The hunt for cold - Model discussion (late November)

[Scandinavian High.]

Well looking at ukmo high pressure to north east looks like putting up a fight with low pressure going south east in to Europe John Hammond also saying block could be stronger next week I’m going say gfs ecm will fall in line later with scandi high flexing its muscles..

[shaky]

8 minutes ago, abbie123 said:

Well looking at ukmo high pressure to north east looks like putting up a fight with low pressure going south east in to Europe John Hammond also saying block could be stronger next week I’m going say gfs ecm will fall in line later with scandi high flexing its muscles..

Lets where the 06z gfs takes us then!you would think if the scandi high is gona start flexing its muscles it needs to do it on the gfs 06z or on the evening run!

[booferking]

There she is the great uk hurricane of 2018..

[swfc]

HMMM.Low further south on the gfs 6z.mayby know real change after but still ?

[Midlander]

8 minutes ago, booferking said:

There she is the great uk hurricane of 2018..

That looks amazing!

[kumquat]

28 minutes ago, abbie123 said:

Well looking at ukmo high pressure to north east looks like putting up a fight with low pressure going south east in to Europe John Hammond also saying block could be stronger next week I’m going say gfs ecm will fall in line later with scandi high flexing its muscles..

Agreed. Things at 6 days away still not sorted out. Scandi block could be more robust than some iterations are showing.

UKMO 144

GFS 6z

ECM 0Z 144

It's a fine line still and not irreversible at this stage.

Await the 6Z para.

[Guest]

8 minutes ago, AppleUK 123 said:

That looks amazing!

I think the focus of the next 10days needs to be on identifying the details on what could be a potential severe and damaging spell of weather opposed to the white stuff which unfortunately looks only looks transitionary even for only the highest parts of the UK. 

[edinburgh_1992]

16 minutes ago, AppleUK 123 said:

That looks amazing!

Amazingly mild. T850s rising with every run. The average for Edinburgh is about -3 for December, not +3. Seems to cool off afterwards though. Also, I think that low will shrink a lot nearer the time, if it even passes over the UK. 

Edited December 7, 2018 by edinburgh_1992

[The Beast From The East]

On 20/11/2018 at 18:04, Roger J Smith said:

I don't expect too much to happen before mid-December, very strong cold outflow into eastern North America this week will tend to put too much southward pressure on the jet stream in the western Atlantic to prevent a milder pattern from re-establishing in western Europe for a couple of weeks probably, after which I think a stronger blocking high is likely to develop and another retrograde episode this time drawing on more potent cold than the current easterly has to work with. Probably some really good winter synoptics eventually, patience advised though. Dec 19 to 24 period will be volatile and may feature a winter storm for at least some parts of the UK and Ireland, possibly a battleground scenario. Much colder to follow that. 

Hi Roger, love reading  your post on here. Going back to your above post from back at the end of November, do you still have the same view on how you think December will turn out? Is it still looking on track to you? Looking at the models we seem to be looking at the Atlantic in control for a while yet sadly. Just hope we eventually get a strong enough block in the correct place to bring us what most of us crave ?☺❄

Many Thanks Roger.

[swfc]

5 minutes ago, edinburgh_1992 said:

Amazingly mild. T850s rising with every run. The average for Edinburgh is about -3 for December, not +3

-3 AVERAGE IN DECEMBER????

[Weathizard]

As an aside note from the chase for cold (not that there is much right now) this is a worrying chart for parts, after 2 weeks of saturating weather this could be really nasty

Looks like a period of atlantic domination for the time being, the worst possible outcome for me!! Can’t stand this weather.

[feb1991blizzard]

INSTANT TROP RESPONSE ALERT!

Edited December 7, 2018 by feb1991blizzard

[Paul_1978]

The above update from Knocker in the other thread suggests that the EC46 isn't as good as was suggested in here yesterday evening. However I suspect we are talking about different timescales within the 46? 

(Ignore the last sentence - I think he's feeling lonely).

[bluearmy]

11 minutes ago, feb1991blizzard said:

INSTANT TROP RESPONSE ALERT!

Have you looked at the heights rather than the temps?  

At 50 and 10hpa

  

Edited December 7, 2018 by bluearmy

[feb1991blizzard]

2 minutes ago, bluearmy said:

Have you looked at the heights rather than the temps?  

