Model Output Discussion 18th Nov.2013-12z onwards.

[Barry12]

The next northerly chase is on then! it'll get down to 96 hours again and then a shortwave will pop in to say hi and ruin everything, but I'd rather it show a northerly at 240 hours than a south westerly.

Edited November 20, 2013 by Barry95

[DAVID SNOW]

Kinda of a nomans land moving forward with a mid Atlantic high and low pressure across SE Europe.

 

We desperately need some amplification upstream and its game on for a Northerly,the problem is that strong jet raging to the north.

Blimey Happy Days I don't think we "desperately need" any pattern to evolve right now, the last time I looked its still Autumn  and rather cold too

[Matty M]

ECMWF OP definitely in the milder end of the ensembles after day 6

[Catacol]

ECM for 30 Nov bears a passing similarity to a pattern picked up by GFS at long range a few days ago. I mentioned at the time that GFS has a habit of occasionally picking up on a pattern before dropping it and then finding it again. Here was GFS for 1st Dec in FI a few days ago just at the time with the wave 2 warming was picked up in the strat for 10 days ahead:

 

 

 

And here is ECM for 30 Nov today:

 

 

You will notice in both images that the aleutian high is ridging once again though in today's ECM its origins are somewhat further west than in the GFS. However in both cases this seems happens in tandem with a rise of pressure over the north atlantic.

 

Now - I'm not saying that this WILL happen. This is not a forecast. But I did point out that the vortex shifting to the Siberian side might bring about a northerly with an amplified pattern still operating in the pacific and atlantic - and now that ECM looks to be toying with it too it is worth keeping an eye on. Who knows where ECM 268 would go - not obvious to me, and amplification possible especially if the core of the low heights continues to transfer east. That, incidentally, is what the strat signals would suggest even after a slight backtrack today (the vortex is no longer forecast to split quite as fully...)

Edited November 20, 2013 by Catacol_Highlander

[Snowman.]

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=9&mode=0&carte=1

 

The coldest run of the ensembles.

 

For all you to browse.

[phil nw.]

Yes I think its encouraging to see still some energy heading into southern Europe, also the PV reluctant to set up shop in its normal resting place, in that run of hideous mild winters we often saw only one outcome with this type of mid latitude high, an eventual sinking to usher in a spell of mild sw'erlies. I'm not sure how long we can sustain it without some change in the upstream pattern. But as long as the PV doesn't enter into courtship with southern Greenland then we can view this as a holding pattern.

I lost my o.p. trying to correct something but just to add- the GFS mean jet pattern for the next 2 weeks  doesn't scream a quick return to zonality.

http://modeles.meteociel.fr/modeles/gens/run/gensnh-21-3-240.png?12

 

evidence of that split flow with a block somewhere around NW Europe.Something of a holding pattern as we say until we see a more defined trend although earlier anomals hinted at ongoing Atlantic ridging with further upstream buckling.

http://176.31.229.228/modeles/gens/naefs/run/naefsnh-0-0-300.png?12

 

that upstream Alaskan ridge appearing again.Despite the cold core the vortex is still showing some signs of minor disturbances.

Edited November 20, 2013 by phil nw.

[Frosty.]

The Ecm 12z ensemble mean keeps the rather cold and anticyclonic spell intact until T+240 hours, the PFJ is shunted further north compared to the 00z although it looks like changes would be afoot by early next month as the atlantic looks to be cranking up but the next 10 days look chilly with winds falling light, widespread frosts, fog becoming more widespread and reluctant to clear as the pattern becomes stagnant, perhaps turning windier and more unsettled across the far northwest / north of the BI later next week with temps recovering closer to average but temps remaining below average for most of us..it's a relatively wintry outlook minus the snow..for now.

[radiohead]

I'm quite surprised to see the control and several of the ensembles all showing an "interesting" looking T384.

 

 

Operational :

 

 

Control :

 

 

P 10 :

 

 

P 1

 

 

P 9 :

 

 

P 12 :

 

 

P 18 :

 

[Joe Levy]

At least we know where you are now! Not sure what a snow shower in leeds has to do with model accuracy? We may be mixing micro/macro ??

