Model Output Discussion - 23rd Jan - 12z onwards

[Ice Day]

GFS 18z Mean @ 114

 

http://modeles.meteociel.fr/modeles/gens/runs/2015012918/gensnh-21-1-114.png

 

More blocking over Iceland with 'green' heights there now- the 12z mean has the jet south already of this location.

 

Also the low in Europe dropping further south- pushing everything west.

 

4 consecutive upgrades from the GFS ...... ( in terms of longevity of cold- If we carry on like this with the energy going in the right places the -10c line will move back into EA at 144 on the overnights....

 

S

PS look for the mean to reach -8 @ day 6 for the 18z.

 

I must admit that I now view the GFS differently since the upgrade (and I'm not saying this because it's churning out nice runs!).  It seems to be a far more solid model, amply demonstrated by it's 'win' over the ECM on Wednesday during the USA's 'Nor'easter'.  No science behind this, just evidence of my eyes!

[Cheshire Freeze]

The control is fairly epic at 156 hours and the mean looks better too. Must be some very good perts in those ensembles.

[Jason M]

The difference between the 192 18z mean and the 12Z mean is jaw dropping! We replace a mean westerly with a mean easterly!!!!

[Mucka]

GFS 18z ensembles have flipped to an easterly end of high res. Will this be a one hit wonder or is this just more of the progression we have seen through the day?

The Op is one of the most progressive runs in the whole set!

What breakdown?

 

Edited January 29, 2015 by Mucka

[Just Below Zero]

The control is fairly epic at 156 hours and the mean looks better too. Must be some very good perts in those ensembles.

 

Just picked out P 19 at total random at 192 that will do nicely

 

http://modeles.meteociel.fr/modeles/gens/runs/2015012918/gens-19-1-192.png

[Jason M]

Just picked out P 19 at total random at 192 that will do nicely

 

http://modeles.meteociel.fr/modeles/gens/runs/2015012918/gens-19-1-192.png

This one is much more fun!!

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=2&mode=0&carte=0

Great stuff tonight, but what the 18Z giveth, the 00Z taketh away ;-)

Hopefully not this time!

Edited January 29, 2015 by Jason M

[weather eater]

Usually what happens is an easterly appears on the models and slowly but surely we inch away from it. However this time it may be that we are inching towards one.

[Cheshire Freeze]

This one is much more fun!!http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=2&mode=0&carte=0Great stuff tonight, but what the 18Z giveth, the 00Z taketh away ;-)Hopefully not this time!

-12 uppers into the east at 216 hours.

[Nick F]

ECM 12Z ENS for London.

 

 

One or two people were saying this could be a 2 or 3 Day toppler. Well, going by those ENS this cold spell seems to be locked in for at least another 10 Days, or possibly longer.

 

 

Interesting that for London and the SE at least, the coldest period looks to start from Monday, with day maxima and night minima lower than before early next week. This reflects the sustained northerly flow veering northeasterly toward mid-week. Average along with EC and GFS ops show slight rise in temps next weekend - though big scatter by then. Certainly don't buy the 18z progressive return to more mobile Atlantic regime by then.

Edited January 29, 2015 by Nick F

[Cheshire Freeze]

Usually what happens is an easterly appears on the models and slowly but surely we inch away from it. However this time it may be that we are inching towards one.

There's usually a tipping point in terms of amplification or energy distribution in the N Atlantic sector and the 18z (and ensembles) have struck that tipping point. However it can always tip back the other way in this situation...as we've seen so many times before.

[Weathizard]

This one is much more fun!!

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=192&code=2&mode=0&carte=0

Great stuff tonight, but what the 18Z giveth, the 00Z taketh away ;-)

Hopefully not this time!

Indeed. The amount of times I've gone to bed positive about the 18's and woke up to a downgrade from the 0z, summer and winter, must be in the hundreds of times. 'Went to bed with a ten, woke up with a six'

[SMU]

Synoptically on of the best charts you can get

 

http://modeles.meteociel.fr/modeles/gens/runs/2015012918/gensnh-19-1-228.png

 

All models have actually trended to the 00z GEM today !!!!!
S
 

[SE Blizzards]

Interesting that for London and the SE at least, the coldest period looks to start from Monday, with day maxima and night minima lower than before early next week. This reflects the sustained northerly flow veering northeasterly toward mid-week. Average along with EC and GFS ops show slight rise in temps next weekend - though big scatter by then. Certainly don't buy the 18z progressive return to more mobile Atlantic regime by then.

