Model Output Discussion

[kpm62]

That is interesting,looks like that could dump a fair load of snow,if that cold air is with us by then.

[Lewis]

Some fantastic model output this morning. I have to admit over recent days I haven't been happy with the trend of the ECM for the +96/+144 period but thankfully this morning that downward trend has been replaced with a run that has far more potential. The UKMO is disappointing but looking at all the models I would say the ECM at +96 is a fair reflection of what many are suggesting.

http://www.wetterzentrale.de/pics/Recm961.gif

So based on this my summary remains similiar to last night. From midweek snow showers moving into E areas these becoming more widespread and frequent as the week progresses. The only difference I will say this morning compared to last night is during Fri/Sat the snow could move well inland to affect many regions and the showers might be replaced with more prolonged spells of snow.

Moving into Sunday and into the following week and the ECM is even more progressive than the 12Z!

http://www.wetterzentrale.de/pics/Recm1681.gif

Excellent consistency from the models of a Greenland HP. Obviously detail isn't worth discussing but the risk of snowfall looks like continuing into the following week.

I forgot to add that during tonight/tomorrow a risk of light snow in E areas as we pull in the colder E,ly.

http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/02/07/basis00/ukuk/prty/10020818_0700.gif

Morning mate,

Good post. To add to that, looking at the latest 06z rolling out, it looks as if there is some snow potential for eastern areas tonight and during the early hours especially for eastern areas the dew point drops to 0c or below for me also, so i could wake up to a covering tomorrow fingers crossed

Certainly lovely models for viewing this morning, let's hope this continues.

[chionomaniac]

I missed this from the METO, hopefully the 06Z NAE will shed a bit more light.

A developing feature tomorrow, tomorrow night onthe UKMET GM across the south and central regions, intensifying as it reaches the south coast.

Interesting.....Sorry with attachements this time.

And latest GFS agrees

[Lewis]

06z a spoiler with the Easterly mid week onwards, all the cold air much further South into the near continent, due to the HP much further South on this run.

Edited February 7, 2010 by Storm Force Lewis

[Cecil Hogmanay Melchett]

06z a spoiler with the Easterly mid week onwards, all the cold air much further South into the near continent, due to the HP much further South on this run.

yep 6z has the low further south which i didnt want to see but its one operational lets see how the rest pans out.

ps hull played very well/

[Lewis]

yep 6z has the low further south which i didnt want to see but its one operational lets see how the rest pans out.

ps hull played very well/

Cheers mate which hull team though? Because hull city won against man city, then my rugby team Hull F.C hammered Saint Helens in the superleague last night too The man city game cost me my front tooth, celebrating the second goal and smashing it on my table

Regarding the 06z, i think it could be an outlier, or it's just handled the shortwave wrong.

Who knows we'll see how it pans out.

Lewis

[nick sussex]

Looks like the GFS is moving towards the ECM here, as I said last night it was very unlikely both the ECM and UKMO would be totally wrong, the middle ground solution between the GFS and UKMO leaves the ECM looking like the way to go. I'd be very surprised now if theres another shift back towards the previous GFS solutions.

[TEITS]

NAE suggesting some heavier precip moving into the E Anglia during Monday and turning to snow inland.

http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/02/07/basis06/ukuk/prty/10020812_0706.gif

As for the 06Z so far the HP is slightly further S. However we have a SW tracking S during Thursday.

[Suffolk Weather]

I've just looked at the air pressure ensembles for the GFS 00z for Suffolk:

http://cirrus.netweather.tv/ensimages/ens.20100207/00/prmslSuffolk.png

High, Medium or Low. Take your pick.

To my eyes, this could still go very much either way. And that is why we need to be cautious, the extreme cold pool may just stay out in the North Sea.

Edited February 7, 2010 by Suffolk Weather

[Rollo]

My advice is not to hang onto slight changes like that beyond T72, I think the situation is not as fragile as it might appear.

[Tristrame]

NAE suggesting some heavier precip moving into the E Anglia during Monday and turning to snow inland.

http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/02/07/basis06/ukuk/prty/10020812_0706.gif

As for the 06Z so far the HP is slightly further S. However we have a SW tracking S during Thursday.

