Winter Model Discussion 18Z 13/1/13 onwards.

[bradymk]

I think it's vital to appreciate Exeter can only be pragmatic and at this range, given model uncertainty, only run with what seems largely consensual as outcome. Anyway: it's far off in yonder given present climate of model nuance issues. We shall see.

Yes wasnt't an unexpected change given the little suport in the evolution however fax chart still hints at southerly tracking LP's as a potential outcome for sure. Also, GFS hightlighting potential for some snow to influence far SW and W parts end of the week,is this a plausible outcome Ian? Edited January 13, 2013 by bradythemole

[Cloud 10]

Well take something positive from the modification, its still a good looking chart with enough energy going se to suggest that the cold could hang on for a while longer.

Theres still a chance for some fronts to skirt with the west/sw to produce some frontal snow, theres so much uncertainty so best to really view any post 96hrs output with alot of caution.

Agreed Nick,that's still a strong block on the fax chart which will take some shifting,i think the 12z

UKMO was the Nigella Lawson run.

[Froze were the Days]

One thing I have noticed the inability for any sustained big heights in the correct place this winter (above 135mb) it just hasn't happened and we've had to rely on very 'weak' looking heights out to the north east whilst we have these sw spoilers continuing and a PV not wanting to stray away for too long from Greenland.

Edited January 13, 2013 by Froze were the Days

[karlos1983]

Yes wasnt't an umexpected change given the little suport in the evolution however fax chart still hints at southerly tracking LP's as a potential outcome for sure. Also, GFS hightlighting potential for some snow to influence far SW and W parts end of the week,is this a plausible outcome Ian?

Pretty certain they don't even look at the GFS, and who could blame them after the drab we have just seen

[LomondSnowstorm]

Can't see that happening at all, maybe towards the north but the uppers will be too high. Just by looking at the synoptic of that it's simply not cold enough.

It's unlikely to occur of course but a dominant vortex centred to the south or southeast of Greenland have given countrywide snowfalls in the past:

Certainly Arctic or Polar westerlies are one of the main sources of snowfall for western Scotland. I somehow doubt we're likely to see those kinds of charts verify though and I'd much rather have a block in place because that setup is incredibly hit and miss.

[rory o gorman]

bring on that cold zonal flow > will do much better for western ireland , thunder snow possible with some F.I charts on 18z

[Matty M]

quality nogaps tonight to finish off on a positive! very gem like!

[Cloud 10]

well i think

The GFS,ECM,UKMO, T120 PV GH SW going SSW with LP on the JS around the NA sliding round the UK into biscay at T144,

this also

lets the HP over Sc head NNW and the SW head SE into EA.

while the SSW ?

Finally FI is F1 at T 12

P.S the PPn lght at T24 due to snow one having a clue

Blimey,22 acronym's in one post.

[fergieweather]

Pretty certain they don't even look at the GFS, and who could blame them after the drab we have just seen

Yes they do and have even taken 12z into consideration for amendment to their own GM. The hallmark of good, unbiased science...!

[J10]

Lol! really you know I've only been on here 8 years, fancy that a nnw sourced in the north being cold!

You did say though that a flow west of north was not good for low lying snow and numerous snow streamer events prove that wrong.

So you going against your original comment.

[nick sussex]

It's unlikely to occur of course but a dominant vortex centred to the south or southeast of Greenland have given countrywide snowfalls in the past:

Certainly Arctic or Polar westerlies are one of the main sources of snowfall for western Scotland. I somehow doubt we're likely to see those kinds of charts verify though and I'd much rather have a block in place because that setup is incredibly hit and miss.

The key thing with that chart is the main PV east of the UK and what looks like higher pressure near the pole.

The fact you had to go back 28 years to find that chart sums up the miss part of the hit! lol

[Continental Climate]

not meaning to be downbeat but today has been a day of pretty much constant downgrades both in the short and medium terms. The only ray of light was the ukmo at 120 and ian says that has been disregarded by the met. So where does that leave us?

Another day of downgrades tommorrow and i think we can call the end to the cold spell fri or sat. What has been particularly dissapointing is the complete downgrading of our midweek easterly from something special to a calm but cold spell of weather.

I dont think the jet will undercut as people are hoping!!

Probable cause of our demise low heights around greenland and that big hunk of vortex in eastern canada.

[J10]

I dont fancy our feeble block's chances against that huge 945mb piece of vortex in the atlantic http://www.wetterzen...s/Rtavn1681.png!!

