Model output discussion - proper cold spell inbound?

[Nick F]

Yep, a strong jet stream over the Atlantic for next 7-10 days, driven by intense trop vortex to the NW, but it hits a brick wall of a block over NE Europe and Wern Russia. General theme continues from GFS op and GEFS for the trop PV to retrograde into northern Canada, allowing heights to rise to our N as well as NE from around the 18th feb.

With lag effect of MJO phase 7 at large amplitude and phase 8 + SSW downwelling, it seems hard to believe there won't be some high latitude blocking later this month ... just need patience until the high res runs latch on to the idea.

[BLAST FROM THE PAST]

2 hours ago, bluearmy said:

Given their better resolution in the strat - yes. Weak neg AO on this suite at odds with the gefs and geps. I think tomorrow morning’s run will be viewed with interest in Exeter, assumig the clusters don’t reveal anything obvious.

18z shows the concern nicely

 

BFTP

[Catacol]

The 4 GFS op runs today for early on Monday 19th. For me only one feature worth pointing out at this extreme range - strength of the scandy ridge originating out of Russia rather than the azores. On each successive run getting stronger as GFS output gradually gets a better grip of the swift impact of the vortex split.

Conditions over the UK different on each run (it is miles out after all) - but the trend is for that Scandy block to emerge. This is going to pool some very cold air in just the right place.... and as the trop pattern responds further to the combined weight of vortex annihilation and MJO forcing we end up with a biting reverse pattern - easterlies tapping into the cold pool over Russia with low pressure meandering around  underneath.

With a split like this (70hpa - but you could pretty much take your pick of the pattern at any height) the atlantic is doomed.

 

With a reversal forecast to move beyond 2SD at 65N we really cant expect very much else to occur. 30 - 40m/s the wrong way for several days? Bonkers.

 

 

[Banbury]

2 minutes ago, BLAST FROM THE PAST said:

18z shows the concern nicely

 

BFTP

How does it ??? The run hasn't finished 

[Catacol]

2 minutes ago, Banbury said:

How does it ??? The run hasn't finished 

It doesnt. The block is slightly delayed but the outcome is the same. Atlantic shutdown.

[Duane S.]

6 minutes ago, BLAST FROM THE PAST said:

18z shows the concern nicely

 

BFTP

What concern? The concern is we get unlucky, simple as that. Waste of time fretting about it this far out.

[ZK099]

People are calling the cold spell (which hasn't even started yet) dead already hahaha. This forum really doesn't fail to amaze me at times. 

The SSW HASN'T HAPPENED YET. Wait until it happens, and then talk about extended EPS. The way some of you talk about model runs you'd think they're right every time. 

In the last few runs, in terms of GFS, we've had Greenland highs, Scandinavian highs and Arctic highs. That's the sort of theme we need to continue. 

[ITSY]

Got to be honest, slightly disappointing postage stamps this evening, was hoping for more distinct signs of N Atlantic or Scandinavia Blocking. That said, still incredibly early days and we are only looking for trends at this point. The real action is still probably the best part of two weeks away, so no need to fret any time soon. Just part of the journey...

[MP-R]

Looking through the models and it looks like a slightly more active version of February 2006 - mostly chilly, not a lot of snow around, with a short Atlantic period around midmonth. Dates are very similar too. The easterly was pretty rubbish but the northerlies that followed were good.

   

Slightly different things at play this time, must be said, e.g. the Atlantic being much much more active than it should be at this time of year (essentially what has killed this current cold spell), but in terms of conditions felt on the ground, plenty of wintry weather on offer in one way or another over the foreseeable future with mild days like Thursday being very much at a premium. 

Wintry showers possible away from usual locations on Sunday:

 

A good week away I know but I'm also wondering if gales could be on the menu for Valentines Day. 

Lots to keep an eye on and I'm interested in this SSW. Still lots to be learned about them and hopefully one won't delay spring too much.

[Sneachtastorm]

Does an SSW ever lead to a Northerly flow for example Greenland high or is it always an Easterly if we manage to get lucky from it? 

[georgiedre]

6 minutes ago, Sneachtastorm said:

Does an SSW ever lead to a Northerly flow for example Greenland high or is it always an Easterly if we manage to get lucky from it? 

Wasn't 2010 northerly¿?

[Sneachtastorm]

Just now, georgiedre said:

Wasn't 2010 northerly¿?

