Model Output Discussion

[PB22]

The 12z UKMO is quite encouraging for northerly hunters:

http://www.wzkarten.de/pics/Rukm961.html

http://www.wzkarten.de/pics/Rukm1201.html

http://www.wzkarten.de/pics/Rukm1441.html

[Iceberg]

I'd agree Timmy. The GFS outlook ties in very well with today's Met Office 6 - 15 day outlook. A very good outlook for northern hills in particular in terms of snow potential. Lower down and towards the south, I wouldn't expect much other than cold rain if the 12z run came off.

What north-easterly?!

Well GFS gives heavy snow for the south at T180Z, correctly according to predicted thicknesses and 925 temps. The lower res side of things also has the lower atmosheric conditions the right side of marginal.

The 12z UKMO is quite encouraging for northerly hunters:

http://www.wzkarten.de/pics/Rukm961.html

http://www.wzkarten.de/pics/Rukm1201.html

http://www.wzkarten.de/pics/Rukm1441.html

Yep very GFSesque.

[cooling climate]

Argh I had just written a post then went to see if the UKMO run was out yet and I

somehow managed to delete it.

At t120 plus hours out there is still plenty of time for a pronounced eastward shift

from what the runs are showing to day(have now just seen the UKMO and is very

encouraging). The shortwaves that the GFS run is showing may not even exist

nearer the time and the movement of the split vortices's will not be accurately

modeled this far out. Although the cold spell this week is definitely a lot tamer than

what was being shown five, six days ago, some areas will still see some quite wintry

weather just not as snowy or cold as was being shown last week.

As for next week there is the very real possibilities that it could be one of the coldest

and snowiest weeks of the winter for many locations.

Edited February 9, 2010 by cooling climate

[MKN]

I'd agree Timmy. The GFS outlook ties in very well with today's Met Office 6 - 15 day outlook. A very good outlook for northern hills in particular in terms of snow potential. Lower down and towards the south, I wouldn't expect much other than cold rain if the 12z run came off.

What north-easterly?!

I think you will be way off the mark with that, I think the potential for widespread snowfall next week is looking very promising. Of course things between now and then can change due to it being a week or more away but the models look very good as things stand. Im saying that despite being in one of the worst places usually for snowfall from a northerly. If the low pressure to our north east intensifies just a tad and drags down colder 850s any marginallity will be removed.

[Bobby]

I think you will be way off the mark with that, I think the potential for widespread snowfall next week is looking very promising. Of course things between now and then can change due to it being a week or more away but the models look very good as things stand. Im saying that despite being in one of the worst places usually for snowfall from a northerly. If the low pressure to our north east intensifies just a tad and drags down colder 850s any marginallity will be removed.

I agree, uppers look between -5c to -8c on this GFS which should be good enough. Not a bog standard Northerly either with low pressure very near if not right over us which will throw up big instablity meaning potentially widespread snow. The Jan 6th snow that gave major widespread snow to the south came up from a similar looking setup.

[MKN]

The Met Office update seems to suggest rain next week, with any snow confined to Northern Hills.

Oh right, well itl be rain then obviously. Seriously though, they are clearly going against what the models would suggest at this stage, could well turn out to be correct but there outlooks are generally quite vague so until it comes within 3-4days neither the models or the metoffice can guarentee whether we will see rain or snow falling as a result of this northerly. Im just happy that most of the models look to be in favour of snow right now and hopefully that will be the case.

[Guest FireStorm]

What was the infamous country-wide January thunder-snow set up like a few years back? Wasn't that a Northerly with a low pressure moving South ? Is there any similarities on the models for next week?

[bluearmy]

Just in case anyone didnt notice yet - this evolution is soooooo like december. cast your minds back to the evolution we had then and you get a reasonable idea of what to expect next week. at similar range of a week, uppers looked lower then and corrected less cold as verification approached. i would say looking good for the northern half of the uk with the south rather borderline.

[Frosty.]

I am not so keen on the Met Office update! It seems to go with the ECM & GEM scenario, as they expect rain or sleet with hill snow for next week. Snow at times at low levels only in the north. If the update was supporting the GFS scenario, there would be snow across the UK and not just the high ground!

Karyo

You probably won't like the GFS 12z then karyo as it floods the atlantic with arctic air instead of the uk although it does return to the uk slightly modified. Even though the gfs 12z is more like the ecm and gem 00z it still shows a cold and unsettled week which will at least be more interesting than the fairly chilly but mostly settled spell we have for the rest of this week with it's anticyclonic influence.

