Model Output Discussion - 05/01/2016 18z onwards

[Captain Shortwave]

Well apart from a brief less cold blip where low pressure rides over the Atlantic ridge the GFS is cold and potentially snowy all the way to the end with a monster Euro/Scandi trough developing in low resolution.

Still a long way to go and questions about whether we can build a high latitude block in a region favourable for us is going to be a big debate.

If we can get the day 6/7 charts currently on offer I suspect a toppler would be very hard to achieve with strong positive heights to our west and strongly negative ones to our east/south east.

So addressing the high latitude block;

The GFS has toyed with the Greenland high over the past couple of runs with varying success, the 06z achieved this but sucked it away leaving a west based -NAO, ironically the failure on the 12z actually delivers a colder run with the Atlantic ridge still in place even at day 16.

Low resolution

 

This fits reasonably well with the current ens guidance with the pattern remaining similar throughout.

The GEM is fairly similar to the GFS to day 10, a faster development of the cold pattern (Close to the UKMO, but a faster transition to a brief more settled and less cold spell at day 10).

So that leaves the UKMO

Now this certainly catches my eye, more else but for the potential to develop a high latitude block east of Greenland (potentially aligned between Iceland and Svalbard). So a block directly north of the UK with a deep cut off trough over Europe with winds east of north, certainly more so than the GFS/GEM solutions this afternoon.

A lot of interest and some serious potential beyond 4/5 days away when the current Atlantic trough clears eastwards and allow polar maritime and eventually an Arctic maritime airmass to sink across the UK.

Edited January 6, 2016 by Captain Shortwave

[Bullseye]

Few US guys mentioning about how the negative NAO in mid/long range is nothing like past 2 winters (which where brutal in US) but more of a tradition NAO, does this mean more central or east based like what GP was referring to last night. Going by tonight's runs we seem to be heading towards a negative anyway.

[Frosty.]

Absolutely sensational Gfs 12z with a double whammy of wintry weather. Next week shows a genuine nationwide cold spell with increasing chance of snow showers and ice with widespread frosts and then there is the mother of all reloads. I've been waiting all winter so far to cut loose with my limitless enthusiasm for wintry weather and it looks like the majority of us who are coldies, are in for a treat next week and hopefully further ahead too!!!Boom

Edited January 6, 2016 by Frosty.

[phil nw.]

1 minute ago, Harsh Climate said:

As great as this run is it offers little snow for 90-95% of the country! With coastal areas/northern scotland/northern ireland getting a pasting. 

 

What's great about this run is the potential and how it may develop though.

Yes i think that's the best way to look at it.

The main point is the cold starts to land in Scotland around 11/12th and nationwide by 13th with uppers circa -5 to -8c up north.If anything UKMO a little quicker with that.

Plenty of disturbances around the upper trough just to our east by then along with possible channel runner as Captain S mentioned earlier.

A decent run by GFS with the cold never really lifting.

 

[mountain shadow]

8 hours ago, craigore said:

Just need the ECM op to join the party.

[Yarmy]

4 minutes ago, Ravelin said:

Nor sure exactly where it starts to diverge (at work, so awkward to full-screen the charts to compare runs), but I'm not sure the 12Z in the middle stages bears much resemblance to the 06Z, never mind the latter stages.

Undoubtedly, and to be honest I think we're still a fair way from a done deal (as far as cold longevity goes). The storm that spins up off the coast of Canada at T174 was there on the 6z and it helps to reinvigorate the WAA into Greenland. But as ever it's timing, alignment, shortwaves, etc, etc. So many moving parts. Who knows?

[radiohead]

Excellent T144 GEFS mean

 

[feb1991blizzard]

14 minutes ago, Harsh Climate said:

As great as this run is it offers little snow for 90-95% of the country! With coastal areas/northern scotland/northern ireland getting a pasting. 

 

What's great about this run is the potential and how it may develop though.

Don't worry, this setup is ripe for polar lows to form and unexpected shortwaves to develop.

[fat chad]

3 minutes ago, feb1991blizzard said:

Don't worry, this setup is ripe for polar lows to form and unexpected shortwaves to develop.

True polar lows are extremely rare..so I have been told on here.

[Hotspur62]

Just got in from work and wow ha a GFS !!.However, what is more positive is that a good cold trend is developing from the Models now in the semi reliable timeframe. Not popping the champagne corks yet as I have seen things go TU on mny occasions but think I might enjoy a nice glass of chilled Sav blanc this evening.

Coldies have waited 2 years for these synoptics and hope the weather gods play ball now !!  

[Mucka]

GFS ensemble summary out to 168

Rock solid support now for Atlantic ridge reaching into Greenland.

Most are a little more reluctant than UKMO to clear the trough East so quickly and so GFS overall still wants to delay the start of the cold by 24/48h by comparison.

One or two show potential for Icelandic or West based spoiler shortwave to develop which would cut off the cold Northerly flow for a while but these are very much in the minority - not worth the worry unless it gathers pace.