News 24 have mentioned that.

They're down playing the snow risk in it.

Their words were rain but cold enough for a few flakes of snow mixed in.

I'd translate that as snow in favoured spots inland but not widespread and on high ground eg chilterns.

That ties in with the nae you posted which shows mostly rain.

[Lewis]

On the 06z easterly hits us on friday.

I agree with Nick regarding the ECM and UKMO, i think we are going to get a mixed balance. Correct me if i'm wrong but the ECM has been showing later on in its runs huge potential, although mainly dry with snow showers in the East.

I think the easterly thats brewing on the 06z now for Friday is very good.

[Iceberg]

A cracking 06Z from GFS, oodoodles of precip potential in England from that. upto 168.

News 24 have mentioned that.

They're down playing the snow risk in it.

Their words were rain but cold enough for a few flakes of snow mixed in.

I'd translate that as snow in favoured spots inland but not widespread and on high ground eg chilterns.

That ties in with the nae you posted which shows mostly rain.

With 1000-850 thicknesses of sub 129, 950's of -1 to -2. I would readily expect that to turn to snow as daylight finishes and temps drop a touch, NAE is forecasting temps of 2 or 3C Monday afternoon, but dropping to 1C come the evening.

[Lewis]

A cracking 06Z from GFS, oodoodles of precip potential in England from that. upto 168.

Agree with the precipitation potential, as always more precipitation comes hand in hand with marginal situations, it's all about getting the balance.

Lewis

With 1000-850 thicknesses of sub 129, 950's of -1 to -2. I would readily expect that to turn to snow as daylight finishes and temps drop a touch, NAE is forecasting temps of 2 or 3C Monday afternoon, but dropping to 1C come the evening.

I'll do a post after the 12z and 18z with regards snow risk for the early hours of tomorrow and during the day into Tuesday.

[TEITS]

A cracking 06Z from GFS, oodoodles of precip potential in England from that. upto 168.

With 1000-850 thicknesses of sub 129, 950's of -1 to -2. I would readily expect that to turn to snow as daylight finishes and temps drop a touch, NAE is forecasting temps of 2 or 3C Monday afternoon, but dropping to 1C come the evening.

Interesting that the NAE sugggests the area of rain turning to snow is whilst under the heavier area of precip. This is often the case in marginal situations. So with this in mind it will be difficult to tell how much of it will turn to snow until we actually see how heavy the precip is on the radar.

[chionomaniac]

To my mind a small wedge of higher pressure squeezed between lower pressure around Svalbard would be very consistent with the positioning of the negative mean zonal wind anomalies between 50-60ºN. This would leave an easterly flow the further south you are. There are indications after this that pressures will rise further north with troughing into Scandinavia.

[nick sussex]

On the 06z easterly hits us on friday.

I agree with Nick regarding the ECM and UKMO, i think we are going to get a mixed balance. Correct me if i'm wrong but the ECM has been showing later on in its runs huge potential, although mainly dry with snow showers in the East.

I think the easterly thats brewing on the 06z now for Friday is very good.

Morning SFL

Yes this often happens in these situations, the GFS on one side the UKMO on the other and the ECM was consistently bringing the easterly in later. The GFS 06hrs run is still very nice and overall I'm quite happy with the model output.

http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

If you look at the mean height comparisons for the 00hrs ECM and GFS are in good agreement with that long wave trough stretching all the way from the USA to Europe, the ECM does however have a better looking Omega block. That type of pattern is quite stable and could last a while. The key though is that the positive anomalies don't back too far west.

[Iceberg]

A very similar 06Z to the ECM including the stationary cold pool across the south 168-200. It then continues to follow the ECM and we get a look at what precip the ECM might offer and boy it comes in wheelbarrow loads.

Still it's all FI and subject to change, but as good as you could hope atm.

[TEITS]

It then continues to follow the ECM and we get a look at what precip the ECM might offer and boy it comes in wheelbarrow loads.

Yep we could see some stunning ECM runs over the next few days.

Personally im just hoping the 12Z ECM continues with the same trend as the 0Z and the UKMO jumps on board.

