Model output discussion - 5th December 2016 - Into Winter we go

[mulzy]

Truly dreadful NWP output this evening - no point sugar-coating it.  The ECM ensemble day 10 mean chart below encapsulates our pretty dire outlook (as far as coldies are concerned).

Edited December 5, 2016 by mulzy

[nick sussex]

ECM short ensembles. Op run was a cold outlier!!! lol

Okay sorry for that. Although there are a bigger cluster of milder solutions, its close to the mean, there are some colder solutions which have survived.

It looks like a 40/10 split with the minority possibly having the Euro high further north, possibly one or two bring in a Scandi high.

[Kentish Snowman in Yorks]

17 minutes ago, Steve Murr said:

So if you ever wanted a last depressing post & a totally different way of illustrating the possibility of snow here is the T2Ms for london in grid form for all the ensembles

from 20 runs - it takes all the way to timepoint 234 hours to see 1 run see a negative dewpoint of -0.3, & prior to 300 hours there are only 8 in incidence of a dewpoint lower than -1 ( from a choice of 20 runs x 21 timepoints )

so the very best would be 420 timepoints below -1, we have just 8 & (0 pre 228)

thats about 2% chance then...

look at the swathe of warmth through 7 days !

 

 

C'mon Steve you are supposed to be the Coldies Saviour!  Why let the truth get in the way of an obscure route to cold!  I am sure we can find one if we look hard enough?!

CANSIPS?  BOM?  NAVGEM?  Any model will do!!  Just start talking wintry to us!  

[Spah1]

2 minutes ago, mulzy said:

Truly dreadful NWP output this evening - no point sugar-coating it.  The ECM ensemble day 10 mean chart below encapsulates our pretty dire outlook (as far as coldies are concerned).

You're posting this while Matt is posting this. No wonder no-one knows what's going on. 

[blizzard81]

1 minute ago, nick sussex said:

ECM short ensembles. Op run was a cold outlier!!! lol

Okay sorry for that. Although there are a bigger cluster of milder solutions, its close to the mean, there are some colder solutions which have survived.

It looks like a 40/10 split with the minority possibly having the Euro high further north, possibly one or two bring in a Scandi high.

I know you are good on those wind directions Nick What do you think the control shows towards the end? It dives and goes opposite to the op.

[Summer Sun]

1 minute ago, Spah1 said:

You're posting this while Matt is posting this. No wonder no-one knows what's going on. 

 

That chart you've quote Matt on is what he posted last night

[nick sussex]

14 minutes ago, blizzard81 said:

I know you are good on those wind directions Nick What do you think the control shows towards the end? It dives and goes opposite to the op.

I'm waiting for the extended ones to come out which include the wind direction.

Not much cheer I'm afraid in the extended range, a few colder solutions but that could just be the normal scatter. Generally wind direction cluster is southeast  to west. Dew points give the game away, only a small cluster get below zero and they're probably the ones with the Euro high bringing in a more se flow.

Unless theres some miracle at around T144hrs then its looking underwhelming until at least mid month and probably a bit longer. I still wouldn't rule out a change over Christmas, that's too far ahead and one would hope that our luck might change by then!

Edited December 5, 2016 by nick sussex

[karlos1983]

Just now, Summer Sun said:

That chart you've quote Matt on is what he posted last night

Yes, Matt Gate is over with. Let's not start that again 

[booferking]

2 minutes ago, Summer Sun said:

That chart you've quote Matt on is what he posted last night

Okay but i think he meant this posted  3hrs ago.

[Ali1977]

4 minutes ago, Summer Sun said:

That chart you've quote Matt on is what he posted last night

Today's post

And im sure many, even thoughs who have given up on any cold in Dec will be intrigued to know what the EC46 says. 

Edited December 5, 2016 by Ali1977

[fergieweather]

1 minute ago, nick sussex said:

I'm waiting for the extended ones to come out which include the wind direction.

Vast majority of members between S to W by 20th. Two clusters in final phase of run (as per 00z). Flip-flopping continues between these two very equally balanced broad solutions.

[Faronstream]

Even when i look past 400 hours on GFS 12Z ( i know it's really far out) around christmas i still can't see any real cold or brutal cold christmas like 2010, and it was 4 years ago i had a white christmas. Well i think this year it will be a very average christmas year with temperatures close to average and that means slightly above 0 degrees in most of England and just slightly below 0 for the eastern parts of west europe

[Spah1]

6 minutes ago, mulzy said:

Truly dreadful NWP output this evening - no point sugar-coating it.  The ECM ensemble day 10 mean chart below encapsulates our pretty dire outlook (as far as coldies are concerned).

You're posting this while Matt is posting this. No wonder no-one knows what's going on. 

