General Model Output Discussion

[Optimus Prime]

I don't like delving into 'FI' or whatever they call it territory but I am right in thinking at the Greenland high is on it's way out in about 168 hours time?

That potentially leads to a whole new set of cold scenarios.

[kold weather]

Yep that looks possibloe now OP, good agreement on that happening. The models also suggesting high pressure develops near the UK though of course the exacts are quite uncertain but the broad trend is cropping up on nearly every run now between the 8-12th...regardless of eventual outcomes I'd have thought a cold HP spell looks quite possible, after that and it wil lbe interesting to see what happens it has to be said, I wouldn't be in the least bit surprised to see the upper high near the UK lift back northwards at least to some degree...but that really is far too far away to make a call yet!

[we_want_snow]

I don't like delving into 'FI' or whatever they call it territory but I am right in thinking at the Greenland high is on it's way out in about 168 hours time?

That potentially leads to a whole new set of cold scenarios.

What does that lead to?

[Paul]

Latest video forecast from Michael Fish now online:

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

[Optimus Prime]

I wouldn't be in the least bit surprised to see the upper high near the UK lift back northwards at least to some degree...but that really is far too far away to make a call yet!

That's exactly what I was thinking. A rather brief inversion/cold easterly for the south followed by retrogression to Greenland. But perhaps more historically Scandinavia where it'd be better suited for us.

I guess it all depends on the Polar Vortex giving the go ahead on this one. And whether the Jet blasts through us which looking out into deal or no deal land is quite unlikely.

[nick sussex]

Some posters on here are even more fickle than the crowd which allegedly welcomed Jesus with palm fronds one Sunday, only to crucify him five days later. It really is absolutely ridiculous to have to trawl through the whining whingeing drivel on here day after day that has little or nothing to do with model outputs. Sorry but this has to be said.

The synoptics are probably the best we've seen in this country since the 1980's. It is December 31st, not March 31st and the two pricipal winter months lie in front of us, off a very cold start. Now for goodness sake: grow up some of you.

Unfortunately WIB some people look at things from a glass half empty perspective. Some members obviously have forgotten many of the recent winters when a two day cold spell was as good as it got! The synoptics generally for the last two weeks have lead many to believe that this cold lark is easy so then immediately start getting hysterical if the snow isn't two feet deep by the next morning!

I think you'll find most of the regulars have been quite relaxed about things, most of the whining has come from the snow groupies as i like to call them, turn up at the first whiff of snow and then proceed to throw toys out of prams when eskimos aren't holding a winter jamboree on their front lawn!

People need to realize that the synoptics of the last few weeks and going forward probably for quite some time are extremely rare especially in recent winters, how much snow that translates to is still up in the air, however it would be nice if people just cut the moaning out in here and save it for the whining thread.

There have been times when it's been like hitting your head against a brick wall! of course i do understand that people want to see some snow and it can get a little frustrating but it's even more frustrating when we've sat here for weeks on end just trying to find a frost in the model output!

Edited December 31, 2009 by nick sussex

[West is Best]

I think you'll find most of the regulars have been quite relaxed about things, most of the whining has come from the snow groupies as i like to call them, turn up at the first whiff of snow and then proceed to throw toys out of prams when eskimos aren't holding a winter jamboree on their front lawn!

Spot on post Nick - every word.

The 12z's start to roll soon. Once again the key thing is that the patterns remain conducive to medium-term, or even long-term, cold. Snowfall is something that tends to occur out of the right setups.

p.s. I hear they've just cancelled Edinburgh Hogmany celebrations due to heavy snow (at least I think that's what Sky just said? Don't quote me on that if you're going.)

Edited December 31, 2009 by West is Best

[johnholmes]

re the two posts from WIB and Nick Sussex

Please try and take note at what they have said-take a relaxed look at the weather-it is no different to the supposed deep cold winters.

They were cold-some of us got snow some did not-that is the way of the world-

By the law of averages IF the cold persists then its probably a fair bet that about 95% of the country will have seen snow on the ground at some point. The 5% that have not then if you are in that 5% its probable that you rarely see snow anyway.

As someone who has passed 70 and was told a couple of winters ago that I had 'enjoyed' every one bar two I think of the severe winters in the 20th century-these charts are quite unusual-enjoy them-my December stats show that this month is the 13th coldest in this area in almost 70 years-not as snowy as some but still a decent amount for this fairly snowless part of the world.

enjoy the models-its almost the New Year-how about a NY resolution and one to TRY and KEEP.

Be kind and considerate to one another-we are all human and sometimes we will get up one another's' noses. All on here are weather fanatics-most are, in winter, cold lovers-so enjoy-be grateful if your garden fills with the white stuff at some time this winter and be genuinely sorry for those whose garden stays a browny-green, apart from the frost.