Not worth looking at potential snowfall at the moment other than in a genralised form IMO as too far out and anyway GFS ppn charts are notoriously dodgy even in the near timeframes. Let's just get the cold air over us first and in that respect things are looking very good.

Edited January 6, 2016 by Mucka

[Methuselah]

Just now, fat chad said:

True polar lows are extremely rare..so I have been told on here.

The last one I can recall, was in February 1969: from light graupel with no wind, at 2C, to driving snow at -5C, all within about 30 minutes. I think that the pattern then was very similar to what the GFS is suggesting...Here's hoping!

[Mapantz]

22 minutes ago, Harsh Climate said:

As great as this run is it offers little snow for 90-95% of the country! 

 

22 minutes ago, SLEETY said:

fair bit of snow for most the country from this gfs run

[Polar Maritime]

Fantastic GFS again tonight with even stronger heights over Greenland/Poles, With re-load potential.  All about the detail now.. 

 

 

Edited January 6, 2016 by Polar Maritime

[feb1991blizzard]

2 minutes ago, fat chad said:

True polar lows are extremely rare..so I have been told on here.

They are but if any setup could deliver one, its this, you can see the isobars curving and wave type features, its not your straight isobar, wishbone type Northerly, I thing polar lows form to the NW - NNW of british isles, I think it depends on exactly how cold it gets way above 850mb though.

[Zerouali lives]

For me the 12z GFS is the best run since late Feb/early March 2006 - we could be looking at around 10" / 12 " of snow by next weekend

Edited January 6, 2016 by Zerouali lives

[ALL ABOARD]

 

GFS also gives us this towards the end of the run? 

Major strat warming there!!!!!!

 

This is for around the 22nd of January.. cards are starting to fall into the 'cold' category.

 

Edited January 6, 2016 by ALL ABOARD

[bluearmy]

Mucka - I wouldn't be looking for shortwave spoilers on the ens 

they are far more likely to appear on ops and the few that show up on ens members are less likely to verify

they are only there to keep you on edge !

 

 

[Southender]

We are now starting to be shown a bit of consistency in the output. Different variations, but on the whole much colder and certainly the best chance of nationwide wintry weather this winter. We now need to see this theme maintained for the next few days. Specifics I don't care about, we can nail that down nearer the time. What I don't want to see is any of the models starting to abandon ship now. We have seen it loads of times in winters past, so I for one will not be dusting off the sledge for a while yet. But, I think we can safely say it will be more "seasonal" as we go through next week. About bloody time as well.

[Nouska]

24 minutes ago, Stormeh said:

What a great 12z from the GFS!

Does anyone know if it's possible for polar lows to form in this kind of setup? thanks.

Polar lows ideally require 500mb temps to be -40C or colder for formation - ideal set up shown on the GFS 12Z run. Earlier part is more on the west coast but look at this moving down the North sea in the low-res section.

All subject to change but a long time since such potential seen.

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=13&ech=204#

Edited January 6, 2016 by Nouska

[East_England_Stormchaser91]

12z is a stonker I must say. Pretty much all of Europe and UK going into the freezer with brutal cold on stand by to tap into. 

The extent south of the cold is mind boggling too, with even morocco seeing a potential snow event, especially over the Atlas Mountains! 

Edited January 6, 2016 by East_England_Stormchaser91

[Mark Neal.]

I reckon even Johm Hammomd took a look at the 12z GFS  

@bbcweather - Computer models very confident of much colder weather next week. Exactly when it arrives is another matter... John H

[Mucka]

6 minutes ago, bluearmy said:

Mucka - I wouldn't be looking for shortwave spoilers on the ens 

they are far more likely to appear on ops and the few that show up on ens members are less likely to verify

they are only there to keep you on edge !

 

 

Agreed but I was just giving a summary of what the ensembles show, I actually de-emphasised them in my post.

GFS short ensembles central England.

Cold programmed to be here from the 13th according to these.

Edited January 6, 2016 by Mucka

[Methuselah]

26 minutes ago, knocker said:

Is it operable?

Not sure about 'operable' knocks, but I might need a bottle of Russian Standard to help me prepare for the 18Z; which, the way things seem to be headed, could be even more stonking!

Edited January 6, 2016 by Ed Stone

[karlos1983]

Well I will be book marking that GFS run. I don't think I can say ever seen a run quite like it. Jaw droppingly amazing. I'm very mindful that it's almost impossible surely to get a run now that can top that. So I'm managing my expectations before the ECM rolls out, and really looking at the theme rather than trying to replicate the GFS, because I can't honestly see that happening. But believe me I live in hope. 

As for snow chances comments I've seen, I wouldn't rule out snow pretty much anywhere in the uk going on the GFS, how anyone can is beyond me, I just hope we get the chance to worry about that nearer the time. One thing today has shown is that it is absolutely a possibility that it could play out like that. 

I'm off for a lie down, just WOW!