because it's out first, but six days is a massive improvement if it becomes a trend.

[The Eagle]

It's not new. It's an upgraded version of the old GME model.

[Met4Cast]

1 minute ago, The Eagle said:

It's not new. It's an upgraded version of the old GME model.

Ah righto, king of cannon fodder then! 

GFS does now need to live up to expectations though, the ICON was a pretty decent start to the 12z runs.

[AWD]

The UK widely settled and frosty at night to start next week according to the UKMO 12z;

Edited February 14, 2018 by AWD