Its going to be a cold or very cold 10-14 days-snow WILL fall for many-trust me-not everywhere at the same time though.

My NY resolution to stop telling those of you off who never take any notice anyway and boring the pants of the majority who behave sensibly.

sorry mods I promise!!

Edited December 31, 2009 by johnholmes

[londonsnow]

couldn't agree more with nick sussex. complacency is dangerous. we have waited a long while for such synoptics. it may not deliver to everyone, but be glad that it's still possible!

[weather eater]

People need to realize that the synoptics of the last few weeks and going forward probably for quite some time are extremely rare especially in recent winters, how much snow that translates to is still up in the air, however it would be nice if people just cut the moaning out in here and save it for the whining thread.

Blimey that made me laugh, I suppose we have to remember that we live in an age of instant gratification, football managers are throw out before they have a chance to get things right, the music Biz is no longer about pursuing your art form but about fame, do some karaoke become famous, never mind plugging round the circuit for a few years, honing your skills.

Back to the models its looking increasingly likely that the high will sink, high model uncertainty on how that will work out for us, which is why I think predictions of a very cold January need to be treated with a degree of caution. But for the moment lets enjoy what we've got, that further evolution is going to do a fair amount of chopping and changing before we know where we are going during January week 2, never mind the rest of the month.

[bluearmy]

I don't like delving into 'FI' or whatever they call it territory but I am right in thinking at the Greenland high is on it's way out in about 168 hours time?

That potentially leads to a whole new set of cold scenarios.

it went a week ago aswell - but returned when none of the models foretold it would at more than T192/T216. i would 'bin it' at your peril, though we may see the centre of blocking propensity move eastwards.

[kold weather]

That's exactly what I was thinking. A rather brief inversion/cold easterly for the south followed by retrogression to Greenland. But perhaps more historically Scandinavia where it'd be better suited for us.

I guess it all depends on the Polar Vortex giving the go ahead on this one. And whether the Jet blasts through us which looking out into deal or no deal land is quite unlikely.

The interesting and somewhat unusual thing about this set-up is the way the Greenland decays is by the PV itself shifting back towards Greenland which shunts the upper high S/SE, it keeps its shape and strength and the jet stays in a similar position at least for a little while, so if the PV does shift again then the upper high will very likely once again be propped back up, as you say the exacts depends on where the PV ends up, over Canada and we will probably end up in a very long and probably very cold SE/ESE airflow, if it shifts towards Scandinavia then the high will at first sink further then eventually build back NW the next time a shortwave swings up the western side of the block...the only weay out of this cold spell before day 10 us for the PV to come so far south the high ends up shifting into either Europe or becomes a displaced Azores high, neither are at all likely though.

[nick sussex]

Spot on post Nick - every word.

The 12z's start to roll soon. Once again the key thing is that the patterns remain conducive to medium-term, or even long-term, cold. Snowfall is something that tends to occur out of the right setups.

p.s. I hear they've just cancelled Edinburgh Hogmany celebrations due to heavy snow (at least I think that's what Sky just said? Don't quote me on that if you're going.)

Thanks WIB

I'm shocked if they have cancelled the celebratons, what more perfect a scene can you have than snow falling and welcoming the New Year in, let me guess it was done on safety grounds in case someone slips on an icy pavement and then sues the council! what a shame if they have cancelled them i mean what a shock snow falling in winter! didn't they think of this beforehand! Anyway back to the model output, well i'm going for sw low joining up with Scandi trough, several days of ne winds greenie high edging east centring nw to north of Scotland, another hit of even colder upper air heading west on the southern flank of the high more likely for southern and se areas, after that who knows!

I suppose you're most interested currently in the possible Channel low for early next week, difficult call that but good luck hope you see some snow.

Edited December 31, 2009 by nick sussex

[NorthantsSnow]

Back to the models its looking increasingly likely that the high will sink, high model uncertainty on how that will work out for us, which is why I think predictions of a very cold January need to be treated with a degree of caution. But for the moment lets enjoy what we've got, that further evolution is going to do a fair amount of chopping and changing before we know where we are going during January week 2, never mind the rest of the month.

I wholeheartedly agree. By T180 most bar about 1 of the ensembles have sunk the high:

http://209.197.11.108/c9s4a5k3/cds/ensimages/ens.20091231/06/slp-180.png?dopvhost=charts.netweather.tv&doppl=0f36092b440ac81d445ac84d959fc312445ac892&dopsig=e506654be4b6dfc1f187957e914c4d1d

Best case scenario is probably something like P17 where the high splits and some returns to the Iceland area, keeping us in a bitterly cold easterly flow.

Worst case scenario would likely be P15 with the high sinking over us and adopting something of a Bartlett style position.

