General Model Output Discussion Tuesday December 22Nd:

[pyrotech]

980mb Azores Low anybody, with 1055mb Greenland High? Can we bank this run! :lol:

Two to three weeks ago we were all talking about the cold spell in fi. Well it arrived and what we watched prior was a consistant trend towards the cold. Lets be totally honest the models, GFS , ECM and later the meto all pretty much did a good job at detecting it. There was of course the last minute variations and corrections. Then there was the percipitation, like many said lave that till 48 hrs out max. So most of the country had some snow, all were cold and some major disruption to travel. 80s style !! So used to downgrades in cold its great to see it now in mild. This wek has seen the mild put back and less intense each day.

So what do we see ahead? Another trend again for cold. Yes less cold in the South for a time, but the trend is for the cold to return to all. Anything beyond xmas day is going into Fi in my opinion due to the very complx situation. BUT like three weeks ago the trend is picking up momentum. Assmbles keep the cold, GFS and ECM although different variations. i can not think of a better way for winter to start and in terms of real cold the winter has only really just began. Trends can and do go wrong but i find the trends much better than on model on its own or just one run.

We can all talk about Fi but in regards to trends we all just watched GFS show this from 240hrs out, Truly Fi, and except for timing and slight technical differences it was pretty much on the ball.

Both GFS and ECM look amazing tonight and a snow fest could be due around start of 2010, now i need to see the trend continue for a few more runs.

Hopefully Santa will bring you all what you want, if not i think the weather will.

[Liam J]

mouth watering charts to feast your eyes on, instead of turkey!! xmas day and i'll be waiting for all the model outputs!!! bring on the snowstorms!!

[Guest North Sea Snow Convection]

The 18z GFS brings another set of relatively marginal situations along where the northern boundary of the lows are. Although of course there would still be large anounts of wet snow

A way to go before we see anything like the end of Dec 78 blizzard that had -15 850's knocking on the door in the wake of the blizzard on New Years Eve and then New Years day 1979.

I remember that remarkable blizzard like it was yesterday lol! My hair was frozen with inblown powder snow and ice to the hood of my coat whilst coming home from a party, and the snow was blown clear of the roads that were bone dry and the drifts were piled against walls and any other objects where the gale force north easterly wind allowed. Icicles hung like sharp teeth from the illuminated street lamps. I exaggerate not!

Edited December 22, 2009 by North Sea Snow Convection

[TEITS]

Feb 1978 not Jan/Feb 1979

Oh right cheers for letting me know. I knew it was around that period but couldn't be certain.

I see some are already worrying about missing the snow. For starters don't worry at the moment because we don't even know if will even occur. The models have certainly upgraded the prospects between Xmas and New Year but I doubt this is the end of the changes. I see the BBC are less inclined to mention turning milder in their forecasts compared to yesterday.

Like I said to Tamara yesterday our recent cold spell could be the starter before the main course. I just hope im right and it wasn't the dessert.

[damianslaw]

Increasing signs that any warm up is looking like a very temporary affair and for Scotland no real warm up looks on the cards - the low pressure tracking in later christmas day and into Boxing Day holds the key, it is increasingly being progged to track further and further south leaving most of the north on the poleward, southern and central areas are likely to see a thaw and temps recovering to near average but for the north only a very short lived temporary thaw on Boxing Day I say and never on high ground.

Beyond Boxing Day, we maintain a negative AO and NAO combination and with mid atlantic ridging possibly setting in a blast of very cold arctic northerly air is looking very plausible.

Still out of the reliable timeframe but the synoptics this evening are looking very condicive for the very cold theme and snowy theme to continue next week - blocking over Greenland is not going away, I've long said our best winters are when blocking is strong over Greenland then we just get northerly and easterly reloads and low pressure tracking on southerly course with undercutting - even chances of polar lows, long may the blocking remain in situ, late Dec is often a pivotal point in the winter and trends are often set here and now when the atlantic is traditionally at its strongest.

[snowlover2009]

SL - those charts are a lifetime away considering how early FI has become. as much chance of leeds being the battlefront as the south, the midlands, scotland or indeed Paris.

I was just talking about the actual 18z thats all. i just wondered would that actually bring blizzards and severe weather here in leeds, i just wouldn't want to be on the borders of something very spectactular of what some people have never seen in their lifetime and then miss out on it.

[ribster]

Some real eye candy again on the 18GFS, in fact if it were to verify post T+168hrs (but clearly there's no guarantee that it will) even this area culd get a proper easterly blizzard, followed by a bitter northerly. Probably as good as it gets synoptically, but still a very long way off given the current set up.

Point taken - no guarantees, but the GFS conjured this up on the 2nd Dec (a full 15 days away), and if not mistaken it wasn't too far off the mark?

Edited December 22, 2009 by ribster

[TEITS]

mouth watering charts to feast your eyes on, instead of turkey!! xmas day and i'll be waiting for all the model outputs!!! bring on the snowstorms!!

