Model output discussion - proper cold spell inbound?

[bluearmy]

7 minutes ago, That ECM said:

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.

Constructive comment - ‘yes, it is’ 

note the purples turning blue by day 10 and the general high slp over the eurAsian side of the NH 

[Met4Cast]

I don't think i've ever seen the GFS be so consistent run to run in the deepest FI as it has been over the last 3-4 runs, quite incredible really.

[That ECM]

1 minute ago, bluearmy said:

Constructive comment - ‘yes, it is’ 

note the purples turning blue by day 10 and the general high slp over the eurAsian side of the NH 

Does that mean nick has won the virtual beer

 

definitely been a trend for heights to build over the areas you mention. 

[Decemberof2010]

4 minutes ago, Daniel Smith said:

I don't think i've ever seen the GFS be so consistent run to run in the deepest FI as it has been over the last 3-4 runs, quite incredible really.

Yes Daniel quite true. We often get wintry nirvana from GFS. However it does keep the theme in fi over the last few days. Add to the fact the MO lrf has had the same wording for a few days too, does give hope!

Lookinh forward to the model runs coming up over the next few days. 

Is the ECM now starting to show interest too?

[bluearmy]

14 minutes ago, That ECM said:

Does that mean nick has won the virtual beer

 

definitely been a trend for heights to build over the areas you mention. 

Not really - we were talking at crossed purposes. I thought he was expecting the ops to flip to deep cold before next weekend 

[bluearmy]

32 minutes ago, Daniel Smith said:

I don't think i've ever seen the GFS be so consistent run to run in the deepest FI as it has been over the last 3-4 runs, quite incredible really.

One run wasn’t scandi ridge ???  A qtr has occurred every run for the past 4 now though !! The best cod spells count down like clockwork ..........

Edited February 7, 2018 by bluearmy

[BLAST FROM THE PAST]

1 hour ago, s4lancia said:

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.

Indeed and fair enough. 00z GFS drops right with the blocking.  Troposphere disruption is going to happen but just injecting lots of caution which is unusual for me 

This is where I’m at....my 12 year old is desperate for a good dumping of snow

 

Posted 22 hours ago (edited)

Certainly will be interesting but GFS 00z displays my ‘concerns’ well.  Block not in right place to bring ‘the cold blast’ .....not in Feb anyway.  Still we await the effects of the SSW.

From Midmonth target period, deep LP system attacking on WNW/ESE flow, then effect of building HP to E/NE forcing on trough either stalling it in place or hopefully forcing undercutting.

 

BFTP

 

 

Edited February 7, 2018 by BLAST FROM THE PAST

[winterof79]

1 hour ago, s4lancia said:

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.

My limited understanding of the effects of a SSW are that we get a wind/jet stream reversal. Therefore it makes perfect sense for a build of pressure to our NE.

http://www.bbc.co.uk/weather/feeds/20992173

[Duane S.]

ECM D10 looks more the part at last. Ripe for amplification in behind that breakaway trough.

[bluearmy]

Eps anomolous run from yesterday dropped 

back on script as heights lower to our south 

[Duane S.]

4 minutes ago, winterof79 said:

My limited understanding of the effects of a SSW are that we get a wind/jet stream reversal. Therefore it makes perfect sense for a build of pressure to our NE.

http://www.bbc.co.uk/weather/feeds/20992173

Yes, absolutely, a build of heights to the NE is indeed the most likely route om paper but it may (or may not) be that straight forward (mind you, when ever is it!?).

I am a firm believer though that this is going produce. We just may have to wait a little longer if the trough displacement isn't favourable initially.

 

[BLAST FROM THE PAST]

10 minutes ago, bluearmy said:

Eps anomolous run from yesterday dropped 

back on script as heights lower to our south 

Good news, long may that continue and come into reliable

 

BFTP

[mb018538]

Yes, ECM certainly looks more on the money today. Arctic high building, deep trough weakening....full steam ahead!

[TEITS]

30 minutes ago, BLAST FROM THE PAST said:

Indeed and fair enough. 00z GFS drops right with the blocking.  Troposphere disruption is going to happen but just injecting lots of caution which is unusual for me 

This is where I’m at....my 12 year old is desperate for a good dumping of snow

 

 

 

Always wise to be cautious Fred.

For me it is clear extensive blocking to our NW/N/NE is going to develop from around the 19th. However as we all know this still does not guarantee cold for the UK. Take for example the 0Z GFS. It would only require a slight change in orientation for the source of the E,ly to come from the SE rather than the E. The same applies to a Greenland HP if the block is too far W and we end up with S,lys instead of N,lys.

