Winter Model Discussion - The Hunt For Cold - 12th Dec

[stainesbloke]

Could someone explain why when the models were predicting an icy/snowy Christmas and more or less changed overnight to the opposite a week ago, why people are talking about no more cold until mid January which is over a month away?

Surely the models could do a somersault next week and winter's back on track Christmas new year onwards. I don't understand why people take the models so seriously — is there some physical caste iron reason why the next month is going to be dire or is it just the models which say so?

No, there isn't a caste iron reason why January is going to be dire....its all guesswork, no chart goes past New Year atm. The models are saying milder for the next week with Atlantic dominated weather but after that they don't all point the same way. If the charts can flip so massively like they did last week they can do it again. I'm not saying they will, just that they can....and with most of winter still to come nothing is certain.

[Methuselah]

There is always Nibiru and 21/12/12.......about the same chance as massive blocking from east linking to Greenland bringing a prolonged freeze to our shores...lol. Never mind, Christmas is coming

BFTP

Pity there's no BFTE until after the 22nd!

[Geordiesnow]

Certainly some coolish Atlantic spell of weather coming up - no real disaster as there is still enough time for snow events to come along and on a personal POV, its can give a little breather of chasing up promise that never really came off.

Although quite a bit rainfall is projected, the good news in my eyes it does not look like we will see much in the way of stalling weather systems so the weather on the whole should be sunny for the most part with the exception of west facing coast which should experience some potentially interesting convective weather with cool uppers and fairly low thicknesses!

[BLAST FROM THE PAST]

Do you simply mean the LP or is that a big hint? If a massive LP is in the Atlantic can it draw much colder air from the north not usually associated with normal LPs? Limited knowledge, sorry if a stupid question.

No it is just one HUGE LP that covers a few thousand miles and clearly very unusual. Its Probably why it looks like taking charge. Its position means the air will come from a southern quadrant, initially SE then veering SW'ly.

BFTP

[SouthPennine88]

Yes nick I couldn't agree more, time to put this horrible episode behind us and move on, the models show mediocre fayre for the next 2 weeks plus and now i'm concerned about longer range prospects into the new year and beyond, time to wipe the slate clean and start again I think.

As I did say, there's no reason to worry about the new year and beyond just yet because that is over a month away and the models only go out to two weeks.

Without a doubt we will see a change in the output within that period.

A day of mild outputs and you'd thing Spring arrives on Friday, and not day 14 of the Winter

[SilverWolf]

With any LP in the Atlantic we need it to cross us, or better still undercut us as the cold air will always be drawn down the western flank. If its in the Atlantic it can be any size it wants, it's of no use to us for cold as we're stuck on the east of it.

Thank you. Was BFTP hinting it was coming our way and would bring much colder weather from the NW as it travelled over us, perhaps contrary to model outputs or the fact that many are looking east for our source of cold?

Edit just seen your post BFTP thanks

Edited December 12, 2012 by SilverWolf

[BLAST FROM THE PAST]

Pity there's no BFTE until after the 22nd!

Nice to have some humour in this Pete , very close to seeing something great so early wasn't it......and that is the point folk must take from this....IT IS SO EARLY in winter...let's chill and enjoy what models next throw at us

BFTP

[karlos1983]

Yes nick I couldn't agree more, time to put this horrible episode behind us and move on, the models show mediocre fayre for the next 2 weeks plus and now i'm concerned about longer range prospects into the new year and beyond, time to wipe the slate clean and start again I think.

Lol! yes my full review will be out after the ECM ensembles, expect lots of silly analogies, desperate stabs at humour, at least we don't have to talk about the Russian high, flattered to deceive once again and good riddance to it, if theres one thing I hate its that false hope giver!!!

And yes my optimism rating will be out, probably together with a few additions.

I'm fairly new to this lark, only been watching models for 3 winters now and I can happily say that in future, I will not be confident of any beast from the east arriving until its +24 from verifying, even then ill be nervous! The most frustrating, teasing, emotionally challenging period of model watching I have endured!