Im going to have a little ramp and say that the potential continues this morning that we could be looking at the best cold spell so far this winter. At the moment it isn't unrealistic that by the end of the week whilst we're enjoying the snowfalls, the model output within the reliable timeframe will be even better!

Obviously there will be uncertainity with regards to the retrogressing HP. Much depends on the exact positioning of the HP and how far S the Scandi trough is and also the exact location. What we don't want is the pattern to be too far W and this leaves vunerable to attack from the SW. However at the moment the trend is excellent from the models beyond +168.

[Snowyowl9]

Interesting that the NAE sugggests the area of rain turning to snow is whilst under the heavier area of precip. This is often the case in marginal situations. So with this in mind it will be difficult to tell how much of it will turn to snow until we actually see how heavy the precip is on the radar.

Upper air isn`t marginal especially for an E-ly not going by GFS and GFS is better in these upper air at close range.

http://www.wzkarten.de/wz/pics/Rmgfs242.gif

http://www2.wetter3.de/Animation_06_UTC/24_30.gif

http://www2.wetter3.de/Animation_06_UTC/30_30.gif

[TEITS]

Upper air isn`t marginal especially for an E-ly not going by GFS and GFS is better in these upper air at close range.

http://www.wzkarten.de/wz/pics/Rmgfs242.gif

http://www2.wetter3.de/Animation_06_UTC/24_30.gif

http://www2.wetter3.de/Animation_06_UTC/30_30.gif

I must admit I am somewhat surprised the NAE is suggesting rain, sleet. However in saying this sometimes the frames on the NAE will change from rain, snow, rain despite conditions remaining the same. I noticed this during the last cold spell.

My personal preference is the NMM but I need to renew my subscription. Currently waiting because I don't want to put a jinx on the cold spell.

[Cecil Hogmanay Melchett]

Upper air isn`t marginal especially for an E-ly not going by GFS and GFS is better in these upper air at close range.

http://www.wzkarten.de/wz/pics/Rmgfs242.gif

http://www2.wetter3.de/Animation_06_UTC/24_30.gif

http://www2.wetter3.de/Animation_06_UTC/30_30.gif

wow look at the rain into southern greenland.

i wonder if its a coincidence that its been a mild winter up there while its been well below average here.

[Frosty.]

A good 6z for cold fans, snow for everyone at some point during the run with the week ahead splitting the uk in two with most of western britain being mainly dry with sunny spells and overnight frost and fog, still the risk of a rogue wintry shower as well. Eastern britain becoming colder through the week with an increasing risk of snow showers in eastern counties of both england and scotland. FI looks very wintry on most of the output today with the main snow threat probably transferring to northern britain later.

[evansc5487]

Hi guys, I don't really ever post much in this thread, just watch and read normally but am a big fan of the cold snowy weather and read with interest what the models may bring next.

I don't really understand it all that well but find it very interesting. Anyway it seems for the past 3 weeks or so that very cold air has just been sitting to the east of us without make that much of an inroad.

This is very frustrating for fans of the cold weather. It seems to me that this cold pool of air is just not going to make it right accross the Uk to full effect so to speak. Can someone explain why it is so rare for really cold air to make it all the way accross the uk from the east and why so many times it just sits just to the east of us and does not make it much further.

What is stoppping this cold air making it all the way here with a very potent spell of cold weather. Is it the atlantic low pressure systems that are blocking it or is it the jet stream position. What setup do we need for this very cold air to make it all the way accross the UK?

Sorry for rambling on.

[cooling climate]

Looks like the GFS is moving towards the ECM here, as I said last night it was very unlikely both the ECM and UKMO would be totally wrong, the middle ground solution between the GFS and UKMO leaves the ECM looking like the way to go. I'd be very surprised now if theres another shift back towards the previous GFS solutions.

To me Nick it looks as though the 06z GFS run out to t144 has moved towards the

UKMO rather than the ECM, with the UKMO as the middle ground.

Having said this because the rest of the run is so different to the 0z run I do not know

if it can be trusted or not. Best to see where it lies in the ensembles I think.