Winter Model Discussion 06Z 10/01/13>

[Josh Taliesin Gibbens]

Hello everyone . I've been following the forums for a couple of years and thought I'd join in . First off I love snow and want lots of it, but aren't the GFS charts on FI at the ranges you're talking about?

[karlos1983]

Just having a brief look over the models, looks like the GFS tries to come in line with the Euo's then, the sw seems to try to head se, albeit very slowly, then it all starts to get very messy/snowy, which I'm liking a lot!!

ECM Looks a strange transition from T96 - T120/144, but still cold so I'll take it

GEM just looks brilliant T96-T144

UKMO equally ok

GEFS reluctantly looking like its going to bow down?

So, just trying to get a quick catch up, very much game on? This is a question rather than a statement as I've not been around today.

Cheers

Karl

[rory o gorman]

Could that cause a Thames streamer?

they form in moderate to strong winds with a normally -5/6 850 temp for snow along a convergence line , The fax above shows a frontal system in slack air .

Edited January 11, 2013 by rory o gorman

[karlos1983]

Back from the pub and catching up with things. What a mood in here with the GFS "coming on board"

Of course while we've been debating which was right GFS or ECM, its worth noting that they could both yet be wrong!!!. And the last time we got agreement the GFS went straight off it. will the ECM do the same?

it's quite strange to see the "pub run" hailed as GFS behaving itself at last. I've seen cold runs in the past (though not sure on this scale) which were swamped in caution due to it being the "pub run".

But I don't want to be negative nor do I have any negative feeling. Even in the deep dark dross of modelling back in December, I could see charts that were similar to ones in 1947 before that winter arrived and i want this year to be a new 1947!

A word about streamers.....and good to see Paul Sherman posting above. My memories of 2009 were of a met office warning for upto six inches of snow to begin falling from monday afternoon. Well I'd been reading Paul's posts in here about a possible streamer, and that duly arrived on sunday evening. We had seven inches of snow BEFORE the advertised 7 inches of frontal snow promised by the Met office was due to arrive. There was very little said by the Met office, to my memory, about the streamer snow. And when the so-called big event arrived, which I imagined was going to be fantastic on top of what we already had (in Broxbourne Herts by the way) it turned out to be a mixture of wet snow, sleet and even rain which did nothing at all to top up the totals we already had.

so...if we get a significant easterly wind...it's possible that areas 20 miles or so either side of the Thames might end up with significant snow that is not widely forecast hours, let alone days, before the event. That's what a streamer is!

Already, without any verification, this has been a fantastic couple of weeks of model watching. sometimes i think it's almost more exciting to see a model deliver a run of cold and snow, then it is to see it actually get cold and snow!

If the latest runs come anywhere near verifying, this will be a winter that i remember for the GFS picking up first, The ECM coming aboard and sticking with, the GFS dropping and only coming back online very late with, and the CMA taking an absolute age to come out!

Hi Timmytour,

I know your a big GFS fan, I actually have no bias, just find it really interesting when times are like this, love your posts, always very informative, but with reasonable facts and reasoning.

I'm glad that no Model can really come out of this now with embarrassment, it has been so up and down, with all models, and (correct me if I'm wrong as I've only had 30 mins to catch up on today's action and I'm still learning) it does now look like a middle ground is looking likely, even though written off by some?

Cheers

Karl

[alexisj9]

Agreed but what has caused this sudden turn around in model output? Could someone with more technical expertise than I please give an indication of how the GFS got it wrong for a couple of days and has now backed down?

It's prety simple the GFS had the Azores high and the Scandy high link under the low presure/short wave so it could not come south east, in this latest run they link over the top of the short wave. I have no idea what caused these differences, they are quite small really but there effects as seen, make a big difference.

[karlos1983]

On a serious note, there has been major snow in the Middle East, is this a knock on effect of the ssw? That must be rare surely?

[Dave Kightley]

Alittle bit further west on the ecmwf with the warm sector then i will get excited

[Dave Kightley]

What would the Ecmwf bring for the S.W with that front Monday. Looks a knife edge to me?

[Met4Cast]

What would the Ecmwf bring for the S.W with that front Monday. Looks a knife edge to me?

Taking the chart at face value it'd probably be sleety rain for the South-West and perhaps Wales. The ECM Op is one of the milder ensembles at that point though, so we might see the colder air further West in future runs.

[Snowfan50]

What would the Ecmwf bring for the S.W with that front Monday. Looks a knife edge to me?

Yes very marginal, will probaly need colder uppers.

[Dave Kightley]

Taking the chart at face value it'd probably be sleety rain for the South-West and perhaps Wales. The ECM Op is one of the milder ensembles at that point though, so we might see the colder air further West in future runs.

That's good news then. Fingers crossed Edited January 11, 2013 by Dave Kightley

[Dave Kightley]

120h fax chart at this moment in time looks (A knife edge) but OK. 96h Should be ok for though's in Somerset

Edited January 11, 2013 by Dave Kightley

[Wilxy]

120h fax chart at this moment in time looks (A knife edge) but OK. 96h Should be ok for though's in Somerset

Is that latest fax chart.

[Zenarcher]

GME the first model run of the night agrees with the ECM,

Looks good on it.

