Winter Model Discussion - Cold Hunting -12Z 06/01/13

[Southender]

Its getting a bit messy in here. Toys all over the shop!

One set of runs does not mean game over for goodness sakes. Its just another "potential" outcome.

In this situation with the strat behaving differently than the norm, we are going to get wild swings for and against cold. Lets just sit back and see how things play out next week.

Far too early to be chucking towels in just yet. We have been here many times and yes more often than not we miss the boat. But now and then we get lucky.

We have to remember we are a tiny rock at the edge of a large warm pond. It has and always will be difficult to get a real potent wintry spell here. But it does happen every now and then.

Forget next weekend. Its the following weekend and beyond which hopefully will deliver. Until then just relax a bit and pray!....

[TEITS]

Lets be honest here for the 11th/12th Jan only a few runs have suggested a cold, convective E,ly. Now obviously some runs have been better i.e 0Z ECM but looking at the differences between the GFS/UKMO/ECM you cannot assume these charts aren't subject to change. We could well see a change to a more colder E,ly flow at this timeframe because +120/144 is always subject to change. When the model output becomes consistent is from +72. This is why many of us say getting an E,ly at +72 is the holy grail.

So my view hasn't really changed. A possible E,ly next weekend although what type of E,lys is uncertain, followed by a brief less cold period which could then be replaced by a N/NE,ly as blocking develops NW.

Lets not make the mistake of assuming the less promising runs are right because of past disappointments. This is flawed meteorologically speaking. Who knows maybe recent ECM runs have been too extreme but maybe tonights is the opposite. I shall await more output before I make knee jerk statements and spit my dummy out of the pram.

[bradymk]

ECM brings some dry and cold weather with some low surface temperatures but no upper air cold for snow if that is what you're after. More runs yet again needed but moving away from very cold in the shorter term but beyond that still has huge potential. The week after next for me is our biggest chance. A big cooldown though compared to the weather of late. Lets hope the SSW today has messed with the models ECM ens were good this morning and especially longer term so lets hope they show something similar tonight. A northerly developing at the end of the run but can't really say anything if they cant fully agree at +120

Edited January 6, 2013 by bradythemole

[Cecil Hogmanay Melchett]

Poor ecm,is a midlat high the best we are going to get?

Not liking the trend to relocate the PV across Greenland this evening.

[ronan]

Steve you do the forum or yourself no favours by constantly referring to charts beyond t96-120 where we large run to run differences are showing up.

You should know more than most that the Operationals beyond 4-5 days can`t be trusted at the moment.

Leave off the sad pills and let`s have the more objective Steve back please .

Thank you Phil!

[Buzz]

Steve you do the forum or yourself no favours by constantly referring to charts beyond t96-120 where we areseeing large run to run differences..

You should know more than most that the Operationals beyond 4-5 days can`t be trusted at the moment.

Leave off the sad pills and let`s have the more objective Steve back please .

Well said that man - very well put.

[snowmadchrisuk]

Poor ecm,is a midlat high the best we are going to get?

Not liking the trend to relocate the PV across Greenland this evening.

Yeah but look at the huge P/V slab to our East , that could possibly come into play here , A westward correction tomorrow with such low height's to our East is not only possible , Id say likely ....

[Snowman31]

well JMA has some potential I think?

[bobbydog]

can i just ask, at what point do the models factor in data from the SSW (which has only just begun today) and in turn, reflect this in their output?

does anyone actually know and is this even an answerable question?

Edited January 6, 2013 by bobbydog

[mulzy]

Folks - relax, the models will change again especially with so many unsusual background signals - it may get even worse but it could get better but one thing's for sure - it will change again!

Edited January 6, 2013 by mulzy

[IDO]

Well said that man - very well put.

Really, Mr Murr was two frames ahead of the ECM charts all the way through. Including the failure of the UK high to ridge to Greenland, His prose may be emotive but I would suggest you take note as we can all learn a lot from his scripts.

6c uppers above average in the south at T240:

[Grimsby Snow Lover]

Latest tweet from Matt Hugo

I think his last few words are key for further developments over this coming week

Matthew Hugoâ€@MattHugo81

ECM 12z model definitely a downgrade from previous runs but does match some of the previous ensemble members. Masses of uncertainty...

[Jason M]

Ok, so the ECM tonight at 240 looks like its going to take the northerly / Greenland high route just after mid month. Tbh this is in line with what others were predicting.

I'm still far from convinced that the models have nailed the pressure pattern over scandi at day 5 though. Lots of changes to come I suspect as it looks very complex.

Also, people should wait for the ensembles anyway.

Jason

[-uksnow-]

Yeah but look at the huge P/V slab to our East , that could possibly come into play here , A westward correction tomorrow with such low height's to our East is not only possible , Id say likely ....

And I'd say your mad too much energy into Greenland for the second shot at a northerly at 240 to materialise aswell, but you can't call a westwards shift with no evidence!

IMO, I'm not overly phased by today's runs, it was always going to be a highly uncertain time and whilst no models have a great handle on what's coming its best to keep your toys in the pram and listen to the wise words of Exeter and Ian F until we have more certainty, otherwise half of you on here will have had a heart attack by the time cold weather actually arrives..