If the model runs continue like this into tomorrow and xmas eve then I shall be serving egg & chips to my family on xmas day.

Amazing to think that this is +144.

http://www.wetterzentrale.de/pics/Rtavn1441.png

[yamkin]

Some real eye candy again on the 18GFS, in fact if it were to verify post T+168hrs (but clearly there's no guarantee that it will) even this area culd get a proper easterly blizzard, followed by a bitter northerly. Probably as good as it gets synoptically, but still a very long way off given the current set up.

You seem to be very negative

Three top models are gearing up for a further colder period. We all know things can change, so we shall all monitor the models in the coming days

[snowlover2009]

The 18z GFS brings another set of relatively marginal situations along where the northern boundary of the lows are. Although of course there would still be large anounts of wet snow

A way to go before we see anything like the end of Dec 78 blizzard that had -15 850's knocking on the door in the wake of the blizzard on New Years Eve and then New Years day 1979.

I remember that remarkable blizzard like it was yesterday lol! My hair was frozen with inblown powder snow and ice to the hood of my coat whilst coming home from a party, and the snow was blown clear of the roads that were bone dry and the drifts were piled against walls and any other objects where the gale force north easterly wind allowed. Icicles hung like sharp teeth from the illuminated street lamps. I exaggerate not!

i bet its the drifts after the the blizzards what make events like them spectacular too, just seeing how they are and look. i have seen drifitng but never anything like how you describe, i can just imagine massive amounts of snow being blown against walls

[casparjack]

Completely off topic i know, but talking of one of the south west posters - what's happened to Jemtom this winter?- last year he was a very frequent poster. Anyone know?

...melted in his blowtorch?

[Guest North Sea Snow Convection]

i bet its the drifts after the the blizzards what make events like them spectacular too, just seeing how they are and look. i have seen drifitng but never anything like how you describe, i can just imagine massive amounts of snow being blown against walls

You don't forget great experiences like those. No taxis or anything that night - you just walked home with your friends for safety and enjoyed the experience!

Don't want to go off topic - but that night just before NY 1979 and the snow during Jan 87 take some beating!! Although I saw much more snow in terms of depth (several metres) skiing in Austria,

[snowlover2009]

You don't forget great experiences like those. No taxis or anything that night - you just walked home with your friends for safety and enjoyed the experience!

Don't want to go off topic - but that night just before NY 1979 and the snow during Jan 87 take some beating!! Although I saw much more snow in terms of depth (several metres) skiing in Austria,

what were temps like on that night? gosh, i cannot imagine drifts getting up to my second floor windows, it probably did do back then, but nowadays it would be just unreal, heres hoping for the rest of this month and next week. i know its a random question too lol, but how long would it take for a drift to get as high as a second floor window. does a drift usually mean most of the snow gets blown up against the wall or can it mean snow being blown by the wind in the air and crashing into wals and creating the drift. if you get my drift lol

[nick sussex]

GME is generally an excellent model out to T+132hrs (it is German after all) and GEM has proven time and time again not only to spot trends but also provide some of the most reliable modelling in the T+120 to T+192hr timeframe. Therefore with respect I am not as you suggest using the least reliable charts to prove a rather baseless point - far from it in fact.

In terms of these two models the gem has improved over the last year but the gme is cannon fodder! it's only to be used in times of emergency when all the rest show mild mush and it shows something alot better!

Tonights gem at 144hrs is actually quite close to the ukmo and would still lead to something colder, however we're still along way from being confident of a return to some very wintry weather after the mini less cold blip, i always like to remain cautious until i see all the major hurdles removed, its a simpler transition however than the recent easterly and i'll be happy to start shovel watch at T-96hrs!

[Guest North Sea Snow Convection]

what were temps like on that night? gosh, i cannot imagine drifts getting up to my second floor windows, it probably did do back then, but nowadays it would be just unreal, heres hoping for the rest of this month and next week. i know its a random question too lol, but how long would it take for a drift to get as high as a second floor window. does a drift usually mean most of the snow gets blown up against the wall or can it mean snow being blown by the wind in the air and crashing into wals and creating the drift. if you get my drift lol

I remember the local radio station saying it was -4C when I got home around 2am. That is excluding the windchill factor of the gale force winds!

Regarding the current models, perhaps this month is just the appetiser before the main course delivers something like that in the New Year??

Edited December 22, 2009 by North Sea Snow Convection

[Frosty.]

Final word on the 18z run..simply put, this has to be the most wintry gfs run ever, it must be for GP to comment on an individual run and the thought of powder snow blowing around would make the perfect late christmas present for me and most of you.. :cold

[Upgrade]

[This run is so extreme it would lead to widespread severe blizzards which would dwarf what most of the uk has seen so far.

I'm in paradise!

It is so many years since the UK experienced widespread severe blizzards - this might just be the year.