A bit like Arsenal being guaranteed the carling cup, never really going to happen is it!

[cerneman]

Ian Ferguson mentions that Met office experimental long range winter forecast shows Zonal winter,,,,,,Thats it folks all over, Lets hope it shows Barbecue summer?

[Carl46Wrexham]

I think there is a lot of pessimism around at the moment because the models seem to indicate a flat zonal pattern all the way....

As we all know from bitter (for want of a better word) experience, once a zonal pattern gets its feet under the table, it can have a nasty tendency to stay in place for weeks and weeks, trashing a large chunk of the winter in the process. God forbid, I hope this doesn't happen....after a summer that was worse than useless, a winter that continues the autumnal style theme doesn't bear thinking about!

[nick sussex]

I'm fairly new to this lark, only been watching models for 3 winters now and I can happily say that in future, I will not be confident of any beast from the east arriving until its +24 from verifying, even then ill be nervous! The most frustrating, teasing, emotionally challenging period of model watching I have endured!

A bit like Arsenal being guaranteed the carling cup, never really going to happen is it!

Chasing easterlies does need to come with a health warning!

However that one looked okay after we got over the first shortwave, unfortunately then another one popped up and another one in the USA didn't run ne but east flattening the upstream pattern just when we needed a more sharpened trough to the west.

One of those just happening we may still have seen a better cold spell, both was terminal!

The Russian high we've seen for the last few days to the east was always likely to stay just there, we never saw any strong signals to retrogress the pattern.

Large highs are really not the best to get easterlies, you're much better off with a smallish high over Scandi with trough dropped into Russia.

Those certainly have a better chance of verifying than some huge Siberian high.

[Paul]

For those hoping for some snow, it's already snowing on the christmas skin which is now available to use:

(Please don't comment on this in here or we'll be miles off topic)

[Catacol]

OK. Looking at large scale hemispheric patterns a few comments in this "limbo"phase:

1. The vortex has just begun its shift over to Siberia today. This is the point at which much is uncertain. The residual energy left behind which is forecasted to make a mess of our previous belief in an impending easterly is on its way with the system set to deepen in the next 24 hours.

2. This is the crucial phase, and the point at which uncertainty I still think is very great. I suspect Stewart is quiet for the same reason: there is not much point commenting on the next phase until we see just how this vortex transfer is going to pan out in reality. The previous hunch was that the pattern was going to hold with pressure backing west; with this now much less certain (and the models have totally dropped the idea) I still think we need to see just where this tail of energy goes, how far it undercuts or how fast and far it is deflected back west.

Until this is played out then we are still in no man's land I think.

Looking beyond this though at present the signs are not great. GFS 14 day outlook shows an almost total destruction of the northern blocking signature and height rises over Europe

Let's hope that GFS today has the wrong end of the stick, and that the vortex shift creates as many issues in the next week as it did for the easterly forecast last week!

Edited December 12, 2012 by Catacol_Highlander

[Snowmad79]

As I did say, there's no reason to worry about the new year and beyond just yet because that is over a month away and the models only go out to two weeks.

Without a doubt we will see a change in the output within that period.

A day of mild outputs and you'd thing Spring arrives on Friday, and not day 14 of the Winter

And if output carries on as is then its quite possible some will wake up Xmas day to spring like weather or at least temperatures anyway.

[Zenarcher]

Some very wet and windy weather on they way from Friday to Sunday,

Friday gales across the UK touching over 40mph on the coasts through the morning and afternoon,

Also widespread rainfall across all of the UK throughout Firday,

Very strong winds for Shetland on Saturday morning average speeds around 55mph,

Rain not too much of a problem but still stays around in Western and Northern parts,

Sunday still rain around the same areas on Saturday,

Models after this do show the Atlantic bring in low pressure systems so a unsettled theme may continue into next week. Only thing I can find positive is in the strat thread talk about a possible warming maybe showing towards the end of the month.

