Model Output Discussion

[nick sussex]

To be honest IF we get a Euro High joining up with a High further North 2 people should be congratulated here

Nick Sussex who called it early and GP who has called a late Dec colder spell from day 1....If it comes up Mild as I hope Ill be coating them hehe....Only joking.....They are near the mark and fantastic to see to be honest that they can call this so early

Me ill stick with NOAA for a not so cold scenario and stick with ECM at moment

That's very nice of you CV I think the euro high looks almost certain but it could still go either way after this , we really need that trough to the west to go further west. It's really nerve shredding at the moment if you're a cold and snow lover. And if you read GPs post just now it might be the models but more especially the gfs are too quick, even if the easterly doesn't make it we might still end up with some inversion cold and need a second bite of the cherry, but anyway i'm going to be optimistic here.

Edited December 4, 2009 by nick sussex

[MR EXTREMES]

Amazingly, the potential evolution of a monster cold spell is only a week away and the next few days will be a major test of the models credibility, the ECM 12z T+240 chart has stunning potential and the GFS 12z is simply awesome and would surely give the uk it's most wintry spell for several years, it's good that these stonking charts are not just buried deep in FI as they could be dismissed as nonsense but I just have this horrible feeling that it could all implode by tomorrow or sunday because we have seen huge potential evaporate before many times.

this is my feeling dont get me wrong i luv this,

and i wait with fingers toes everything crossed,

but we coldies might have a breakdown tomorrow so im going for this as a phantom runs lol.

but by god i hope im wrong,

white christmas i never seen one of them in my llife so it would be something very special,

but i just dont trust the models there to erratic and very unrealistic in my opion.

[cyclonic happiness]

That's very nice of you CV I think the euro high looks almost certain but it could still go either way after this , we really need that trough to the west to go further west. It's really nerve shredding at the moment if you're a cold and snow lover.

hehe, you as well as the rest of us, must have seen it so many times in the past going all pear shaped, that i feel we are almost immune to it

[Frosty.]

An excellent read there GP

[NorthantsSnow]

Amazingly, the potential evolution of a monster cold spell is only a week away and the next few days will be a major test of the models credibility, the ECM 12z T+240 chart has stunning potential and the GFS 12z is simply awesome and would surely give the uk it's most wintry spell for several years, it's good that these stonking charts are not just buried deep in FI as they could be dismissed as nonsense but I just have this horrible feeling that it could all implode by tomorrow or sunday because we have seen huge potential evaporate before many times.

It looks to me like the floodgates so to speak are about to open from the NE with a chilly blast to follow as the HP asserts itself in all the right places.

That's just my (admittedly amateur) take on the +240 chart. Some had already commented earlier in the evening that the GFS may be rushing things somewhat but was otherwise showing a plausible pattern, so interesting to see that reflected in the ECM.

Not ideal though when a potential cold spell keeps getting delayed as it extends the model rollercoaster ten-fold. Emotions will be running high enough as it is over the coming days especially if the output continues to be volatile.

[MR EXTREMES]

thankyou gp intresting stuff indeed.

[Frosty.]

this is my feeling dont get me wrong i luv this,

and i wait with fingers toes everything crossed,

but we coldies might have a breakdown tomorrow so im going for this as a phantom runs lol.

but by god i hope im wrong,

white christmas i never seen one of them in my llife so it would be something very special,

but i just dont trust the models there to erratic and very unrealistic in my opion.

All the disappointments of previous cold spell failures will evaporate if this comes off, I think it's very good and positive news when we have the comments from GP added to the mega wintry charts, maybe fantasy will become reality in less than two weeks.

[kold weather]

Well the models are very interesting indeed once again...they are now if anything even more agressive with the idea of building a high pressure far enough orth to allow cold inversions, if the ECM and GFS are correct then we should start to see the results of that, though much depends on the sort of high it is and how cloudy it is.

What GP says to me could be very interesting IF we can get a easterly flow, I wouldn't be all that surprised a slow snowy breakdown.

A more likely situation though IMO is we hold the high just a little to close to the UK, probably would steadily cool down depending on the amount of cloud cover of course. Nic, I think the second bite is whats going to be needed in this one but as GP said I'd veiw this as a building block situation, probably the most realisitic way of shunting us towards a -ve AO, far more so then the runs of a few days ago.

[NorthantsSnow]

this is my feeling dont get me wrong i luv this,

and i wait with fingers toes everything crossed,

but we coldies might have a breakdown tomorrow so im going for this as a phantom runs lol.

but by god i hope im wrong,

white christmas i never seen one of them in my llife so it would be something very special,

but i just dont trust the models there to erratic and very unrealistic in my opion.

I understand what you are saying particularly if you are only taking a single run in isolation, this is why all output must be considered. GFS, ECM, UKMO, minor models, ensemble data + theme of the past few runs. Only when taking all this into account can you get a true feel for the direction in which things are headed. Too many people put all their eggs in one basket so to speak and panic as soon as the latest GFS run doesn't meet their expectations. This is not a healthy approach to the models! (not accusing you of this by the way)

[Glacier Point]

All the disappointments of previous cold spell failures will evaporate if this comes off, I think it's very good and positive news when we have the comments from GP added to the mega wintry charts, maybe fantasy will become reality in less than two weeks.