The charts did show "armageddon" scenarios leading up to this cold spell - but i would say that , in itself, this cold spell has been rather out of the ordinary with what we've experienced in the past decade or so. i've had more days with snow lying here in my part of London in 2009 than in all of the previous 10 winters put together. it could get even more extreme as we head into winter "proper".

Just look at the extent of snowcover across Europe at the moment. Large scale cold pooling. It could be a cold snowy winter to come - and the charts are showing the way!

(ramp over)

[NorthNorfolkWeather]

If the model runs continue like this into tomorrow and xmas eve then I shall be serving egg & chips to my family on xmas day.

Amazing to think that this is +144.

http://www.wetterzentrale.de/pics/Rtavn1441.png

Hi Dave, I think FI starts at about T96, but that's good for a T144 chart.

How about this for the GFS T216? But as I say FI starts early, but if this happened it would be both and

Sorry, but too many 'buts'

Edited December 22, 2009 by NorthNorfolkWeather

[snowlover2009]

Hi Dave, I think FI starts at about T96, but that's good for a T144 chart.

How about this for the GFS T216? But as I say FI starts early, but if this happened it would be both and

Sorry, but too many 'buts'

it really isn't that far out when you think about it, very extroidinary, if it was in the low res i wouldn't be as excited, but that would be hell on earth much of england and wales

[Nick.F]

i bet its the drifts after the the blizzards what make events like them spectacular too, just seeing how they are and look. i have seen drifitng but never anything like how you describe, i can just imagine massive amounts of snow being blown against walls

That particular storm was unbelievable, in some exposed lanes close to the village where I grew up, the snow blew through hedges and some drifts were well above adult head height. I remember standing with some friends inside a hollowed out snow drift.

Sorry way off topic, some amazing reminiscences popping into my head. I will shut up now.

[snowlover2009]

That particular storm was unbelievable, in some exposed lanes close to the village where I grew up, the snow blew through hedges and some drifts were well above adult head height. I remember standing with some friends inside a hollowed out snow drift.

Sorry way off topic, some amazing reminiscences popping into my head. I will shut up now.

in 63 drifts were recorded up to 20 ft. absolutly unbelievable. would the wind pick up and blow the snow off the ground and then into drifts, or would the snow just come from the sky and drift like that?

[Stu_London]

in 63 drifts were recorded up to 20 ft. absolutly unbelievable. would the wind pick up and blow the snow off the ground and then into drifts, or would the snow just come from the sky and drift like that?

Probably a combination of them both. The best drifts I saw were about 12 feets in Teesdale in February 1991. Was like driving through a snow tunnel after the ploughs had cut through them

On topic

A surreal 18z there. From a purely IMBY point of view, things could do with being about 100-150 miles further south to keep the whole country cold. A lot of snow-thaw-snow-thaw-snow-thaw for the Midlands southwards on this run.

[cold snap]

Increasing signs that any warm up is looking like a very temporary affair and for Scotland no real warm up looks on the cards - the low pressure tracking in later christmas day and into Boxing Day holds the key, it is increasingly being progged to track further and further south leaving most of the north on the poleward, southern and central areas are likely to see a thaw and temps recovering to near average but for the north only a very short lived temporary thaw on Boxing Day I say and never on high ground.

Beyond Boxing Day, we maintain a negative AO and NAO combination and with mid atlantic ridging possibly setting in a blast of very cold arctic northerly air is looking very plausible.

Still out of the reliable timeframe but the synoptics this evening are looking very condicive for the very cold theme and snowy theme to continue next week - blocking over Greenland is not going away, I've long said our best winters are when blocking is strong over Greenland then we just get northerly and easterly reloads and low pressure tracking on southerly course with undercutting - even chances of polar lows, long may the blocking remain in situ, late Dec is often a pivotal point in the winter and trends are often set here and now when the atlantic is traditionally at its strongest.

Agreed.I believe a good blocking will lead us into a positive January.

And January has become the month.that has not been to kind to us in previous winters.

Gfs 18z Is superb.the potential just keeps coming.i do believe one thing this is a great chance.these charts may never show again for some time .we need to pull this off.

I never seen so much potential in any winter from greenland.18z shows you how it is done

Edited December 22, 2009 by cold snap

[rich1]

You seem to be very negative

Three top models are gearing up for a further colder period. We all know things can change, so we shall all monitor the models in the coming days

good output today, though personally would like everything as far south as possible

Edited December 23, 2009 by shuggee

[mesocyclone]

Hi all,

Thanks in advance if someone can answer this.

Only out to t12! Estofex has a storm warning(not level 1) for almost the whole south coast tomo. BBC said the showers from the coast would drift inland. Currently -5.6 here at last look with snow laying for the 6th day in a row.

Whats the chances of some heavy snow showers for some of the south thats been hit? Is it going to warm up that much?

Thanks

Meso