General Model Output Discussion

[Paul T]

Any GFS Run that gives Plymouth the chance of heavy snowfall within T86 is a rarity; keep an eye on that low developing in the channel on wed midnight, it turns around a slaps the south coast (SW) right in the chops.

The FI reload should be taken with a crack of sea salt at the moment, it was a South westerly within this FI timeframe on the previous run, so not even a trend being established to warrant genuine interest.

Out to T126 has so much poitential, its actually unreal.

I was with a mate today, and he said ''so, its gonna be cold is it? how cold?'....it then dawned on me that this spell will probably be the coldest/snowiest in my lifetime so far - and im 26!

Paul

[Spurry]

Obviously any reload -NAO is pure FI, but it has to be a possibility. A couple of people have asked me when its going to get milder and I think have been expecting me to say in a few days time because of the transient nature of our cold spells. 'you're joking' was the response when I said at least a week of cold weather is ahead.

I think it looks like at least a week is pretty much nailed on now, i can't help but be amazed how just when one 'cold' system looks as if it's passing thru' another one lines up to take it's place, i can't ever remember seeing charts thats promise so much for so long

[Geordiesnow]

Model runs are increasingly trying to bring the Scandi high into play which could prolong our easterly set up especially for northern areas where it was looking like a 48-60 hour blast on some of yesterday's runs.

I still think a 48-72 hour easterly set up is likely, we still got to be careful that we don't get carried away and forget the high could still topple over us(which in truthness it won't be a bad thing as it will still be very cold!)

We been waiting for runs like these for a long time and hopefully we can make the most of them!!!

[Yozzer]

Some oranges appearing in the Scandi high too, showing the strength of the block. The GFS is oft criticised for going into default mode in FI (although I'm not sure if that's a strength or a weakness), but on this run it takes it almost to the end of the run before it can manage that. Remarkable agreement at last between the models, giving a high degree of confidence until possibly up to 10 days out. Thereafter who knows, but with 53cm of level snow here at the moment, even if there's not another flake (which there certainly will be) this is just stunning...

[kold weather]

Obviously any reload -NAO is pure FI, but it has to be a possibility. A couple of people have asked me when its going to get milder and I think have been expecting me to say in a few days time because of the transient nature of our cold spells. 'you're joking' was the response when I said at least a week of cold weather is ahead.

Well the reload of the -ve NAO looks very likely, in truth it doesn't really go away, we do see it weaken back towards neutral for a time as the Scandi high develops BUT the upper block develops yet again to our north and that edges back towards Greenland. IMO the broad upper set-up is the most plauseable on the 12z GFS and the 0z ECM also broadly goes for a similar pattern...

The big differences obviously come from the pressure patterns and there is no certainty that any -ve reload will bring in a new NE blast, could just end up seeing a cold ENE/E flow remaining in place and slowly becoming less severe in terms of how cold it is. I wouldn't like to call it.

Obviously any major reload of the -ve NAO will take us upto the 15th with regards to the cold.

[Wayneywoo]

Hasn't the 12z run been the most reliable and consistent

[80sWeather]

The GFS 12z is a dream,may just may come true.Day after day of -10 uppers being dragged across a warm sea,lots of snow showers for everybody ,a very rare chart indeed.

[Harsh Climate]

I dont know about anyone else but I havent seen a bad run within 180h for over a week now!

The gfs 12z would spell armageddon for yorkshire/linconshire/east midlands/south east

[DAVID SNOW]

Hasn't the 12z run been the most reliable and consistent

Just my opinion regarding most consistant runs wrt GFS.

00 best, then the 12, then the 06, and then the 18 pub run.

[MR EXTREMES]

thing is 12z is one run 1 model and although simply lovely charts it is still weather and this as we all know is unrealiable.

im very excited about thease charts but also very skeptical i cant see a reload happening like i said its one run,

i think if you starting getting excited about weather in 7 or more days time and thease outputs as gospel then your ygoing to be dissapointed even so great weather to come next week beyond that im skeptical.

[phil nw.]

GFS shows the -10c uppers moving in Sat bringing nationwide colder uppers.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/27/h850t850eu.png

Possible first extensive iceday south of the border on Sunday.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/27/ukmaxtemp.png.

The North Easterly sets in and over the following next few days re-enforcing cold uppers.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/96/h850t850eu.png

as bands of snow move south west in the unstable flow.

All this by T96hrs and then we have the probable Scandi High to follow,

http://charts.netweather.tv/gfsimages/gfs.20100102/12/144/h850t850eu.png

Still bitingly cold by T144hrs.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/144/ukmaxtemp.png

Classic.

[Harsh Climate]

thing is 12z is one run 1 model and although simply lovely charts it is still weather and this as we all know is unrealiable.

im very excited about thease charts but also very skeptical i cant see a reload happening like i said its one run,

i think if you starting getting excited about weather in 7 or more days time and thease outputs as gospel then your ygoing to be dissapointed even so great weather to come next week beyond that im skeptical.

Yes I agree, this http://charts.netwea.../h850t850eu.png could quite easily turn into milder air piling in from south eastern europe....

The 12z gfs is just one option but certainly shouldnt be dismissed, with the way things are goin at the moment and the current telleconections..