Still on a positive note we have much to look forward to and what I describe above is only if we get very unlucky. Nobody yet knows where the block will develop but the GFS has been very consistent in developing N blocking and we should at least experience the cold when the arctic floodgates are opened.

[bluearmy]

Following on from Dave’s post, the eps control deveiops extensive n blocking and w euro trough but eventually  brings a warm easterly (remember jan)

the eps do show e euro high uppers anomoly through the extended period 

I don’t believe that the ens means have yet found a qtr although individual members and clusters will. I’m sure they will !

[nick sussex]

For those that are now bored of chasing easterlies look away now!

At least initially something from the ne or east would be the likely evolution because as the PV heads nw that opens the door to pressure rises there.

If we’re to see a sustained spell of cold you northerly fans should also be happy as that’s the natural progression you see in any longer UK cold spell.

However we’re still some way from any initial cold and a few hurdles to jump before then.

 

[snowfish1]

Ooh u tease Nick Sussex 

[Catacol]

I am becoming a bit worried.... because I'm turning into a GFS op junkie. How is this possible? We all know GFS FI is there to be snorted at... but right at the moment I cant help it.

All 4 runs yesterday progged blocking for week beginning 19th Feb. 3 mainly over Scandy... 1 that had a distinct Greenie flavour.

No change this morning. GFS of early Monday 19 once again showing the pronounced scandy block.

Not interested in details - only in trends. 5 out of 5 since starting this FI block hunt. This is all the result of the vortex split and SSW reinforced by a favourable pacific pattern. The predictability of op runs at the moment is a reflection of the consistency of the teleconnective signal.

And this pattern is likely to build rather than fade. To something like this FI image this morning....... block and reversed undercut. Crikey...

[tight isobar]

16 minutes ago, nick sussex said:

For those that are now bored of chasing easterlies look away now!

At least initially something from the ne or east would be the likely evolution because as the PV heads nw that opens the door to pressure rises there.

If we’re to see a sustained spell of cold you northerly fans should also be happy as that’s the natural progression you see in any longer UK cold spell.

However we’re still some way from any initial cold and a few hurdles to jump before then.

 

The easterly/north easterly type looks favoured(via ssw route)..

However i hope we don't entail-the same hurdles getting over, as some of my picked horses on lucky 15's of late..

Or we are not-on the money but very quickly losing it!!?...

Over to the 6z suite for evolutions.

[Summer Sun]

UKMO extended looks very unsettled with the risk of Gales possibly severe in places

[nick sussex]

13 minutes ago, snowfish1 said:

Ooh u tease Nick Sussex 

I’m saying nothing ! 

Ok then I will! 

Generally in set ups with higher latitude blocking signaled , if the UK is lucky then you do get a repeat scenario developing which alternates between east ne and then northerly . So Scandi high retrogresses you then get a trough dropping south into Scandi which develops a more northerly and then back to an east ne and repeat.

It would be great to see that happen but we haven’t even got to the Scandi high bit yet and it’s some way off.

[Roadrunner]

Was there a SSW prior to February '91? May have been answered previously so apologies if so. I also remember around the time we had the snow nirvana that year, the Eastern seaboard of the USA had quite high temperatures for the time of year. May mean nothing at all - then again my knowledge is very limited! 

[Scandinavian High.]

This is way out but if that came of there would be blizzards up down the uk interesting that meto are going with chance of very cold weather easterly winds later part of Feb we could be heading for a uk freeze up...

[Barry Reynolds]

27 minutes ago, Roadrunner said:

Was there a SSW prior to February '91? May have been answered previously so apologies if so. I also remember around the time we had the snow nirvana that year, the Eastern seaboard of the USA had quite high temperatures for the time of year. May mean nothing at all - then again my knowledge is very limited! 

Yes, apparently so, as Judah Cohen was comparing similarities with the split vortex then, to the forthcoming one. He mentioned it on Twitter.

Edited February 7, 2018 by Barry Reynolds

[Johnp]

56 minutes ago, bluearmy said:

Following on from Dave’s post, the eps control deveiops extensive n blocking and w euro trough but eventually  brings a warm easterly (remember jan)

the eps do show e euro high uppers anomoly through the extended period 

I don’t believe that the ens means have yet found a qtr although individual members and clusters will. I’m sure they will !

Didn't you say low heights to our south on eps a couple of hours ago? Now you mention a euro high?

Apologies if I'm getting confused.