[MR EXTREMES]

now for the life of me,

i can understand whats going on tonight on the models.

the gfs looks good for who?

i live on the south coast and this is a regular problem in here with one person saying the whole country will get a snow event,

and then the other will be saying rain sleet mix.

i just cant get my head round all this,

the models have completely flip flop around again in the last couple of days.

it went from easterly to north easterly to northerly which of coarse is not uncommon but please some explain what is going on ? please.

and to be honest i think id rather have high pressure sat over the top of us than cold rain of coarse im being selfish.

Edited February 9, 2010 by grab my graupel
Quoted post already moved

[Jayces]

Argh I had just written a post then went to see if the UKMO run was out yet and I

somehow managed to delete it.

At t120 plus hours out there is still plenty of time for a pronounced eastward shift

from what the runs are showing to day(have now just seen the UKMO and is very

encouraging). The shortwaves that the GFS run is showing may not even exist

nearer the time and the movement of the split vortices's will not be accurately

modeled this far out. Although the cold spell this week is definitely a lot tamer than

what was being shown five, six days ago, some areas will still see some quite wintry

weather just not as snowy or cold as was being shown last week.

As for next week there is the very real possibilities that it could be one of the coldest

and snowiest weeks of the winter for many locations.

I think this is one of the big issues with the modern age of technology that we have at our disposable.

These models are great but it seems beyond 24 / 48 hours they still have the potential to change in such a big way that they can leave those hoping for something a week away very dissapointed.

It was only the weekend where we were talking about significant snow for the SE which also started a lot of bickering and anti SE comments and now it's looking like that is not going to be anywhere near as much as forecast if any.

It would be nice to have one more lot of snow during half term but beggars can't be choosers ;-)

[MKN]

I think this is one of the big issues with the modern age of technology that we have at our disposable.

These models are great but it seems beyond 24 / 48 hours they still have the potential to change in such a big way that they can leave those hoping for something a week away very dissapointed.

It was only the weekend where we were talking about significant snow for the SE which also started a lot of bickering and anti SE comments and now it's looking like that is not going to be anywhere near as much as forecast if any.

It would be nice to have one more lot of snow during half term but beggars can't be choosers ;-)

youve obviously not seen the nae model predictions for the south east. 10-15cms of snow somewhere in kent and sussex would not suprise me in the slightest. possibly even more by friday. its close to call though because if the high pressure is closer to us than forecast that precip will be pushed out over the sea. The north east tonight could see some decent showers aswell.

[MR EXTREMES]

just gone though the gfs it looks dam good for the whole country i cant see a problem with all this.

cant see where the rain sleet event for the south comes into question it looks awsome to me.

ukmo looks a little more watered down to me not as good but not terrible something is certainly afoot me think i can see this turning into a great event next week.

block looks good on both ukmo and gfs am i right?

[full_frontal_occlusion]

GFS 12z 150+ has a very flattened Jet over North Africa / Southern Europe, pressure rises over Greenland and Siberian Block holding but gradually drifting east.

The options for snow in the medium term depend on the positioning and depth of any developing low in the GIN/Arctic region whose track will be defined by the Siberian block to the east and the latency between cyclogenesis events off the US eastern Seaboard.

Lack of any real dynamic features (at least large enough for the models to get a grip) is producing this rather benign North Atlantic picture.

As GP suggests AAM is off the scale, the 12z looks like its a good facsimile.

A waiting game springs to mind.

ffO.

[Tim Bland]

In the Meto long range forecast they state cold and unsetled with rain/sleet snow. This is what the models show as well. The only areas that are not currently pogged to have snow next week are coastal areas in the south and the extreme south and south west.

Back to the models and the Ensembles are particularly exciting with uppers in London not forecast to get above -5c until 20th at the earliest. Operational was also on the warm side of the ensembles Many charts coming out this afternoon have shown widespread snow events next week.

