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phil nw.

Winter Model Discussion 18Z 19/1/13 onwards.

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OK then a brand new thread to discuss the 18z GFS and other outputs such as the Ens.etc.

The cold very much still in the immediate outlook with snow to come for some.

Signs of some change maybe towards the end of next week-let`s see what the next run has in store.

Please let`s keep this thread polite and informative and on topic-any chat in the other thread or your Regionals please.

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thanks-We have been 'lucky' that the stratosphere element has developed- no doubt about it it has helped change an otherwise pony winter thus far- we have landed in zone where tropospheric reaction has been largly effected-& at no point have I said the stratosphere has No effectthe JAN CET to the 15th was 5.6C - Quite a bit over average, the CURRENT cold spell has just got us down to average- at 4.1c ( within 0.1c)CET run over 7 days is 0.6 (11th-18th January 2013: 0.6C)- Which is noteworthy - not exceptional-The point im making is the strat has had a large warming, IF we go out this week back into a mild regime then with one of the best warmings we could have its only really made a mediocre difference...- ( remember 4 weeks of CET is made up by some ups & down & the average is ~ APPROX 10 snow days a WINTER MONTH)so when I hear people harping on how wonderful it is to see a couple of snow events in close succession- so what- thats the NORM-Perhaps when forecasting as a whole for the UK & winter months- we should have adopted Ians browns approach & assume anything can go wrong for us- because it 'usually' does...-S

Good old murphys law always there to give a helping hand. I have to agree to some extent considering how north we are in terms of latitude things should be a whole lot colder but there not. This has been a cold spell I will remember but its not the worse I have seen 1982 is one I remember to be a million times worse. But we have got to used to winters being mild and when a snap does come along it makes it seem much worse than it really is. I am hoping Feb does bring an awsome setup just to break away from boring adlantic driven weather. in winter we love the Northern Blocking, and in the summer we prey for spanish plumes and the same theories and arguments break out. I am trying really hard to put everything thats said in this forum to good use and experimenting with my own ideas. Sometimes its made harder by toys and prams but thats what happens when you put a lot of high energy deep thinkers together in a room. Personally I like everyones opinion may I agree with it or not. My previous question however has still not been answered.

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Been following this site for years, can't read an ECM from a GFS but when Winter starts i come on this model thread in the hope that i might once again see the experts predicting that we are on of the verge of another 81 Winter, i really thought this time having read all the comments about the Strat that this was it, we were on the verge of something special, i have to agree with SM, many posts even by the senior peeps on here were massively ramped, yes it's certainly an improvement on recent years but God how difficult is that, is this the best we can produce now in this country even when all the elements are in our favour ! Still wait in hope that some of the more extreme models may come to fruition but i really feel that we need to see a major change in world weather patterns to experience the winters we had had in the 70's and 80's, lay mens point of view,

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The latest 6-10 day NOAA forecast anomalies

post-2026-0-26576700-1358631349_thumb.gi

no real surprises based on recent outputs.The troughing across the Atlantic a little further north but no sign of any rising heights from the south.A cool looking cyclonic setup with some height anomalies showing over the pole.

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If we see colder than average conditions last until Thursday which looking at the models is certainly possible then here in the north east we will have had nearly two weeks of cold weather and snowcover for about ten days. Certainly no Jan or Dec 2010 but certainly not our usual winter weather. I would class it as a good cold spell.

I'm hoping we will be on the right side of marginal on Monday which will add to our existing snowcover of around 20cm.

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A bit parky over the southern snowfields - the forecast here must be as close to as cold as Devon has got?

post-4523-0-28996800-1358631667_thumb.pn

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The latest 6-10 day NOAA forecast anomalies

post-2026-0-26576700-1358631349_thumb.gi

no real surprises based on recent outputs.The troughing across the Atlantic a little further north but no sign of any rising heights from the south.A cool looking cyclonic setup with some height anomalies showing over the pole.

so what you mean by height rises is preassure , so height preassure rises to north force jet down, and hight rises to south force it north yes. I understand effect of jet going south what happens when it goes north?

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Blimey, few chill pills needed tonight spiteful.gif

Anyway, just looked through tonights posts and have concluded its all over bar the shouting. Just to clarify things in my own mind I thought i'd run through the charts myself. You know, just in case amongst the toy chucking something had been missed ph34r.png

So lets run down tonights charts pop pickers. All at day 5, as obvoiusly with the cold spell coming to an end they must all show similar as otherwise it would just be plain daft to chuck in the towell wouldnt it!?

So.....

GFS

http://www.meteociel...&ech=120&mode=0 (obv about to change as 18Z rolling out)

ECM

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

METO

http://www.meteociel...=120&carte=1021

GEM

http://www.meteociel...&mode=0&carte=0

JMA

http://www.meteociel...?ech=120&mode=1

BOM

http://www.meteociel...&mode=0&carte=0

NOGAPS

http://www.meteociel...&mode=0&carte=0

So, Atlantic will be back with us next weekend??? whistling.gif . Good luck to anyone who can assume that given the above (and the ensembles were not exactly in full agreement at day 5)

Jason

Edit: CMA http://www.meteociel.fr/modeles/cmae_cartes.php?&ech=120&mode=0&carte=0

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so what you mean by height rises is preassure , so height preassure rises to north force jet down, and hight rises to south force it north yes. I understand effect of jet going south what happens when it goes north?

