Model Output Discussion 13/11/13 >

[summer blizzard]

Mixed feelings regarding the outputs today in that i can understand why some are not as happy given the increased marginality from the prospective easterly however the important thing is that despite GFS, GEM and ECWMF disagreeing on the setup all three show at least surface cold remaining at day 8 which means any outright breakdown is outside the high resolution timeframe, let alone the reliable timeframe.

 

GFS still good..

 

 

Fair chance of snow north of Birmingham.

 

 

Marginal uppers but probably snow..

 

[forecaster]

Mixed feelings regarding the outputs today in that i can understand why some are not as happy given the increased marginality from the prospective easterly however the important thing is that despite GFS, GEM and ECWMF disagreeing on the setup all three show at least surface cold remaining at day 8 which means any outright breakdown is outside the high resolution timeframe, let alone the reliable timeframe.

 

GFS still good..

 

 

Fair chance of snow north of Birmingham.

 

 

What is that field? 850hPa Theta-e?

[summer blizzard]

What is that field? 850hPa Theta-e?

 

Yeah. I tend to find (especially in winter when high pressure is around) that's it's a better indicator of surface cold (inversions) than regular uppers.

[Frosty.]

There are a large number of GEFS 06z perturbations which are very wintry in and around the T+144 hours timeframe, some with blizzard potential and gale force ENE'ly winds, and others with a lighter NE'ly flow with widespread sharp frosts, the 6z mean supports these type of synoptics, it could be a very wintry spell developing next week. 

[shedhead]

What is that field? 850hPa Theta-e?

Shown as 850 Pot Aquiv temp on wetterzentrale. 

Edited November 15, 2013 by shedhead

[Man With Beard]

Is there an example of an ensemble that shows the output consistantly at -5 for 5 days? Dont think Ive ever seen one.

Sorry of this has already been answered, but Jan 2013 saw the London ensemble mean below -5 for 10 days! However, I can't remember seeing this for an event starting 5 days away, it normally happens when it's cold at T0. Another reminder that the longevity of cold can upgrade significantly once it is in place.

Is there an example of an ensemble that shows the output consistantly at -5 for 5 days? Dont think Ive ever seen one.

[terrier]

Strap yourself in again not long to go till the next ride on the model rollercoaster   

[radiohead]

Potenital snow in northern Scotland is now just 66 hours out. The initial phase of the cold spell is well within the reliable timeframe now.

 

[cooling climate]

Great to see no sign of the zonal wave train in the model

output that some had been calling for the rest of November.

Hopefully it will be a good evening to come model wise and

quite simply the more amplification the stronger and more

prolonged the cold.

[Barry12]

78 hours in and the cold air is in for the whole of the UK

 

 

84 hours in and we have -8 uppers for many parts of Scotland

 

Edited November 15, 2013 by Barry95

[Mucka]

Big difference with how far NE the Azores high ridges in across the SW of the UK compared to yesterday. Fly in the ointment in the short term.

 

Yesterday

 

 

Today

 

Edited November 15, 2013 by Mucka

[terrier]

T84 cold flooding south looking good

[Panayiotis]

GFS 12z a little different to the 06Z at 96hrs, vertical component to the SW of Greenland isnt as steep, resulting in a 'flatter' high..

[radiohead]

Not so good at T90. Less of a push into southern Greenland than the 0Z at this point.

 

[Cecil Hogmanay Melchett]

GFS brings in a hefty North westerly tuesday with heavy snow showers pouring in off the Irish sea!! 

[Mucka]

T84 cold flooding south looking good

 

Looks less cold and amplified to me compared to yesterday but let's see how it turns out overall.

 

[Summer Sun]

12z not looking quite as cold so far compared to the 06z

 

 

06z

 

[Summer Sun]

Colder uppers are in getting in slowly for the north

 

 

Edited November 15, 2013 by Summer Sun

[swfc]

Slighty flatter at 102 hrs and looks like a poorer run already imo!only one run tho and fi will no doubt be biblical

[Barry12]

Colder uppers are in getting in slowly for the north

 

 

 

We have cold uppers at just 78 hours, -8 uppers for many parts of Scotland, so I wouldn't say there getting in slowly.

 

[Summer Sun]

The high out in the Atlantic is causing the problems with the models at the moment where it ends up is going to be crucial

 

[radiohead]

Flatter, further east.

 

[Mucka]

For me this is a disappointing run. It is a continuation of the downgrades we have seen today of the cold and snow prospects with the pattern getting ever flatter and the cold slowly being shunted East but that's just my take.

Edited November 15, 2013 by Mucka

[Cecil Hogmanay Melchett]

GFS is picking up a hell of a lot of instability in the flow so as i have been saying some places up north and west could get pounded next week,and it gives credence to the metoffice update taking of potentially 'significant accumulations' and not exclusively to hig ground. 

[WillinGlossop]

If that wind direction and precip were as per this run the peak district would get a bit of snow from this set up.....