Agreed, I just thought it was quite relevant as a source of info compared to the one above clearly demonstrating the pattern is very mobile at the moment and the outlook is very uncertain. 

[blizzard81]

4 minutes ago, nick sussex said:

I'm waiting for the extended ones to come out which include the wind direction.

Silly me lol

[Ali1977]

3 minutes ago, fergieweather said:

Vast majority of members between S to W by 20th. Two clusters in final phase of run (as per 00z). Flip-flopping continues between these two very equally balanced broad solutions.

Mmmm, not looking too good for a swing is it - even though the image Matt posted actually looks great but doesn't paint the real picture I guess.

Edited December 5, 2016 by Ali1977

[Seasonality]

7 minutes ago, Spah1 said:

You're posting this while Matt is posting this. No wonder no-one knows what's going on. 

But Matt is a pro and Mulzy is just one of us forum members. No offence Mulzy, that includes rank amateurs like me too.

[Stuie]

@fergieweather Ian is that looking combined to HP over the UK?

[bobbydog]

2 minutes ago, fergieweather said:

Vast majority of members between S to W by 20th. Two clusters in final phase of run (as per 00z). Flip-flopping continues between these two very equally balanced broad solutions.

Hi Ian, you probably missed my earlier question in the melee but following your post earlier today, how is the GFS parallel performing compared to the operational?

[Ali1977]

De Bilt ENS not great, you would think if an Easterly was brewing any cold would be showing on their ENS before ours. 1 small cluster going for cold only looking at it, starting around day 10.

It does look like a cool down in general around the day 10 mark though.

Edited December 5, 2016 by Ali1977

[feb1991blizzard]

3 minutes ago, fergieweather said:

Vast majority of members between S to W by 20th. Two clusters in final phase of run (as per 00z). Flip-flopping continues between these two very equally balanced broad solutions.

Surely then cold (snowy) very very unlikely before xmas based on that suite?

[blizzard81]

2 minutes ago, feb1991blizzard said:

Surely then cold (snowy) very very unlikely before xmas based on that suite?

Sounds very much like that to me.

[Sweatyman]

1 hour ago, Allseasons-si said:

I hope it's something like this.....goodness me,Merry Christmas and a happy new year every one

run it through

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=354&mode=0&carte=0&run=10

it could happen

But it won't as we all know ..

[bluearmy]

A very underwhelming day of output unless you have faith in the GEFS to pick the way forward. The eps thrown out two runs which have trended away from anything other than faux cold and that looks less likely on these runs which have quite a positive NAO sig. there is a chance of diving troughs but that's the best I can manage and if we do see that, no convincing signs that a continental flow would be cold enough to make any sliders of interest. 

[Nick F]

26 minutes ago, Singularity said:

J. Cohen has in some of his recent blog posts pointed out that the models have a known bias toward blocking off positive height anomalies trying to propagate down from the stratosphere when actually they should make it through and influence the 500 mb pattern. This can explain the oversights by GFS, provided one assumes the parallel has been adjusted to reduce or even remove the aforementioned bias, but the wild swing by ECM this evening remains a conundrum. Weirdly, I can recall a few occasions past where ECM has unleashed a fury of hyper-mobile deterministic runs out of the blue and then, within a day or two, stowed them away again as suddenly as they appeared. Perhaps, at times when intense thermal gradients are occurring upstream of the UK, the higher resolution causes more in the way of a feedback effect from assumed overly-efficient baroclinic processes.

This is a suspicion I've harboured for some time now, but I've not attained enough evidence to state it as fact - and still haven't, I'm afraid! I've only bothered posting it in case we do end up with a far-less mobile outcome for next week, which would be quite revealing.

Regardless of the fallibility of the op runs, it's high time we had a decent one to look at and make us smile. All we can do is wait, hope, and try not to let the lack of quick gratification get to us 

Really is going take something not well-modelled by the ops to change the pattern more favourably, like you say warming/+ve heights working down from the stratosphere. 

However, the MJO for a while is not looking favourable for sustained trop  blocking in our locale, plus the upcoming deep and intense cold sweeping N America will only serve to stoke the fire of the PFJ downstream towards the U.K. Not really surprised the ops are churning out the mundane mobile Atlantic charts with unfavourable MJO, low AAM and slightly strengthening wQBO working against HLB ... for now.

maybe the EC46 will give some relief from the op monotony later.

[blizzard81]

11 minutes ago, Ali1977 said:

De Bilt ENS not great, you would think if an Easterly was brewing any cold would be showing on their ENS before ours. 1 small cluster going for cold only looking at it, starting around day 10.

It does look like a cool down in general around the day 10 mark though.

There is a bigger cluster of cold runs at days 11 and 12 when compared to the 00z suite. That grouping then stays quite strong right to the end. I guess they are easterlies.