My No 1 chart of the day - http://www.wzkarten3.de/pics/Rtavn1681.png

http://expert.weatheronline.co.uk/daten/proficharts/en/2010/02/09/basis12/ukuk/rart/10021612_2_0912.gif

http://www.wetterzentrale.de/pics/Rtavn1744.png

http://www.wetterzentrale.de/pics/Rtavn17417.png

http://www.wetterzentrale.de/pics/Rtavn2162.png

http://www.wetterzentrale.de/pics/Rtavn2164.png

Edited February 9, 2010 by grab my graupel

[The Weather Dragon]

I like the look of GFS for Sun/Mon & Tuesday. If the pattern shown can evolve slightly further East then we are in for some decent snowfall. It wouldn't take much of a shift. JE

[Buzzit]

youve obviously not seen the nae model predictions for the south east. 10-15cms of snow somewhere in kent and sussex would not suprise me in the slightest. possibly even more by friday. its close to call though because if the high pressure is closer to us than forecast that precip will be pushed out over the sea. The north east tonight could see some decent showers aswell.

I repeat as previously that the NAE and NMM have been out of sorts this week.

Often they have been wide of the mark by the +12 timeframe

and with the current model headaches and chop / changes I dont expect that to change

By all means get start to get excited if its within +6 but double check the radar first

Edited February 9, 2010 by Buzzit

[MR EXTREMES]

gfs is only one run plenty of time for change and plenty of good stuff in that gfs.

and the ukmo following gfs or perhapes gfs progressive and ukmo more realistic.

gfs ukmo

nearly identical

Edited February 9, 2010 by grab my graupel

[Harsh Climate]

I like the look of GFS for Sun/Mon & Tuesday. If the pattern shown can evolve slightly further East then we are in for some decent snowfall. It wouldn't take much of a shift. JE

http://www.wetterzentrale.de/pics/Rtavn1681.png

We need the greenland high about 500 miles south east, if were to be guaranteed blizzards. that aint guna happen...

http://www.wetterzen...s/Rtavn1681.png

We need the greenland high about 500 miles south east, if were to be guaranteed blizzards. that aint guna happen...

Jed Bickerdike, on 07 February 2010 - 15:10 , said:I think as things currently stand, snowfall amounts mon-fri next week will be pretty trivial... maybe with the exception of the north york moors.

http://www.wetterzen...cs/Rtavn421.png

http://www.wetterzen...s/Rtavn1261.png

These flows really are quite dry/drizzly flows and with the air being cold rather than being on the right side of very cold, I would except temporary accumulations to thaw inbetween showers. Obviously these charts arent going to be spot on at this stage, so there is a lot of potential down the line

We need a flow where where at the focal point of the squeeze of NE/ Easterly winds, something like this: http://www.wetterzen...00120090202.gif

This would allow for showers to 1.develope in the north sea widely, 2.spread right inland 3.not being under any part of high pressure allowing full convective cababilities...

As things stand at the moment heavy snow mon-fri will be confined to Kent, il try n do a map later

This post I made a few days ago explains why, just before I get lynched...

Edited February 9, 2010 by Jed Bickerdike

[cooling climate]

just gone though the gfs it looks dam good for the whole country i cant see a problem with all this.

cant see where the rain sleet event for the south comes into question it looks awsome to me.

ukmo looks a little more watered down to me not as good but not terrible something is certainly afoot me think i can see this turning into a great event next week.

block looks good on both ukmo and gfs am i right?

The UKMO is a good run and the t144 chart is excellent, a very cold and wintry outlook from

there I would think.

[TEITS]

12Z GEM has the LP much further E compared to the 0Z if you click on the links below and compare.

http://91.121.94.83/modeles/gem/run/gem-0-144.png

http://91.121.94.83/modeles/gem/run/gem-0-156.png

Edited February 9, 2010 by THE EYE IN THE SKY

[Cumulonimbus Tower]

12Z GEM has the LP much further E compared to the 0Z if you click on the links below and compare.

http://91.121.94.83/modeles/gem/run/gem-0-144.png

http://91.121.94.83/modeles/gem/run/gem-0-156.png

so does the ECM

In fact the ECM looks kind of believable atm....

Edited February 9, 2010 by ned

[Iceberg]

As expected ECM concurs with GFS and METO at 144Z shifting the LP 500 miles eastwards, more snow and cold for us !

[MR EXTREMES]

12Z GEM has the LP much further E compared to the 0Z if you click on the links below and compare.

http://91.121.94.83/...n/gem-0-144.png

http://91.121.94.83/...n/gem-0-156.png

so the gem t144 would that be a better chart than the t156?

the ecm looks good aswell t144

t168 oh my

Edited February 9, 2010 by badboy657

[bluearmy]

so does the ECM

In fact the ECM looks kind of believable atm....

Indeed, it seems our own teleconnection experts and strat observers are one step ahead of the models at the moment. stick with the ens although thats not easy as we dont get to see the ecm mean sypnotics.