Winter Model Discussion 18Z 12/2/13 onwards.

[SMU]

Well ive juist scanned the T2m ECM ensembles, the 500 MB mean - & some other variables in the suite & the operational looks a tad subdued & out of kilter-

So rather than discount it I will file it in the - probably needs a 12z rerun today. - it does have occasional mistep.

Ironically the GFS is model of choice today, however without all the Euros on board its unclear.

Anyway GFS 06z, the worst run of the day shaping up to be stella going by the T90 chart...

http://modeles.meteociel.fr/modeles/gfs/runs/2013021506/gfsnh-0-90.png?6

Remember my favoured track is Norway, Finland, Germany , Paris.

S

[TEITS]

This is shaping up very nicely.

Always rated the GFS as the best model.

[BLAST FROM THE PAST]

Should be a seperate thread for upto T+144 and any post for after that removed

No because models go beyond that and it is the Model Thread

BFTP

[offerman]

Totally agree with you bud on your comment below.

snowblizzard

• 
  

Posted 15 minutes ago

weather eater, on 15 February 2013 - 09:19 , said:

Yes cool by day, cold at night is how I would read it, my comments on cold air masses were more about how the ECM evolution has changed and were not suggesting that it will be mild, much will depend on cloud cover, one of the features this winter has been that other than for a brief period we have not seen really cold night time minima’s, certainly in my neck of the woods clear nights and sunshine have been rare, even for this part of the country (I miss East Anglia).

[phil nw.]

Yes i have been concerned about the high being too close to the UK for a decent long fetch easterly with convective possibilities reduced, and the mean outputs over the last few runs have generally showed this.

No denying it`s a colder outlook as we go into next week but the pattern at the moment tends to favour a drier continental flow.

However those heights anomaly forecasts are showing something that more snowy could be in the further outlook

Retrogressing heights across the north and undercutting low pressure-channel low?

This evolution would back the flow from a dry south of east-next week-to eventually north of east and with more instability.

If we get the cold here first then things could develop nicely from there as frontal systems attack from the south/south west.

[No Balls Like Snow Balls]

The worlds leading weather model has the cold air incoming fast Tuesday evening with some light wintry/snow showers on the East coast.

[No Balls Like Snow Balls]

It's an upgrade over the 00z in the mid term with the cold air making it over the UK quicker

Edited February 15, 2013 by No balls like Snow Balls

[shaky]

It's an upgrade over the 00z with the cold air making it over the UK quicker

Considering that the 06z has a tendency to push things east this surely must be a good sign for the 12zs!!

[mountain shadow]

A SE,ly flow will generally bring shower activity to Scotland and NE England but rarely for E Anglia/SE. However the long fetch across the N Sea could potentially make it marginal. Ideally we want a ENE,ly that will suit nearly everyone.

A SE flow also delivers for eastern NI. Received well over a foot last month from the similar scenario. The cold uppers over the even warmer Irish Sea can deliver.

The ECM has been very consistent with this.

[chris55]

06z looking nice, block well oriented and further north than the 00z

Edited February 15, 2013 by chris55

[phil nw.]

Again decent cold coming west next week.A area of snow moving south from Norway trough Denmark and Germany quite early on but that disturbance staying east of the UK.

Looks like some flurries for the east from mid-week but perhaps the main interest will be later from the south west.

[No Balls Like Snow Balls]

It's a really good run from the GFS upto T144. Shame it is a load of old rubbish though with the credibility of a Findus lasagne (sorry Findus thats a bit harsh to compare you with the GFS)

[snowblizzard]

During 1987 we actually had uppers of around -18C.

I never look for a repeat of Jan 87 anymore because it really was a unique event. Very rare to have an incredibly cold airmass that bitter to advect SW and then have the perfect synoptics to bring this to the UK.

This is why at this stage im not that concerned with the UKMO/ECM. For the UK it really is a fine margin if we can get the perfect placement and orientation to advect the cold pool perfectly for the UK. I expect changes with regards to convective potential on every single model run over the next few days.

Better 06Z with the SW further W.

http://www.wetterzen...cs/Rtavn781.png

Yes, a very rare event, we can but wish though!

[fergieweather]

Looks like some flurries for the east from mid-week but perhaps the main interest will be later from the south west.

Precisely Exeter's view and including the latter.

[johnholmes]

Yes i have been concerned about the high being too close to the UK for a decent long fetch easterly with convective possibilities reduced, and the mean outputs over the last few runs have generally showed this.