I agree about the micro/macro bit though the radar makes it look like a bit more than a snow shower lol, but I might be misinterpreting it http://www.raintoday.co.uk/

Also look at the dew points for that area, above zero interestingly! http://www.weatheronline.co.uk/weather/maps/current?LANG=en&CONT=euro&LAND=UK&REGION=0003&SORT=2&INT=06&TYP=taupunkt&ART=tabelle&RUBRIK=akt&DATE=--&CEL=C

However the model output was actually pretty accurate, especially on the higher res. models e.g. 

It shows snow over some upland areas tonight, so obviously wintry precipitation is feasible elsewhere given the marginality of it all

Edited November 20, 2013 by Joe Levy

[Frosty.]

Tonight's GEM 12z shows the fine spell breaking down by the end of next week with quite an unsettled atlantic driven outlook thereafter with temps probably fluctuating between mild and rather cold, stronger winds and rain interspersed by sunshine and showers.

[bluearmy]

I agree about the micro/macro bit though the radar makes it look like a bit more than a snow shower lol, but I might be misinterpreting it http://www.raintoday.co.uk/

Also look at the dew points for that area, above zero interestingly! http://www.weatheronline.co.uk/weather/maps/current?LANG=en&CONT=euro&LAND=UK&REGION=0003&SORT=2&INT=06&TYP=taupunkt&ART=tabelle&RUBRIK=akt&DATE=--&CEL=C

However the model output was actually pretty accurate, especially on the higher res. models e.g. 

It shows snow over some upland areas tonight, so obviously wintry precipitation is feasible elsewhere given the marginality of it all

The shower was a ref to the likely sustainability of the snow within the general rainband. we all know how precip is not something you rely on the models for. They're pretty poor at it.

[Timmytour]

I noticed 1962 in the analog years - a lot of similarities to current output - no need to think December will be a duffer.

 

now

 

 

6 days later.

 

I've been intrigued now for a couple of weeks about how similar the modelled output was to how things were in late november early December 1962. As I've mentioned previously, i doubt that anybody back in late November then, even with all of todays technology at their hands, could have forseen what was coming.  Which is not to say it will come this time, but just goes to show all the cards are still on the table.

One thing about what the models are showing us.  Would I be right in considering that, were we still prone to getting smog, the next couple of weeks would be looking dangerous? I think the last proper and dangerous smogs we had were back in that early December of 1962 before the effects of the Clean Air Act took effect. 

[John Cox]

I've been intrigued now for a couple of weeks about how similar the modelled output was to how things were in late november early December 1962. As I've mentioned previously, i doubt that anybody back in late November then, even with all of todays technology at their hands, could have forseen what was coming.  Which is not to say it will come this time, but just goes to show all the cards are still on the table.One thing about what the models are showing us.  Would I be right in considering that, were we still prone to getting smog, the next couple of weeks would be looking dangerous? I think the last proper and dangerous smogs we had were back in that early December of 1962 before the effects of the Clean Air Act took effect. 

I wonder though.  Was the data output as accurate in 1962 the same as it is today in terms of the charts showing? I would love to think so.

Edited November 20, 2013 by John Cox

[Catacol]

I'm quite surprised to see the control and several of the ensembles all showing an "interesting" looking T384.

 

 

Operational :

 

 

Control :

 

 

P 10 :

 

 

P 1

 

 

P 9 :

 

 

P 12 :

 

 

P 18 :

 

 

3 wave pattern with in my opinion the aleutian high driving it. A possible outcome.

[Iceni]

Technically this might be off topic, but as it does appear at the top of the Threads page, perhaps it needs updating now we're just about to officially enter winter.

 

"Where to post in this area? We have 3 main threads running:
To hunt for the next sign of summer or the next hot spell predicted for 14 days' time, please use the Model Output Discussion thread.
For more in depth, objective summaries of the current model output please use the In Depth Model Discussion thread.
And finally, to go mad when a hint of hot weather is suggested and then despair when it fails to arrive, or to moan because it seems so unfair that we are an island surrounded by sea at the end of the Gulf Stream, please use the Model Mayhem, Moan, Ramp, Go Nuts thread."