[Big Innes Madori]

Thanks WIB

I'm shocked if they have cancelled the celebratons, what more perfect a scene can you have than snow falling and welcoming the New Year in, let me guess it was done on safety grounds in case someone slips on an icy pavement and then sues the council! what a shame if they have cancelled them i mean what a shock snow falling in winter! didn't they think of this beforehand! Anyway back to the model output, well i'm going for sw low joining up with Scandi trough, several days of ne winds greenie high edging east centring nw to north of Scotland, another hit of even colder upper air heading west on the southern flank of the high more likely for southern and se areas, after that who knows!

I suppose you're most interested currently in the possible Channel low for early next week, difficult call that but good luck hope you see some snow.

Guys,

I think that its Inverness that has been cancelled?

Sorry for being off topic mods

Big Innes

Edited December 31, 2009 by Big Innes Madori

[Optimus Prime]

Worst case scenario would likely be P15 with the high sinking over us and adopting something of a Bartlett style position.

But with the Jet that far south does a 'Bartlett' scenario really have any support at all?

[SMU]

Dont worry folks I will be here to liven the place up with some excitable posts later!!!!

T12 GFS V T18 6z & the isolines & surface flow are slightly more condusive for PPN moving a little more inland- winds are slightly more ENE rather than NE-

Still very good for suffolk, kent ( N&E) & EA...In terms of the 12z- each 12z has corrected the GH further North against the 6z,the same as the 00z V the 18z-

Taking all things into condieration I am happy that the evolution of GH toppling slightly to Scandi surface high is very really realistic- if this were to happen the chances of sustained & heavy snow rise, especially more widely in the SE & ALong the south coast- & possibly further north depending on how far th Easterly winds filter up the coast-

lets se how it develops-

Steve

[nick sussex]

But with the Jet that far south does a 'Bartlett' scenario really have any support at all?

No chance of a bartlett high with the jet south, IMO the worse case scenario would be a high sitting over the uk but that could still keep things cold, i feel its going to be a high to the north with still an easterly flow for southern areas, after this with the PV still disorganised a chance for another reload back to more wintry conditions.

[NorthantsSnow]

But with the Jet that far south does a 'Bartlett' scenario really have any support at all?

That's a point. Certainly it's pretty shortlived on that particular perturbation where an absolute massive LOW appears from nowhere in the Atlantic and squeezes the high out.

But I'm not for one minute saying a Bartlett is at all likely, just trying to illustrate that perhaps sustained cold is not yet nailed.

Edited December 31, 2009 by NorthantsSnow

[weather eater]

But with the Jet that far south does a 'Bartlett' scenario really have any support at all?

I don't see a Bartlett, we could however have the high sink over us and stick, while that might lead to some very cold minima's it would also unleash a fresh barrage from the I want snow and I want it now posse. I don't think we will know for sure for a few days, so I see no point in ramping up mega cold month predictions just yet. Sometimes I wish we were still in the world of forecasts only going out a few days, if that were the case I'm sure we would get the excitement of current conditions, the expectation of not knowing what's round the corner and none of the downers caused by model runs that promise but never seem to be able to deliver.

[Iceberg]

The 12Z is back to taking an more organised band of light precip down the country Saturday night as it makes more of the small low pressure trough/front.

Edited December 31, 2009 by Iceberg

[nick sussex]

The fact that the gfs 12hrs is making less of an issue of the Channel low suggests to me that the others are now very unlikely to take this any further north, this run would always be the one most likely to overblow the low, the fact it doesn't makes a southwards projection by the others more likely.

[Upgrade]

The fact that the gfs 12hrs is making less of an issue of the Channel low suggests to me that the others are now very unlikely to take this any further north, this run would always be the one most likely to overblow the low, the fact it doesn't makes a southwards projection by the others more likely.

So that means the chance for further deep cold and a stronger north easterly blast increases, i would expect.

[SMU]

The 12Z is back to taking an more organised band of light precip down the country Saturday night as it makes more of the small low pressure trough/front.

http://91.121.94.83/modeles/gfs/run/gfsnh-0-66.png?12

http://91.121.94.83/modeles/gfs/run/gfsnh-0-72.png?12

THis is quite an epic chart & looks the 'cleanest'so far-

I think the PPN is off along the south coast this time, however the surface flow & low heights & sub -10 uppers will generate sufficent convection for the Eastern & south Eastern peripheries-

Key timeframe is 120-180 for the UK in terms of Easterly flow then the possible Scandi High-

S

[nick sussex]

So that means the chance for further deep cold and a stronger north easterly blast increases, i would expect.

Well the orientation of the Greenland high looks even more favourable on this gfs run. However of course there will be some disappointment by sw members if the others keep the low further south aswell.

Edited December 31, 2009 by nick sussex