I don't fancy the chances of us getting there in the first place to the scenario forecast by GFS @ T+168. .

Edited January 13, 2013 by Jackone

[karlos1983]

Yes they do and have even taken 12z into consideration for amendment to their own GM. The hallmark of good, unbiased science...!

Ah ok, thanks for the heads up, I was led to believe from others that was not the case.

[Davey80]

Don't think the UKMO is on its own. Its kinda the same setup as NOGAPS and GEM

[BLAST FROM THE PAST]

Yes posted when came out that the UKMO at t96 would not show tomorrow what it does today at t120, the shift didn't look logical. MetO clearly watered it down a bit, and that makes sense. Overall a disappointing days runs, a cold week but that's about the jist of it from today's runs. 2c - 3c daytime temps are cold for sure but IMO a nuisance nagging temp with no real interest involved.

BFTP

[Froze were the Days]

The mighty NOGAPS/GEM and a soon to be watered down UKMO (following the FAX) against ECM and GFS - hmmmmm.

[nick sussex]

You did say though that a flow west of north was not good for low lying snow and numerous snow streamer events prove that wrong.

So you going against your original comment.

I was talking in context of the output of the GFS,yes of course a nw sourced north not a westerly circulating round a huge low stuck in the Atlantic.

I said n round to east and didn't realize I had to stipulate you couldn't have a nnw or nw. You know what I meant so stop being difficult!

[stainesbloke]

Yes posted when came out that the UKMO at t96 would not show tomorrow what it does today at t120, the shift didn't look logical. MetO clearly watered it down a bit, and that makes sense. Overall a disappointing days runs, a cold week but that's about the jist of it from today's runs. 2c - 3c daytime temps are cold for sure but IMO a nuisance nagging temp with no real interest involved.

BFTP

There will be changes, some very short term ones I'd expect so not all hope lost. Worst case it will be dry and cold like you say, I guess it will go a long way towards drying out those flood hit areas. Sunny and cold is loads better than rain rain rain IMHO.

[karlos1983]

There will be changes, some very short term ones I'd expect so not all hope lost. Worst case it will be dry and cold like you say, I guess it will go a long way towards drying out those flood hit areas. Sunny and cold is loads better than rain rain rain IMHO.

Agreed, hopefully we can start looking toward the next cold setup if things progress as discussed in here lately. That's an observation, no charts to back that up, just hours upon hours sitting in here listening to the more intelligent.

[If Wishes made Weather]

Don't think the UKMO is on its own. Its kinda the same setup as NOGAPS and GEM

This is correct I think. The idea generally - to send more energy south rather than north from the North American continent is shown in a couple of the Operation runs - and in several of the parallel runs, but as far as I can see, nothing as extreme as the UKMO GM run. Looking though again at all the models today, and the uncertainty which does seem to fire up some interesting ideas at times in FI and the semi-reliable, and then drop them, I am starting to wonder if this winter will be one that is generally cool, or perhaps cold when looked at statistically, but rather a placid one (save for the shocking flooding in the SW). Realistically, we are now seeing ideas running out to the end of the month leaving 1/3 of the winter left only to produce something less tame.

[Jason M]

Just run through the ensembles at day 5 / 6 and the opp is well supported by its ensembles this time. If GFS is to be believed tonight a gentle decline into zonality.

The heights over scandi are just a bit too far east to really do the business.

Chino, what do you make of this. It looks to me that the crazy model inconsistency is just starting to settle down and were looking towards a period of zonality to follow in say 6 to 8 days time.

Jason

[Froze were the Days]

Personally feel that BFTP has called it about right but still the possibility of some snow tomorrow in areas (NE/E) and a small window of opportunity for some eastern coastal areas on Tues/Weds and then some coldish days and frosty nights but nothing out of the ordinary in regards to cold spells.

[LomondSnowstorm]

The key thing with that chart is the main PV east of the UK and what looks like higher pressure near the pole.

The fact you had to go back 28 years to find that chart sums up the miss part of the hit! lol

Very true, it's certainly not a common 'hit' for most places!

[bradymk]

ECM ens for London are still pretty good for prolonging of the cold. http://www.meteo24.fr/fr/home/meteo-france-et-europe/passion-meteo/ensemble-de-previsions.html?eps=london not many mild members at all, mean staying at 2 or 3c throughout fcast period. Also 18z GFS Ens completely different to the 12z suite so far, hard to believe how much change there is in the short term.

Edited January 13, 2013 by bradythemole