 

Couldn't agree more Nick. GFS 18Z op seems to be way too progressive.

 

Can't quite believe how good the 18Z Ens are. Some staggering members amongst them.

[weather eater]

Yes let's not forget that last nights 18z was an absolute disaster of a run, operationals and ensembles swing like a key swapping party.

Edited January 29, 2015 by weather eater

[Allseasons-Si]

Evening all

 

i don't post much on here but i have to say that the gefs 18z ens are quiet astonishing @ just 144 hrs

 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=144

 

168 hrs,i know i am pushing it

 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=168

 

even out to 192 hrs,i am drooling like my Alaskan malamute lol

 

had three snow events here this winter,i Do hope others get what they deserve in the next couple of weeks+,best of look guys

Edited January 29, 2015 by Allseasons-si

[Bartlett High]

I always thought that an easterly ,although cold,was always a dry direction precip. wise.

[Neilsouth]

I always thought that an easterly ,although cold,was always a dry direction precip. wise.

 

Depends on a number of factors, one of them being -10 850's would be good, can cause some great convection over warmer seas!  As has happened many times in the past 

[Daniel*]

Usually the most significant cold spells - occur by a flick of the switch so to speak. Models really are gathering pace for a much colder February, cold is being extended and extended over the past few days; with increasing support for E'ly solutions. Can't help but think we're on the cusp of something special.

[ITSY]

 

...Almost feeling like an Ian Brown WTF moment. Those are SOME ensembles. A hell of a way to go before either uniformity or agreement, but some serious eye candy floating about. SM may have had a stroke of foresight when commenting on the JMA earlier...

[Nick F]

I always thought that an easterly ,although cold,was always a dry direction precip. wise.

Dry, until it crosses the North Sea and picks up moisture in the lower layers, in winter ... if there is steep lapse rates (cold pool aloft) - this moisture can lift into cumulonimbus clouds bringing snow showers to eastern UK in the coldest easterly flows, if lapse rates are weak then you get low stratus and drizzle or snow flurries. I suspect the latter if winds turn easterly later next week, unless we can get deep enough cold air out from the east.

Edited January 30, 2015 by Nick F

[Duane S.]

I can see it has already, quite rightly, been well covered in the last hour or so but this is the best set of GEFS ensembles I have seen in a long long time...

 

Welcome to February folks!!

[Geordiesnow]

Dry, until it crosses the North Sea and picks up moisture in the lower layers, in winter ... if there is steep lapse rates (cold pool aloft) - this moisture can lift into cumulonimbus clouds bringing snow showers to eastern UK in the coldest easterly flows, if lapse rates are weak then you get low stratus and drizzle or snow flurries. I suspect the latter if winds turn easterly later next week, unless we can get deep enough cold air out from the east.

 

Thats the problem with easterlies and the one next week could end up like that if high pressure is too close anyways. We certainly not going too see the such low thicknesses as we have now so we just got to hope there is enough instability to produce the sunshine and shower set up. You need more than just cold hpa temps to produce the goods, especially for an easterly. 

 

That said, some promising trends that the cold may prolong but there will no doubt be further changes within the coming days. 

[Midlands Ice Age]

With this cold spell now upon us and the potential breakdown veering all over the place in FI, we are not into Feb yet! Could it be that the OPI is about to prove itself as a reliable tool after most of us thought it was bust.....

 

Looks to me as if the OPI could have got it spot on! 

 

MIA

[John Cox]

GEFS out to 120 and I'm liking them a lot!!!! Much better heights to our northwest.

Control here

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=120&mode=0&carte=0

This isn't the best of them either!!!

Hi,

 

This may have been asked before but I cannot find the answer on the learning part of the forum:

 

What is the difference between the control run and the operational run and which is the most accurate , if either may be the case?

 

I do understand the concept of the ensembels and the different perturbations etc.

[Midlands Ice Age]

I think no, The OPI should have produced at lot earlier if it is to be believed a useful tool

 

Disagree Biggin,

 

It forecast a stormy mild Dec,, a cooling Jan (about average temps) with the jet steadily moving north of west, and a very cold end (Feb - Mar) with a scandy. high.

I think it was others who posted who built it up to a 3 month solid freeze.

 

It has not been proved or disproved yet in my opinion.

MIA