... might just be a touch progressive Karl, at least for the FIRST westward push that impacts the Uk...

Edited December 4, 2009 by Glacier Point

[Methuselah]

IF we get -15C uppers, it'll be a bit nippy, irrespective of cloud-cover, IMO??

[Frosty.]

... might just be a touch progressive Karl, at least for the westward push that impacts the Uk...

I got a bit carried away I'm very pleased with the overall trend though which could gather momentum..that's what i'm hoping anyway.

[kold weather]

GP, yeah I personally think we won't get into the real cold stuff and our cold stuff will come through the inversions, something rather similar to the 12z ECM IMO. I think the best long term chances for the UK in terms of getting a decent cold spell would be to have the Atlantic trough being a little further to the west then it has been before, that way we could keep a mainly SE type flow into the UK for longer, then hopefully when we get a trigger low and heights rising across the poles we would already been in a pretty cold set-up.

I also agree the GFS is being progressive, but IF things go as well as it could then the 12z GFS should be achievable towards the end of the month...typical of a 80s style winter I suppose!

I have to admit I'm very interesting in seeing the -ve AO, I really think add the storm risk in with a possibly strong -ve AO/NAO and you have a higher then normal risk of a big snow event.

Peter, temps would max below 0C yet alone night time temps, think its fair to say it'd be nippy!

Edited December 4, 2009 by kold weather

[MR EXTREMES]

All the disappointments of previous cold spell failures will evaporate if this comes off, I think it's very good and positive news when we have the comments from GP added to the mega wintry charts, maybe fantasy will become reality in less than two weeks.

sorry little of topic done the 100f bet at the bookies in 2003 and i got it right.

i wanna wait another few days to see if models keep our hopes alive if so 20 quid goes on white christmas,

but the 100f was only 2 quid.

but im watching.

im staying on the warm side i dont care about money,

but if the good runs we have seen tonight are right im gonna be happy 1 flake of snow in london would be fantastic.

but if the uk where to see something special i be even more happy come on winter 09/10 and the models bring it on.

[Methuselah]

Better get your bet in now, BB...Before the Express makes its annual Snowmaggeddon forecast??

[PersianPaladin]

Having seen the latest models I think the chances of a cold easterly or north-easterly incursion around midmonth has increased from 10% to 20-30%.

GFS and ECMWF both agree on high pressure building from the south and high pressure then cutting off the continued stream of depressions and heights building to the north. From there it is still quite a tall order to get the cold air as far west and south as Britain, which is why I am implying 70-80% chance that it won't happen. But we are closer.

For me, F.I is pretty much T120+ onwards in terms of the establishment of an intensifying upper trough and greater amplitude of the tropospheric-vortex in central-NW'strn Canada. The orientation of surface-lows coming out of Newfoundland is going to complicate the picture in terms of the development of heights north of Britain and into East Greenland. Expect things to get very messy before we're getting stable WAA polewards.

[MR EXTREMES]

Better get your bet in now, BB...Before the Express makes its annual Snowmaggeddon forecast??

lol i will if the models play ball just a couple more days and i be there be like winning the lottery sod the money the pics and the happy people would be enough for me lol.

i hate winter but i luv it to lol.

[cooling climate]

GP could well be right but I would not be surprised to see very cold weather impacting Europe and

the UK from the 15th, 16th onwards then getting progressively colder.

If the operational ECM is correct then four or five days later than this.

[bluearmy]

ok - i'll be the fall guy and say the angle of WAA not quite as good on 18z as 12z and looking like some energy ejecting ne from the trough. more like ecm12z in that respect but not as progressive.

[Methuselah]

lol i will if the models play ball just a couple more days and i be there be like winning the lottery sod the money the pics and the happy people would be enough for me lol.

i hate winter but i luv it to lol.

Me too... But, don't wait too long - or the odds'll be less than even???

You know how the Press thinks!

[snowmadchrisuk]

18z is Not looking as good as 12z and seems to be going towards Ecm with that 1000 mb low above our high. Although it does start to fill at +162 .

Edited December 4, 2009 by snowmadchrisuk

[MR EXTREMES]

Me too... But, don't wait too long - or the odds'll be less than even???

You know how the Press thinks!

express headlines:

we have just looked at the gfs get your bets on BIG FREEZE IS COMING PACK YA BAGS AND MOVE SOUTH LOL.

[I remember Atlantic 252]

I think the eventual outcome will be similar to the dec 2002 easterly, not a beast but a cold easterly had a few snow flurries on 12th

[snowmadchrisuk]

I think the eventual outcome will be similar to the dec 2002 easterly, not a beast but a cold easterly had a few snow flurries on 12th

Well according to 18z were there by the 12th (Next Sat) with -5 across the country. Every run that goes by seems to be bringing it forwards. I hope it isn't going to be a case of 1 step forwards 2 steps back .

[LomondSnowstorm]

Overall, not really as good as the other runs, but as the easterly is still in FI you can't really expect total consistency, even if it were to come off.

Edited December 4, 2009 by LomondSnowstorm