Yes.

https://www.instantweathermaps.com/GFS-php/strat.php?run=2018120706&var=HGT&lev=10mb&hour=276

[feb1991blizzard]

8 minutes ago, bluearmy said:

Have you looked at the heights rather than the temps?  

At 50 and 10hpa

  

Sorry yes - it has nothing to do with the upper warming

Edited December 7, 2018 by feb1991blizzard

[Singularity]

Ironically, stronger stress on the vortex than previously modelled has as a by-product increased the modelled stretching across the N. Atlantic next week, likely giving the N. Atlantic troughs an extra boost just when we really didn't want to see that. 

While model bias still suggests that the W. Eurasian blocking should prove more resilient than currently modelled, I'm sadly getting the impression that the cold boundary will end up hanging around just out of reach to our east. Could be only some 750 miles in it.

The big flip-side is of course that the stronger disruption of the vortex is tied in with increased SSW probability for late Dec or early Jan. How much correction toward less Atlantic mobility we see next week will be important for whether we can achieve that from our very encouraging, but not guaranteeing standpoint; more fight back from the blocking will further increase troposphere-stratosphere transport and hence the magnitude of warming + geopotential height rises int he stratosphere.

[bluearmy]

6 minutes ago, feb1991blizzard said:

Sorry yes - it has nothing to do with the upper warming

There remains a disconnect of sorts between the upper vortex and the trop - would be good to see the upper vortex imprinted solidly on the trop !  Looking at the upper strat pattern, Hopefully just a matter of time before it is ..........

[MP-R]

One advantage I can see is that temperatures do look like 'predominantly' returning to and staying at average next week, which will be a welcome change to the tropical tripe we've had this week.

That of course is tied in with the jet slipping south and us ending up in 'the wet zone' as I like to call it ie no longer in the hairdryer but neither benefitting from December 2017 style NWerlies. I am concerned by the risk of more widespread flooding as time goes on. Are we perhaps seeing November 2009 all over again but a few weeks later? Would certainly fit with a transition to seasonality towards the latter part of the month.

Edited December 7, 2018 by MP-R

[winterof79]

I have gleaned  enough information via this thread and other sources to hop off my hastily built fence for another memorable winter to unfold.

Major warming around exmas now odds on starting to show on the NWP,and we will be deep into winter as it downwells. A RTR most welcome

Posted this in media thread too from John Hammond

MONDAY 24TH DECEMBER – SUNDAY 6TH JANUARY

Signs of major change

There are signs of more severe cold as we head into the New Year

You’ll have inferred, then, that I am not yet going to commit: Green or White Christmas? It’s simply too far off!

However, there are several reasons within the set-up of the atmosphere this winter that suggest the cold air will be back sooner rather than later. El Nino is one; the cycle of spots on the sun is another even more distant influencer.

Additionally, in the last few weeks I’ve spoken of signs that the usually strong stratospheric westerly winds that circle the Arctic (know as the Polar Vortex) may weaken markedly as December ends. This signal is becoming more ominous. It’s important because it introduces the possibility of a ‘Sudden Stratospheric Warming’ in which the Polar Vortex goes fully into reverse. Ultimately, it was this which led to the severely cold spell that struck the UK late last winter.

From start to finish, this process takes several days, if not weeks, before such a reversal works its way down to ground level. But on balance, there is an increasing chance that cold air will return from the north or the east as we go later through the Christmas period, and more particularly into the New Year.

Exciting times ahead – for the child and the weather enthusiast in all of us! 

 

EDIT

Apologies to Summer Sun didny see you had posted same.

Edited December 7, 2018 by winterof79

[shaky]

Gfs para interesting!!low disrupting more at 144 hours and further south!!

[feb1991blizzard]

20 minutes ago, winterof79 said:

 

Green christmas and very white new year for me.

[winterof79]

7 minutes ago, feb1991blizzard said:

Green christmas and very white new year for me.

Yes with possible surprises for some as the jet relaxes s/e

[phil nw.]

2 hours ago, bluearmy said:

In the past, when ukmo picks the different route at day 6 against the others, you tend to see the others cotton pretty well straight  away - I expect the ukmo to go with the ecm on the 12z run 

struggling to maintain enthusiasm to stay in this thread .... could be off to knockers ...

You would be very welcome Blue, the more the merrier.

[Frosty.]

I would much rather see cold zonality that the extended Ecm 00z ensemble mean shows than mild benign or sw'ly zephyrs cr*p..