No denying it`s a colder outlook as we go into next week but the pattern at the moment tends to favour a drier continental flow.

However those heights anomaly forecasts are showing something that more snowy could be in the further outlook

Retrogressing heights across the north and undercutting low pressure-channel low?

This evolution would back the flow from a dry south of east-next week-to eventually north of east and with more instability.

If we get the cold here first then things could develop nicely from there as frontal systems attack from the south/south west.

yes they show a very similar pattern to that shown on the anomaly charts I posted so good agreement.

The difficulty will continue in just what the surface shows and also the 850mb values. I'll have a look at the NAEFS outputs.

They show, for the same time as the link above, below zero C but they had got an area of -4C over parts of the UK and continent before then. Marginal based on this data but its a long way off so do not expect those 850mb temperatures to be accurate, simply a guide to how the values may evolve.

Looking beyond 2-3 days for ideas on what falls from the skies is a mugs game in my opinion but fun for those seeking a white landscape I suppose?

Edited February 15, 2013 by johnholmes

[Frosty.]

It's a really good run from the GFS upto T144. Shame it is a load of old rubbish though with the credibility of a Findus lasagne (sorry Findus thats a bit harsh to compare you with the GFS)

Yes the gfs is now the form horse, it was lagging behind but it's a sheepskin nose-band ahead of the others, the easterly is nailed, the devil will be in the detail but that's not going to be known for a few more days.

[MR EXTREMES]

During 1987 we actually had uppers of around -18C.

I never look for a repeat of Jan 87 anymore because it really was a unique event. Very rare to have an incredibly cold airmass that bitter to advect SW and then have the perfect synoptics to bring this to the UK.

This is why at this stage im not that concerned with the UKMO/ECM. For the UK it really is a fine margin if we can get the perfect placement and orientation to advect the cold pool perfectly for the UK. I expect changes with regards to convective potential on every single model run over the next few days.

Better 06Z with the SW further W.

http://www.wetterzen...cs/Rtavn781.png

infact its the best gfs run of the winter incredible im loving this right now fingers crossed feb goes out with a bang.

[Thundery wintry showers]

I agree that an ENE'ly would bring greater convective possibilities for eastern areas, as it would most likely draw in colder air (less modification from the SE) and also a longer track over the North Sea. While you don't need something of the intensity of 11th-14th January 1987 to bring widespread convection for central and eastern Britain, there does come a point beyond which we just get stratocumulus stuck under an inversion or dry stable layer.

The ESE'ly showing on the ECMWF this morning would probably be comparably cold in the southern half of the country (less cold airmasses, but shorter sea track)

The GFS's forecast Skew-T graphs only go out to T+84 which isn't far enough out to gauge likely conditions during the easterly, but I have a feeling that we may well end up with stratocumulus trapped underneath a layer of dry stable air at the 700-900hPa level, though convection may be strong enough under the cap to produce light sleet and snow flurries from Lincolnshire northwards. There is still scope for that to change though and the GFS version may be more conducive to heavier snow showers than the ECMWF.

In this sort of setup though there is always the possibility of some frontal snow in the long-term as others have mentioned, when we get weather systems pushing against the cold block, or maybe systems drifting up from the continent.

Edited February 15, 2013 by Thundery wintry showers

[MR EXTREMES]

can i ask any of the more experienced model watchers is the greenland heights likely at this point?

gfs is blinding at the end absolute gem amazing run.

Edited February 15, 2013 by model rollercoaster

[chris55]

180, little cold pool of -10 popping up and being dragged west, snow risk knocking on the door of the far south west.

[TEITS]

Wow what a run for N England.

http://www.wetterzentrale.de/pics/Rtavn2281.png

Most would be digging themselves out if this was to occur especially those in the E.

[fergieweather]

The GFS's forecast Skew-T graphs only go out to T+84 which isn't far enough out to gauge likely conditions during the easterly

They're freely available right to the end of each run for any lat-long gridpoint, with meteogram.

[TEITS]

Good to see the NAE at +48 supporting the 06Z GFS.

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2013/02/15/basis06/scan/pslv/13021706_1506.gif

Im going to keep my eye on this chap over the next 24hrs.

[fergieweather]

Sorry: meant to include link. We always get them direct from NOAA at usual place: http://ready.arl.noaa.gov/READYcmet.php

[DR(S)NO]

Considering a week or so ago there were "winters over" claims....I would take solace that there is very little in the models this morning to back that claim.Indeed plenty late winter weather to enjoy.