winter model discussion Winter Model Discussion 06Z 17/02/13 onwards.

[rory o gorman]

Almost identical to last year in F.I with strong WAA . I would rather not see this in march

[PB22]

Interesting few days ahead, a lot colder and a lot cloudier with some snow flurries around. East Anglia/Kent have to be at greatest risk of seeing some "proper" snow showers over the weekend, when flurries may extend a little further north and west for a time. Precipitation amounts virtually impossible to call at this stage...I can remember an occasion when promising synoptics delivered nothing even though it looked odds on for a dumping in the southeast, yet other times seemingly mediocre synoptics delivered more. It really will be a case of nowcasting. Longer term, high pressure holding on for several days (take GFS FI with big pinch of salt) with temperatures slowly recovering. A lot of it will come down to sunshine amounts, and I fear these will be limited, especially in the east.

[SomeLikeItHot]

GFS 12Z pushes the higher further north, compared with 6Z, but it never quite makes Iceland. Will it reach Greenland on later runs?

12Z

6Z

Edited February 19, 2013 by SomeLikeItHot

[Frosty.]

I think we may run out of ways to describe high pressure in the next 10-15 days and if the ecm 00z is anything to go by, the next 20+ days, it looks very stagnant, anticyclonic, settled, high pressure dominated and benign for most of the uk apart from the south where it will be breezier, colder, cloudier and with a risk of powdery snow flurries but the calm weather in western, central and northern areas will then also engulf the southeast during next week.

Edited February 19, 2013 by Frosty039

[UV-RAY]

I think we may run out of ways to describe high pressure in the next 10-15 days and if the ecm 00z is anything to go by, the next 20+ days, it looks very stagnant, anticyclonic, settled, high pressure dominated and benign for most of the uk apart from the south where it will be breezier, colder, cloudier and with a risk of powdery snow flurries but the calm weather in western, central and northern areas will then also engulf the southeast during next week.

Faux dry?

[Frosty.]

Faux dry?

Faux cold once the colder uppers are mixed out with cold left at the surface but at least there will be frosts galore and plenty of sun although initially, the sunshine is most likely in extreme western areas and northern half of scotland.

[snowking]

I think longer term people have been a little over optimistic today.

The GFS route of waning the high and removing it to the SE looks to be the favoured solution presently, and it is then that we see the potential for the Atlantic vs Scandi cyclogenesis battle to commence.

The ECMWF is quite plausible in that it sends another shot of WAA up from the azores into the UK high, but if we have a look at the setup thereafter:

With the positive tilt on the Atlantic troughing, the high only really has one way to go.

If we can shift this another 4-500 miles west and get some of that WAA towards the west of Greenland then there may be cause for more optimism, but for now I remain rather low in confidence for the scandinavian trough to pay us a visit - I would rate it around 20% chance at present.

6z GFS Ens Mean proves a pretty good guide to where present ensemble mean guidance points beyind day 10:

You can see the battle of the lows taking place, with the Atlantic energy currently favoured to influence us the most....whether that proves the case remains to be seen

SK

EDIT: On the plus side, in the shorter term, as we come into the range of higher resolution modelling:

http://www.meteocenter.eu/fajli/index.php?domain=euNMM12km&region=EU&forecast=Precip&time=135

Something a little more significant on offer there in comparison to the flurries expected before hand

Edited February 19, 2013 by snowking

[Barry12]

Yet again the models have watered down this Easterly, look's like it will be similiar to the short lived slack Easterly back in December which gave a few cold days and then mild proceeded. Snow will be restricted to the SE and at most I'd say 2-4cm. Hopefully this high pressure will bring some sunny and mild days to start the Spring. If it's not cold enough for snow it might aswell be mild in my opinion

[bluearmy]

I think longer term people have been a little over optimistic today.

The GFS route of waning the high and removing it to the SE looks to be the favoured solution presently, and it is then that we see the potential for the Atlantic vs Scandi cyclogenesis battle to commence.

The ECMWF is quite plausible in that it sends another shot of WAA up from the azores into the UK high, but if we have a look at the setup thereafter:

With the positive tilt on the Atlantic troughing, the high only really has one way to go.

If we can shift this another 4-500 miles west and get some of that WAA towards the west of Greenland then there may be cause for more optimism, but for now I remain rather low in confidence for the scandinavian trough to pay us a visit - I would rate it around 20% chance at present.

6z GFS Ens Mean proves a pretty good guide to where present ensemble mean guidance points beyind day 10:

You can see the battle of the lows taking place, with the Atlantic energy currently favoured to influence us the most....whether that proves the case remains to be seen

SK

EDIT: On the plus side, in the shorter term, as we come into the range of higher resolution modelling:

http://www.meteocent...Precip&time=135

Something a little more significant on offer there in comparison to the flurries expected before hand

The 12z gefs painting some crazy NH profiles re thicknesses and uppers. as you say, we appear to be just too far west but there are some parts of the NH where spring will be much delayed this year.