 

I'm not proposing to 'hunt for the next hot spell' for another 6 months. Quite the opposite.

[Matty M]

The continued progression west of the initial block continues on the 18z.

 

What could have been with a little change!

Although at this rate, parts of Shetlands may get something come the day.

Edited November 20, 2013 by Matty M

[SMU]

Missed the last 24 hours

 

but finally it would seem the GFS has caught up with the initial placement of the tropical storm track-

 

http://modeles.meteociel.fr/modeles/gfs/runs/2013112018/gfsnh-0-72.png?18

 

S

[Cloud 10]

A rather flat looking 8-14 dayer from NOAA this evening and they do mention the "z" word

in their discussions.

 

Climate Prediction Center - 8-14 Day 500mb Outlook

 

 

 

An interesting paragraph included in those discussions about beyond week 2 as well.

 

GUIDANCE FOR THE PERIOD BEYOND WEEK-2 HAS BEEN VERY INCONSISTENT OF LATE, WITHTHE ONLY REASONABLE SIGNAL BEING SOME CONTINUATION OF THE QUASI-BLOCKINGPATTERN OVER THE NORTH PACIFIC. TO BE SURE, THIS PATTERN IS ONE OF THE MOREPERSISTENT PATTERNS OF INTERNAL VARIABILITY IN THE EXTRATROPICS DURING WINTER.THE LARGEST UNANSWERED QUESTION OF PERIOD LEADING UP THE CHRISTMAS SEASON ISWHETHER ANY PERSISTENT HEIGHT RISES WILL OCCUR ACROSS PARTS OF THE NORTHWESTERNATLANTIC AND GREENLAND, SOMETHING THAT HAS NOT HAPPENED THUS FAR THIS COLDSEASON. ADDITIONALLY, THE MJO REMAINS FAIRLY INCOHERENT, AND ANY REORGANIZATIONOF THAT IMPORTANT TROPICAL PHENOMENON WILL LIKELY HAVE RAMIFICATIONS FOR NORTHAMERICAN HYDROCLIMATE LATER IN DECEMBER.

 

 

 

 

[shaky]

The continued progression west of the initial block continues on the 18z.What could have been with a little change!Although at this rate, parts of Shetlands may get something come the day.

you never know matty m we might see a change in the models tomorrow.slowly things are trending west again.

[Matty M]

If we wish hard enough we can turn this very decent looking chart in to a massive model climb down!

 

Not too much would have to change for a significantly colder outlook to pop through!

 

[Joe Levy]

There has been quite a significant westward alteration since the 12z. The sinking section of the polar vortex is further west, and so is the high pressure cell

[shaky]

Missed the last 24 hoursbut finally it would seem the GFS has caught up with the initial placement of the tropical storm track-http://modeles.meteociel.fr/modeles/gfs/runs/2013112018/gfsnh-0-72.png?18S

it seems to be a long time since you were on here steve.one thing ive noticed is the upper cold pool across eastern europe has been modelled to come further west than originally thought.its actually quite close to eastern Britain. Wonder if we can get it even more west?

[Matty M]

That shortwave will still come through towards Iceland, but i wouldn't call this dead in the water just yet.

 

However would have to be some major model change for it to occur.

 

Step one would be the small low to the northeast of the Azores gearing up in future runs!

[radiohead]

The continued progression west of the initial block continues on the 18z.

 

What could have been with a little change!

Although at this rate, parts of Shetlands may get something come the day.

 

Yes, Shetlands have gone from 0 degree uppers to -8 uppers since the 12Z run.

 

And at T102 Lowestoft has gone from +2 to -6 uppers...

Edited November 20, 2013 by radiohead

[Gibby]

About as poor as it can get on the ECM 10 day mean tonight.

 

http://www.wetterzentrale.de/pics/Reem2401.gif