Model Output Discussion - Tuesday 20:25 -->

[Leigh]

Thanks John & Rob K.

I will read your blog John thanks for the advise.

[Dingwantssnow]

Pub run just starting??? Still getting my head round the timings

[NorthNorfolkWeather]

if this warm wave happens and it causes the polar vortex to collapse what are the implications for the winter could we end up with a 1963 or 1947 winter any ideas guys

Hi Leroy,

From my (limited) knowledge, anything is possible, but I think the odds would have to be stacked heavily against it. If you look at the models, even now they are forecasting a 'green' christmas for most of us, not a white one, but there are some real expets on this forum, Glacier Point, John Holmes and loads of others.

From Glacier Point's post earlier on, we may have reload of wintry conditions, but the UK is more often than not a battleground, and often the mild Atlantic wins. But historically, January and February are the coldest months and to get the sort of cold currently being forecast is unusual, if not unprecedented.

The best thing I find about this forum is that you can ask as many questions as you like ( as long as they are reasonable sensible)

Edited December 8, 2009 by NorthNorfolkWeather

[Tim Bland]

So far 18z is a major downgrade......Only kidding!! My gut feeling is this will be a stonking run and more in line with the 12z ensemble mean.

Edited December 8, 2009 by Tim Bland

[Optimus Prime]

12z chart of the day for me. Lots of heavy snow (mostly rain/sleet to the south) but the north would definitely be pasted.

[Paul]

Pub run just starting??? Still getting my head round the timings

Yep - 18z (pub run) starts at 21:30 ish and finishes at about 22:40

All the run times are on the viewer page too:

http://www.netweather.tv/index.cgi?action=nwdc;sess=

[Devon-Nelly]

I think the GFS is trying to implement what GP is and has been suggesting although i don't think its quite there yet.

My thoughts are that a half way point between ECM and GFS maybe a possible outcome or a starting point with the lows coming from the south west but perhaps more slowly.

Just a thought lol

Edited December 8, 2009 by Devon-Nelly

[PersianPaladin]

Perhaps the deep solar minimum we are in is now starting to become the main driver re strat warming, more southerly jet,northern blocking. The LAG effect maybe upon us

QBO, MJO and other tropical-convection wave-related cycles and feedbacks have much more to do with these events than solar minima. I'd suspect the lag-time for solar minima-influenced flow patterns would also be longer.

Edited December 8, 2009 by PersianPaladin

[bluearmy]

the extended ecm ens posted above show the shortwave at the end of the op run to be an outlier. (not a surprise given the range). however, if we get a brisk ne flow and the uppers are below -8c, i think we could see a fair amount of snow on the eastern side. the jet looks to be progged a bit too far south to deliver frontal precip so we're going to have to rely on the strength of any onshore flow to generate showers. given that the north sea is a little on the warm side at the moment, we do need uppers below -8c IMHO, unless the flow is very fast in which case there will be less modification. all very uncertain at a range beyond a week but the nwp is very bullish about the block over iceland/greenland and the southerly jet.

http://www.meteociel.fr/modeles/naefs_cartes.php?ech=192&code=0&mode=0&map=1

NAEFS continue to paint a phenominal picture beyond T240. remember that 50 ensemble runs from two different models should be returning to automatic pilot beyond t240. the jet stays well south and strong so as time passes, even if we miss the snow train to our south over europe, eventually, it will come our way and with the continent snowbound, any breakdown will be a good one.

seems a crazy time model watching and everyone seems to be waiting to fall off the rollercoaster.

Edited December 8, 2009 by bluearmy

[Harsh Climate]

http://www.wetterzentrale.de/pics/Rtavn781.png

The low over NE scandanavia is deeper and looks better than on the 12z. Expect the cold to be drawn in quicker and further west than previously...

Edited December 8, 2009 by Jed Bickerdike

[Fozfoster]

was that a pin drop?

[chionomaniac]

QBO, MJO and other tropical-convection wave-related cycles and feedbacks have much more to do with these events than solar minima. I'd suspect the lag-time for solar minima-influenced flow patterns would also be longer.

The solar min and easterly QBO do help facilitate this pattern - see GP's posts on first page of strat thread.

[David-kig]

looking a little further west up iceland other then that not much difference so far

[Barb]

I'm liking the look of this run... more cold to our east and a better feed already. Going to be a good un I think.

Edited December 8, 2009 by Barb

[Buzzit]

Hi All

I for one would like to give thanks to the mods on here - it cant be easy !

Can I make a suggestion that this thread (and previous model output threads from the last couple of weeks)

get pinned so that over time we can all pour through the discussion and get a really good idea of what is and

has occurred ? As the synoptics etc are so unusual as compared to recent years I feel it would be a fantastic

teaching tool in due course if someone can analyse and build some sort of teaching model after the event

Just a thought - thanks everyone for your posts !

Edited December 8, 2009 by Buzzit

[Optimus Prime]

Perhaps a more west displaced high this time around?

[kold weather]

ECM ensembles look decent enough to me, a pretty good support for a cold shot, though the 12z ECM maybe a little on the cold side for the intial shot. It doesn't get hardly any support for the LP situation at 216-240hrs however it has to be said, but still that was a rather extreme looking chart.

18z STILL taking a different route for the shortwave, so may not end with the full monty this run either but we will see.

[Duane S.]

Much better ridging than the 12z up to +102

[The Eagle]

That shortwave to the East of Greenland at 96hrs which we need is actually being a pain in the neck.

[DAVID SNOW]

QBO, MJO and other tropical-convection wave-related cycles and feedbacks have much more to do with these events than solar minima. I'd suspect the lag-time for solar minima-influenced flow patterns would also be longer.

As with all things ......... time will tell.

sorry mods a bit off topic, perhaps

[Geordiesnow]

Still a bit like the 12Z but it could be a slightly better because the Arctic high is more of a feature and the lower heights to our South is a bit further North.

The shortwave to the east of Greenland could still cause a problem or two.

Edited December 8, 2009 by Geordiesnow

[kold weather]

The ridging doesn't matter remember, if you want a cold plunge you *must* have the shortwave diving down south rather then getting delayed, at the moment this is still closer to the 12z run then the 06z run.

However the easterly is being steadily upgraded for the weekend as well, could be a cheeky one...I suspect whats happening is the intial ridging is actually too strong and shunts the shortwave too far north, so whilst we get a slightly colder easterly flow, the easterly flow further out lacks any real kick to it.

[Tim Bland]

Looking ok to me up to +90 The pesky low in sw Greenland area has gone and HP stretching quite far north. Expecting a good run

[Harsh Climate]

The high over britain is further north, that has to be a good thing

[snowmadchrisuk]

Hi All

I for one would like to give thanks to the mods on here - it cant be easy !

Can I make a suggestion that this thread (and previous model output threads from the last couple of weeks)

get pinned so that over time we can all pour through the discussion and get a really good idea of what is and

has occurred ? As the synoptics etc are so unusual as compared to recent years I feel it would be a fantastic

teaching tool in due course if someone can analyse and build some sort of teaching model after the event

Just a thought - thanks everyone for your posts !

You can still access the previous model threads right back to the October, just click on winter disscusion and you will find there are 3 pages of threads with all the old model threads still on there.