[AWD]

I really don't see a quick return to temperatures that I would call mild. What seems to be likely is that the upper air cold pool we will receive in the next 36 hours looks like slowly getting mixed out as we go through early next week, but this process not really affecting the surface until later next week. The 192 hour GFS 2m temps are still what i would call cold for much of central England at this time of year;

And after this time, the GFS operational is shown to take one of the mildest routes in its ensemble suite;

with many members showing some rather colder options in FI along with the mean not getting above 0hpa and little support for double figure temperature throughout the run. What does look likely however is a continuation of the dry, settled conditions many of us are currently experiencing with little projected PPN for the foreseeable;

So settled, dry and often on the cold side looks the form horse for the remainder of this week and for the first half of next week at the surface too, despite the modification of upper air temps.

Edited February 19, 2013 by AWD

[Summer Sun]

GFS ensembles have good agreement to February 28th after that there is a lot of scatter

Temperatures should recover to around average for a time next week after a cool weekend

[bluearmy]

Yet again the models have watered down this Easterly, look's like it will be similiar to the short lived slack Easterly back in December

that was a slack lee easterly behind a dropping shortwave which lasted a day or so. i love the 'attitude' from some of the northern contingent over this block. from where i'm sitting the eastern side of n england has as much chance of seeing lying snow as the se. if that happens, i trust those posters who have been imby for the past week will come on and apologise.

[chris55]

p1 is at it again, ...........I'll get my coat........I might need it, lol.

Edited February 19, 2013 by chris55

[Cheshire Freeze]

Following the operationals only, it seems that the pendulum has swung away from a -NAO at day 10. The majority of the ensembles disagree however with the 12z op's prognosis of the further outlook. How useful the ensembles are at the moment though is open to question.

Ensemble mean at day 10...

[chris55]

Following the operationals only, it seems that the pendulum has swung away from a -NAO at day 10. The majority of the ensembles disagree however with the 12z op's prognosis of the further outlook. How useful the ensembles are at the moment though is open to question.

Ensemble mean at day 10...

CC with such wild differences due to the two options available (Snowkings race!) The mean is utterly useless in FI. Although from a glass full to the brim view we do need to watch things closely.

EDIT, although the mean chart you posted shows stalemate at present!! Arctic air held to the north east, Atlantic air held to the south west with the UK in the middle.

Edited February 19, 2013 by chris55

[shaky]

Nothing on the ecmwf lol!!i think everyones tired of this northerly and southerly pushes now!!

[Cloud 10]

p1 is at it again, ...........I'll get my coat........I might need it, lol.

A few more eye catching options for the first week of spring..

http://modeles.meteo...-1-1-300.png?12

http://modeles.meteo...-3-1-300.png?12

http://modeles.meteo...-4-1-312.png?12

http://modeles.meteo...15-1-360.png?12

http://modeles.meteo...19-1-252.png?12

http://modeles.meteo...20-1-336.png?12

[Cheshire Freeze]

Nothing on the ecmwf lol!!i think everyones tired of this northerly and southerly pushes now!!

Well there's definitely a stronger flow at 120 than on the 0z

Still -6 to -8 upper air hanging around

Edited February 19, 2013 by CreweCold

[PB22]

Nothing on the ecmwf lol!!i think everyones tired of this northerly and southerly pushes now!!

Why don't you say what it's showing then?

[shaky]

Well there's definitely a stronger flow at 120 than on the 0z

Still -6 to -8 upper air hanging around

yeh i was going to say it looks very good at 120 hours!!looks like that would bring snow showers across eastern parts of england!!

[SE Blizzards]

Following the operationals only, it seems that the pendulum has swung away from a -NAO at day 10. The majority of the ensembles disagree however with the 12z op's prognosis of the further outlook. How useful the ensembles are at the moment though is open to question.

Ensemble mean at day 10...

BOM looks quite similar too at day 10...

[shaky]

Why don't you say what it's showing then?

Just had a look!!slight northward movement maybe and good 850hpa temps of -6 to -8'!!

[bluearmy]

in anticipation of the T96 FAX later, i note the formation of a tiny circulation on the front over scandi T72. navgem develops that into a discreet shortwave crossing se uk at T96/T120. this disturbance is picked up by many of the ops but is hardly noticeable on most of them unless you see the precip charts which show an uptick as it crosses us. surely navgem wont make the running on this? it overplayed the easterly so it does appear to be taking its position at the bottom of the pile as expected.

[itsnowjoke]

Why don't you say what it's showing then?

yes a shaky post indeed

[Cheshire Freeze]

BOM looks quite similar too at day 10...

I wonder if the ECM will wander off in this direction in its later stages. Soon to find out....