2 things can happen when this happens:

1)High pressure builds over the UK which means we will be in dry, clear and warm weather with the NW seeing rain and windy conditions as low pressures 'bump' into the high which then get deflected NE.

2) Or it rises but then gets flattened by an incoming low from the Atlantic which means we will be in wet and windy weather otherwise known as zonal and can be real nuisance as this type of pattern is hard to get out of eg Winter 2011.

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Blimey, few chill pills needed tonight spiteful.gif

Jason

No CMA included in that breakdownsmile.png ...but you included NOGAPS, BOM and JMA

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No CMA included in that breakdownsmile.png ...but you included NOGAPS, BOM and JMA

Oversight correctedgood.gif

Thats showing an Atlantic breakdown (not!!).

It may happen, who knows, but thats really the point at this stage and thats even before Shannon Entropy does her stuff!

Jason

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A bit parky over the southern snowfields - the forecast here must be as close to as cold as Devon has got?

post-4523-0-28996800-1358631667_thumb.pn

The GFS temp charts are way too cold for the overnight periods don't you think? Take the max temp chart for 9pm this evening - it has -3C across the SW while currently we have obs showing 0C to +1C!

post-1052-0-47632200-1358632402_thumb.pnpost-1052-0-67606300-1358632364_thumb.gi

By 06z it's down to -5C, that's unlikely to happen under cloudy and windy conditions:

post-1052-0-19854800-1358632516_thumb.pn

But tomorrow night's is just taking the pee!

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so what you mean by height rises is preassure , so height preassure rises to north force jet down, and hight rises to south force it north yes. I understand effect of jet going south what happens when it goes north?

Yes Height rise or higher pressure at 500hPa David-on these charts these forecasted areas where we can expect lower(blues)or Higher(pinks) than average.

If the jet goes north of the UK it means theres high pressure to our south with low pressure to our north in basic terms.In that case we would get a westerly type of setup with winds off the Atlantic and milder weather.

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2 things can happen when this happens:

1)High pressure builds over the UK which means we will be in dry, clear and warm weather with the NW seeing rain and windy conditions as low pressures 'bump' into the high which then get deflected NE.

2) Or it rises but then gets flattened by an incoming low from the Atlantic which means we will be in wet and windy weather otherwise known as zonal and can be real nuisance as this type of pattern is hard to get out of eg Winter 2011.

That explains everything, so that what zonal means. Adlantic is like a women and a bull in a china shop huh ;) I did see mentioned way earlier about a scandi vortex and a canada vortex having some sort of mini battle and we hope scandi one wins, why would we want this. From what I have understood canada at the moment is starting to inject more energy into the jet sream which in turn is adding more preassure on the block to cave in. So if the scandi one wins what happens further down the line with regards to canada and the jet. This is gripping stuff

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The latest 6-10 day NOAA forecast anomalies

post-2026-0-26576700-1358631349_thumb.gi

no real surprises based on recent outputs.The troughing across the Atlantic a little further north but no sign of any rising heights from the south.A cool looking cyclonic setup with some height anomalies showing over the pole.

So what that chart is showing then, high preassure is building +150 in north pole, and falling sharply in the adlantic (which you can see the 950mb Low sitting there) and its slowly starting to sink into greenland which is what we really want to see yea? so the more the red starts to filter over greenland the better, and we want more blues to the south of the UK. So in laymans terms we want that mega low to sink to our SE into france etc which would throw jet stream south, and introduce VERY strong East winds as it passes to our SE. I would imaging they be gale force to with a LP that low.

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The GFS temp charts are way too cold for the overnight periods don't you think? Take the max temp chart for 9pm this evening - it has -3C across the SW while currently we have obs showing 0C to +1C!

post-1052-0-47632200-1358632402_thumb.pnpost-1052-0-67606300-1358632364_thumb.gi

By 06z it's down to -5C, that's unlikely to happen under cloudy and windy conditions:

post-1052-0-19854800-1358632516_thumb.pn

But tomorrow night's is just taking the pee!

A little - it will be cold and the GFS forecasts a col with moderately low heights, thin clouds and little wind in that region -it will be interesting to see the mornings lowest temps, Nick.

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http://www.meteociel...&mode=0&carte=0

The fat bird Shannon Entropy has yet to pick up the Karaoke mic.

http://www.meteociel...=144&carte=1021

But is stood at the bar, waiting to pounce with Pina Colada in hand.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=192&mode=0

And at the very last minute Nigel, Shannon's ex boyfriend has dragged her from the pub kicking and screaming.