[snowmadchrisuk]

can i just ask, at what point do the models factor in data from the SSW (which has only just begun today) and in turn, reflect this in their output?

They don't as such , they will factor in the state things are in at +0 , so as the SSW starts to take effect in the strat , the models will pick on it from initial starting conditions .

[Jaffusmaximus]

Is there such a thing as " Model Downgrade Ramping "?

I have not seen a hint of zonal in any runs, so that must be the good thing?

[Crystal Memories]

I very rarely post in here because I refused to get sucked in to all the false ramping or doom mungering but I do follow to try and learn from more experienced users, But there seems to be very little acknowledgement to the fact our whole weather system has dramatically changed over the last 20 years & this is why the computers are finding it nearly impossible to read anything past 48hrs so my point is why do so many people get in to arguments over something that is so inaccurate that you may as well toss a coin as to when or if? cold weather will get here or not.

[The PIT]

RIP icebergs and polar bears. At least this mild rubbish is going to end and we're going to rather cold conditions but nothing remarkable and little chance of widespread snow.

If they stay like this some miserable wet days coming up if the GFS is right. ECM we may get some sunny days and frosty starts.

[snowking]

Well another run, another different solution! Isn't that refreshing

The initial easterly potential has evaporated rather quickly, and it must be said the GFS has done well in the last few months on picking up an idea first, and, where necessary, dropping it first. It's upgrade last year must have helped!

We do see a rather similar idea in the longer term from both the ECMWF and the GFS in terms of an elongated block across the atlantic as the Siberian becoming Scandinavian vortex drops south, but with such differences in the earlier timeframes this is pure guesswork.

But what FI in both ECMWF and GFS should show is there are plenty more opportunities over the next few weeks for something colder given the state of the stratosphere. This is never a guarantee as we are all too familiar with but then again, nothing beyond day 4 is particularly reliable at the moment.

More twists and turns to come yet i'm sure, which will result in more tantrums on here no doubt.

SK

[russell k]

All the NWP's are showing it getting colder in the next 5 days, the MO are saying this with the chance of some wintry weather next weekend, it was always after this the chance of a real cold spell would materialise. Absence of evidence is not evidence of absence! Keep looking for the cold.

[Dexter29]

Steve you do the forum or yourself no favours by constantly referring to charts beyond t96-120 where we areseeing large run to run differences..

You should know more than most that the Operationals beyond 4-5 days can`t be trusted at the moment.

Leave off the sad pills and let`s have the more objective Steve back please .

Eh? Doesn't the same apply to members posting charts out in la la land looking for a second chance/bite at cherry making assumptions that the cold will still arrive.

The evening 6th January and we have no decent cold or snow in the next 7 days, I don't know about anyone else but in my eyes, Steve is calling this spot on!

[weather eater]

We could well see a change to a more colder E,ly flow at this timeframe because +120/144 is always subject to change. When the model output becomes consistent is from +72. This is why many of us say getting an E,ly at +72 is the holy grail.

Yep I've been saying this all winter Stella runs at 120hrs plus are useless, screaming northerly’s, raging Easterlies we have seen them come and go in the 120hr plus time period loads of times in the last few years, that’s why some of us keep saying it’s wise to be cautious. However that does not mean that we are pessimistic of achieving a cold spell this winter, far from it in fact, plenty of changes to come over the next few days and lots of interest.

[Mr Frost]

The Scandinavian high is the skid mark on the underpants of weather forums throughout Europe.

Give me a Greenland high over that solution any day in Winter!

To sum up all charts for today so far...trending seasonal...slight warm up and then colder. It is as easy as that folks!

Edited January 6, 2013 by Mr Frost

[MR EXTREMES]

An essentially cold but dry pattern showing on the ECMWF at around T+120-192- the 850hPa temperatures are generally above -5C and this would not support snow showers off the North Sea, in contrast to this morning's offering, but the ECM was always at odds with the UKMO/GFS on that particular easterly outbreak.

The amount of divergence between the UKMO/ECMWF/GFS is indeed staggering at T+120 onwards and the models are clearly struggling to deal with the impacts of the sudden stratospheric warming event on the weather in the vicinity of the British Isles. Below-average temperatures look a highly likely bet, but it is impossible to call whether or not it will be cold or moist enough for snow.

My long-range forecast issued a few days ago went for a very cold and possibly snowy spell (though with considerable uncertainty attached) in the last third of January and to be honest I've been surprised by how abrupt the shift in synoptic pattern is progged to be at present. It may well be that if we do get a snowy spell, rather than being ushered in initially by an easterly, it might come on the back of a northerly plunge, as the ECMWF has been very consistent recently in projecting a Scandinavian trough and Atlantic/Greenland blocking around mid-January.

and the chart your looking for is this chart northely then ne flow intresting.

[ANYWEATHER]

Just look at the difference betwwen the gfs and ecm at T+168, dry cold/wet cold!! Take your pick!!!Emphasis on a colder trend !