Second part of it was yes, the one in mid to late December but I couldn't tell you if there was an SSW that year ha. 

[BLAST FROM THE PAST]

1 hour ago, s4lancia said:

What concern? The concern is we get unlucky, simple as that. Waste of time fretting about it this far out.

No fretting, I just think the Nirvana May be thwarted.  Just the way the winter rhythm has been.  Not unlucky...nowt to do with luck

 

BFTP

[BLAST FROM THE PAST]

1 hour ago, Banbury said:

How does it ??? The run hasn't finished 

It had on meteociel when I posted and block is not in correct place.   It’s an observation and also a POV re methodology......just re Feb......March is another matter.  Chances are very very much there....but they also aren’t too

 

BFTP

Edited February 7, 2018 by BLAST FROM THE PAST

[ICE COLD]

Another good FI on the GFS 00z ?

 

Edited February 7, 2018 by ICE COLD

[ICE COLD]

In fact it turns into a stonking run ?. @Frosty. I have nicked your lime light posting all the cold charts  this morning ?. 

[Ali1977]

If this GFS FI came into fruition the country would be in shut down, this would be a severe event up there with some of the best winter periods. Heavy drifting snow and ice days, and severe frosts at night....Long way out but things are on track for some proper winter cold that’s for sure 

[ICE COLD]

1 minute ago, Ali1977 said:

If this GFS FI came into fruition the country would be in shut down, this would be a severe event up there with some of the best winter periods. Heavy drifting snow and ice days, and severe frosts at night....Long way out but things are on track for some proper winter cold that’s for sure 

Morning Ali 

yep that's around 5 GFS rus now showing easterlies in FI . I no they all variy in where the block sets up . But as you say looking good ?.

ps - another one for @Frosty. ?

[Ali1977]

Some great ENS, but equally not all following the Op in FI. There are a handful that bring the block in earlier than the Op, P1 as an example has us in the freezer by the 17th but with little support - by the 19th around 7 ENS have a similar theme however. 

[Mucka]

Still awaiting a coherent cold spell signal but the ensembles are slowly trending colder again in FI

[Duane S.]

5 hours ago, BLAST FROM THE PAST said:

No fretting, I just think the Nirvana May be thwarted.  Just the way the winter rhythm has been.  Not unlucky...nowt to do with luck

 

BFTP

OK maybe luck is the wrong word in terms of what occurs will of course have happened for a reason. But what I meant is that there is surely going to be an element of ‘scatter’ after the SSW has occurred with the breakup of the tropospheric vortex. That is the wild card here and could make or break it for us IMO.

Edited February 7, 2018 by s4lancia

[That ECM]

Fully understand why people are looking out into fi. However the nearer time still has interest for some parts of the uk. T144 and those in the nw etc will be cheering on the ecm. More of a nw flow and not without a chance of snow. Worth a glance before searching for the beast if the ssw wasn't coming there would be much analysis around this time frame. 

[Banbury]

6 hours ago, BLAST FROM THE PAST said:

It had on meteociel when I posted and block is not in correct place.   It’s an observation and also a POV re methodology......just re Feb......March is another matter.  Chances are very very much there....but they also aren’t too

 

BFTP

Erm sorry  but it hadn't - the OP had, granted ,but the control and P1-P20 were only out to 156hrs , a bit foolish if you are commenting without seeing the Ens, many on here and TWO fall into that trap. Anyway history now, blocking still very much shown

[Mucka]

@That ECM

Funny enough I just popped in to reiterate my belief that we could see a decent snow event between the 12th and 13th due to embedded trough/s in very cold Westerly flow.

ECM 120 clearly shows incoming to far NW of Ireland with kinks in the flow already over central Britain

Also the Euros finally sniffing out the need to disrupt the trough SE - GFS still struggling a little with this.

Below is ECM/GFS 144 comparison to show how GFSs till wants to force far too much energy NE by comparison so for me the Euros are leading the way this morning though with more favourable corrections to come

 

Edited February 7, 2018 by Mucka

[That ECM]

I might be talking rubbish here(I like to fit in) only joking but is this the ecm starting to model the ssw? Split pv with heights over the artic. Chino, I may have misinterpreted, said after the initial event was looking for a second to damage what would be sat over Hudson Bay Area. 

 

Constructive comments would be appreciated.