[The Eagle]

00z GME going the way of ECM. Big change from 12z on this model.

http://www.meteociel.fr/modeles/gmee_cartes.php?ech=6&code=0&mode=1&map=0&archive=0

[Wilxy]

00z GME going the way of ECM. Big change from 12z on this model.

http://www.meteociel...map=0&archive=0

Is it a upgrade from its last run?

[MrSunshine]

Is it a upgrade from its last run?

Yes without a doubt.

[Cheshire Freeze]

Is it a upgrade from its last run?

If you like the look of the ECM 12z it is

[Wilxy]

If you like the look of the ECM 12z it is

Yes without a doubt.

Lets hope all the 00z runs can finaly see some cross model agreement, i still have those famous charts back in december from that ECM, won't post could be bad luck.

[MrSunshine]

It's all on now that is for sure, Monday night into Tuesday morning is now looking rather interesting to say the least.

[The Eagle]

Is it a upgrade from its last run?

Yes. It certainly is. Trough was going east/west last run.

[Roger J Smith]

I would say that things are looking very promising for the eventual arrival of a long, deep cold interval but this next week to ten days may just be a relatively minor skirmish between the first rather weak forces from the east and the still active Atlantic.

This map link shows what happened in the Middle East after a surge of colder air across Turkey into Syria, Lebanon and Israel/Palestine (and Egypt) ...

http://www.uni-koeln.de/math-nat-fak/geomet/meteo/winfos/synNNWWneareast.gif

Much warmer air was pushed north into central Asia and this is in turn pushing the heart of Siberian cold further north and some of that will head west now into European Russia. The -10 C surface boundary today is between Moscow and St Petersburg so anomalous cold is still well back to the east but will be gradually pushing west while weak to moderate frontal boundary events dominate weather day to day in western Europe. The trend over 2-4 weeks will likely be towards severe cold and I think the U.K. and Ireland would be wise to plan for this, but the heart of the cold spell could be almost a month away and it may dominate February more than January.

Models will continue to struggle, I believe, but I would place more credibility on those which show a boundary through Ireland and southwest England, the deeper cold will be needed to push the boundary into the Atlantic. One day here or there might see one side winning extra territory, but there won't be a severe cold spell until sustained 1030-1040 mb pressures develop somewhere in the Baltic region. When this comes, I think it may be epic.

[Met4Cast]

I would say that things are looking very promising for the eventual arrival of a long, deep cold interval but this next week to ten days may just be a relatively minor skirmish between the first rather weak forces from the east and the still active Atlantic.

This map link shows what happened in the Middle East after a surge of colder air across Turkey into Syria, Lebanon and Israel/Palestine (and Egypt) ...

http://www.uni-koeln...NWWneareast.gif

Much warmer air was pushed north into central Asia and this is in turn pushing the heart of Siberian cold further north and some of that will head west now into European Russia. The -10 C surface boundary today is between Moscow and St Petersburg so anomalous cold is still well back to the east but will be gradually pushing west while weak to moderate frontal boundary events dominate weather day to day in western Europe. The trend over 2-4 weeks will likely be towards severe cold and I think the U.K. and Ireland would be wise to plan for this, but the heart of the cold spell could be almost a month away and it may dominate February more than January.

Models will continue to struggle, I believe, but I would place more credibility on those which show a boundary through Ireland and southwest England, the deeper cold will be needed to push the boundary into the Atlantic. One day here or there might see one side winning extra territory, but there won't be a severe cold spell until sustained 1030-1040 mb pressures develop somewhere in the Baltic region. When this comes, I think it may be epic.

So you're generally going for a battleground scenario over the UK for a while before the cold eventually wins out and becomes deeper? Sounds suggestive of quite a few snow events over the next couple of weeks or so!

[Ian Suffolk]

Eyes down for the 00z! Lets hope it is consistent with the superb 18z.

[MrSunshine]

I would say that things are looking very promising for the eventual arrival of a long, deep cold interval but this next week to ten days may just be a relatively minor skirmish between the first rather weak forces from the east and the still active Atlantic.

This map link shows what happened in the Middle East after a surge of colder air across Turkey into Syria, Lebanon and Israel/Palestine (and Egypt) ...

http://www.uni-koeln...NWWneareast.gif

Much warmer air was pushed north into central Asia and this is in turn pushing the heart of Siberian cold further north and some of that will head west now into European Russia. The -10 C surface boundary today is between Moscow and St Petersburg so anomalous cold is still well back to the east but will be gradually pushing west while weak to moderate frontal boundary events dominate weather day to day in western Europe. The trend over 2-4 weeks will likely be towards severe cold and I think the U.K. and Ireland would be wise to plan for this, but the heart of the cold spell could be almost a month away and it may dominate February more than January.

Models will continue to struggle, I believe, but I would place more credibility on those which show a boundary through Ireland and southwest England, the deeper cold will be needed to push the boundary into the Atlantic. One day here or there might see one side winning extra territory, but there won't be a severe cold spell until sustained 1030-1040 mb pressures develop somewhere in the Baltic region. When this comes, I think it may be epic.

I respect your views but however I think you might be wide of the mark, expect severe conditions in the UK next week mark my words.