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Wish everyone would stop stressing about what the charts a showing this comming friday/saturday. ENJOY the here and now!! its what we have been waiting for is'nt it? For instance we have

tomorrows snow event for the south east am and north east pm..........

18_21_preciptype.png?cb=306

then we have another snow event for the south west monday night/ tuesday morning spreading into the midlands, lets discuss this instead!!!

18_57_preciptype.png?cb=306

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13*C according to BBC next weekend into the new week/month. Balmy and mild. On other accounts London could hit -8/-7/-7 and -6*C on respective dates at coldest next weekend into the new week/month.

Yeah right! Being honest, I can see the Atlantic winning but not the mild crap we are expecting. CFS and ECMWF are on the money with Greenland height rises post 240 hours. The effects of the SSW will likely ware off, and what beholds will likely be the way the synoptic's and ensembles predict in similar vain to November/December 2010.

I don't think it will be till mid February till we really see those Greenland heights go for it...

February is the coldest month of winter, snow is more likely during Easter (March/April) statistically. So in that case we have 1.5 months of Winter left, and 3 months of severe weather to be had... :p

npsh500.240.png

cfsnh-0-240.png?06

cfsnh-0-282.png?06

cfsnh-0-390.png?06

Mid month Greenland height rises??

cfsnh-0-648.png?06

cfsnh-0-696.png?06cfsnh-0-714.png?06

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A little - it will be cold and the GFS forecasts a col with moderately low heights, thin clouds and little wind in that region -it will be interesting to see the mornings lowest temps, Nick.

Notably low dewpoints as well -Rtavn3610.png

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Wish everyone would stop stressing about what the charts a showing this commimg friday/saturday. ENJOY the here and now!! its whst we have been waiting for is'nt it? For instance we have

tomorrows snow event for the south east am and north east pm..........

18_21_preciptype.png?cb=306

then we have another snow event for the south west monday night/ tuesday morning spreading into the midland, then discuss this instead!!!

18_57_preciptype.png?cb=306

I hope you dont mind, I am discussing end of the week as I am learning a massive amount with the questions I am asking as its very imformative. I know there is lots to come for us next week mate smile.png even if breakdown does happen I want to know why thats all.

Model discussion, so I am discussing the models ok in FL tho but still interesting

With regards to the south and east event, I looked at the charts and one a few of them the Low never really leaves france it comes much further west to sit over bristol.

http://www.meteociel.fr/modeles/ecmwf.php?ech=48&mode=1&map=0&archive=0

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Interesting run at T84 even. Charts look the same but Arctic high seems to be getting stronger and more dominant with every run, I think we are now starting to see the phase begin where deeper prolonged cold could be on the agenda, I don't think in the long run for cold it would have to be a bad thing if that big low at T84 smashes through, will leave more room for potential height rises over Greenland.

With regards to that deep Atlantic trough, I've not often seen this with such cold air surrounding it, could is possibly make it across the Atlantic with cold uppers still entwined in it? That's of course assuming eventually it breaks through.

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Just a quick point regarding CET and snow day averages and how it's taken an SSW bring about changes towards what might be considered a normal winter - this may well be that an SSW is also a feature of a normal winter, not some special situation.

As has been looked at on the strat thread, combining the work from two researchers, Cohen and Martineau, gives a list of 55 SSW in 61 winters since 1952. Ten of these were the second SSW of the season, which leaves only 16 winters without a full SSW - and this list may not be exhaustive and there are further minor warmings to take into consideration.

Nobody claimed that an SSW guaranteed another 1962/3, it doesn't even guarantee cold, but it happens in far more winters than it doesn't so may clearly go some way to make up what is considered the average winter conditions.

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Been following this site for years, can't read an ECM from a GFS but when Winter starts i come on this model thread in the hope that i might once again see the experts predicting that we are on of the verge of another 81 Winter, i really thought this time having read all the comments about the Strat that this was it, we were on the verge of something special, i have to agree with SM, many posts even by the senior peeps on here were massively ramped, yes it's certainly an improvement on recent years but God how difficult is that, is this the best we can produce now in this country even when all the elements are in our favour ! Still wait in hope that some of the more extreme models may come to fruition but i really feel that we need to see a major change in world weather patterns to experience the winters we had had in the 70's and 80's, lay mens point of view,

I don't think the senior people on here massively ramped anything. They simply gave their opinion and explained the potential. It's other people who have taken those posts and ramped them to a point where I think some people were expecting something akin to The Day After Tomorrow. Unfortunately, if you come on here hoping to see something then whatever the outcome is you will always have a subjective view of it rather than an objective view. That tendency for a lack of objectivity is shared by a number of other members here and that filters through to their analysis. So we get the slightly childish winter is over posts a few weeks ago despite the fact we were only a month into it and obviously we now have a cold spell bringing some decent snow and cold to most of us. From what I can see the senior people on here don't fall into that category.

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Let`s keep on topic guys please.

If you want to widen discussions to other topics outside of model outputs please use the relevant threads.

Thanks.

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