Edited December 12, 2012 by weathermaster

[IanR]

with all the doom and gloom among cold lovers after a tease, surely the models can change again on a whim and scupper the mild outlook .

[SouthPennine88]

And if output carries on as is then its quite possible some will wake up Xmas day to spring like weather or at least temperatures anyway.

Well it doesn't matter about the 25th does it :

If we accept we won't get snow on that day or week or half of the month ... then we'll be alright.

[PubliusEnigma]

Could someone explain why when the models were predicting an icy/snowy Christmas and more or less changed overnight to the opposite a week ago, why people are talking about no more cold until mid January which is over a month away?

Surely the models could do a somersault next week and winter's back on track Christmas new year onwards. I don't understand why people take the models so seriously — is there some physical caste iron reason why the next month is going to be dire or is it just the models which say so?

In an honest sentence or two. Firstly An Icy snowy Christmas hasn't been on the cards. The models however did point to a colder than average spell of weather. A while back they originally didn't forecast it to break down to mild so quickly. However they have been showing a change to milder weather for some time now. The reason for an extended outlook into the new year, is that is how the models including the ensembles currently show. Our default weather in this part of the world is rainy damp and mild. So it doesn't take a special set up for it to occur, in the absence of any 'special' circumstances, thats what the weather defaults to. In much the same was as some continental interior in winter, will default to cold frosty and clear, in the absence of any disturbance

of warmer origin passing through. The fact that our default is relativity mild, an both the ECM, and GFS show atlantic dominated weather, there is little at present to suggest a sudden change to cold in two weeks time, in time for Christmas. Hope the above explains some of your questions.

[Luke Best]

No, there isn't a caste iron reason why January is going to be dire....its all guesswork, no chart goes past New Year atm. The models are saying milder for the next week with Atlantic dominated weather but after that they don't all point the same way. If the charts can flip so massively like they did last week they can do it again. I'm not saying they will, just that they can....and with most of winter still to come nothing is certain.

I remember a couple of years ago there was cross-model agreement for zonal when quite suddenly a bitterly cold North-Easterly set in and blew for at least a week bringing copious snow showers with it. I've tried to dig out the charts but cannot find the event - if anyone can post these it would make really interesting viewing, especially with the current scenario in mind.

[Snowmad79]

Well it doesn't matter about the 25th does it :

If we accept we won't get snow on that day or week or half of the month ... then we'll be alright.

Indeed, that's why I'm coming round to the idea of waiting until mid Jan to early Feb for the next bout of wintery weather

[Ice Cube]

I have read a number of post's saying that once the models start to show 'zonal' way out into FI that they are likely to be correct because they model zonal 'better'. I am not convinced by this for the reason that most of the weather we experiance is derived from the jet and hence 'zonal', therefore the model accuracy for GFS, ECM etc at long range would be excellent. We know this not to be the case and so to me they have as much chance of being wrong when they show any pattern. The pictorial view of the results of the various algorithms are IMO only part of the story. The clever bit is when to trust what you 'see' and when you should apply experiance and instinct. It's a bit like a good 'doctor'!

[bradymk]

Has anyone got the link to the ECM postage stamps? Thanks

[Matty M]

The only crumb of comfort this evening is the ECM EPS shows signs of cooling down as we progress from Day 10.

[The Northern Ramper]

Ian Ferguson mentions that Met office experimental long range winter forecast shows Zonal winter,,,,,,Thats it folks all over, Lets hope it shows Barbecue summer?

Like it did two years ago? Leading to them cancelling their seasonal forecast.

[PubliusEnigma]

Ian Ferguson mentions that Met office experimental long range winter forecast shows Zonal winter,,,,,,Thats it folks all over, Lets hope it shows Barbecue summer?

WE are overdue a zonal winter, who knows it might lead to damp dull and cool spring, and break the cycle of dreadful summers. Once

we revert to a more mobile westerly / south westerly as the GFS is hinting at, it is IMO easier to see a pattern change down the line. We just have to work

through the process and hope that with time the PV can head into Scandinavia and the Greeny High can build.