Edited January 2, 2010 by Jed Bickerdike

[swilliam]

Quite cold predicted by the GFS in the highlands for Friday morning

[kold weather]

The thing is Badboy synoptically a reload is the most probable set-up IMO, as I said before that doesn't mean we get a monster NE or anything like that but I'd guess another -ve NAO around the 11-13th is quite possible...

Wil lbe interesting but if this breaksdown before the 15th I'd be surprised given the increasing confidence of another block develop at upper levels near Iceland...hopefully!

BTW, remember what the models did with this cold spell, it was constantly upgraded from a weak Mid-Atlantic high, to a full blown upper Greenland high, also remember the Scandi high idea was orginally a Euro high...notice how the models have under done these features constantly...that should give an idea for a trend, and I'm seeing that trend yet again on the models for the 13-17th period.

[Duncan McAlister]

thing is 12z is one run 1 model and although simply lovely charts it is still weather and this as we all know is unrealiable.

im very excited about thease charts but also very skeptical i cant see a reload happening like i said its one run,

i think if you starting getting excited about weather in 7 or more days time and thease outputs as gospel then your ygoing to be dissapointed even so great weather to come next week beyond that im skeptical.

The ECM 00z doesn't look too bad either

[snowmadchrisuk]

Very impressed with the 12s , with low pressure sitting in the North sea and them biting Easterly winds we will be looking at showers moving inlandnearly everyday from Tuesday till at least Saturday,

[West is Best]

Well that's another sensational 12z GFS in the bag! Amazing synoptics.

And for those who seem intent on drawing our attention to 7 days'+ away ... fair bit of snow around already today, and over the next few days. There really is no need to 'strain to see fern seed a mile away, when there's an elephant in front of you'*. This is a cold setup right from the present, which is why a lot of us are surprisingly relaxed and happy about things!

Enjoy: stunning cold weather.

*C.S.Lewis: 'Fern Seed & Elephants'

Edited January 2, 2010 by West is Best

[phil nw.]

No nasty suprises from UKMO,steady as she goes,

http://www.wetterzentrale.de/pics/Rukm961.gif

http://www.wetterzentrale.de/pics/Rukm1201.gif

http://www.wetterzentrale.de/pics/Rukm1441.gif

Same pattern with the Scandi high at the end.

[Polar Continental]

GFS shows the -10c uppers moving in Sat bringing nationwide colder uppers.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/27/h850t850eu.png

Possible first extensive iceday south of the border on Sunday.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/27/ukmaxtemp.png.

The North Easterly sets in and over the following next few days re-enforcing cold uppers.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/96/h850t850eu.png

as bands of snow move south west in the unstable flow.

All this by T96hrs and then we have the probable Scandi High to follow,

http://charts.netweather.tv/gfsimages/gfs.20100102/12/144/h850t850eu.png

Still bitingly cold by T144hrs.

http://charts.netweather.tv/gfsimages/gfs.20100102/12/144/ukmaxtemp.png

Classic.

Hi Phil,

It is indeed classic stuff, the charts currently being shown are probably something like we would have been looking at during 62-63 78-79, if Internet technology had existed back then.

If the models verify and the intense cold continues to the end of January, we could well be looking at a negative mean temperature for the first time since February 1986.

Edited January 2, 2010 by Polar Continental

[Frosty.]

I think northern and eastern scotland will need a breather after the wintry mayhem between sunday night and thursday morning, as for the south & east of england, the gfs 12z is showing white-out conditions, I think snow depths from this spell could be extreme and drifting will be an additional hazard together with severe penetrating frosts. The reload is a surprise, I wasn't expecting another blast from the northeast as the gfs shows but it's just an idea at the moment, the main thing is we will remain locked in a bitterly cold spell until at least mid month on this evidence.

[Methuselah]

Quite cold predicted by the GFS in the highlands for Friday morning

Aye. And, it's starting to worry me...Apart from the far-reaches of FI, there's no sign of any respite, either...

[BLAST FROM THE PAST]

With such cold entrenched across a wide swathe of NW Europe and Scandinavia this cold will remain in place for sometime....minimum 12 days from today possibly longer. I mentioned that in such a set up that the easterlies progged yesterday and slightly lessened overnight may indeed upgrade. I indeed favour what the 12z shows as regards to the quicker surge of deep ENE'lies and then a reloading pattern. I think this spell ahead is going to be in the 'harsh' category so look after the vulnerable around you....it will get brilliant yet nasty.

BFTP

[kold weather]

Yep BFTP I also think the 12z GFS isn't going to be far wrong though I think it maybe a touch fast past the 12th with how it evolves the pattern.

Ensembles look pretty amazing, still a split with what happens after the 13th but importantly still very good agreement on the cold pool being in place...and remember what I said yesterday, as long as the cold pool is in place then the weather is going to be bitterly cold regardless of the exact wind direction. For once we haven;t got to advect the cold from somewhere, because its already here!

Frankly the best ensembles I've seen given how they start cold and many end still bitterly cold.

[morfius]

Does anyone have any idea when the uppers over North Africa last dropped to -5c and below? Surely this would bring snow showers over inland Algeria and Morocco even at low levels considering how warm the Mediterranean is...

[TEITS]

Aye. And, it's starting to worry me...Apart from the far-reaches of FI, there's no sign of any respite, either...

Whats amazing is +384 only takes us to mid Jan with 6 weeks still left of winter. In recent years we have had to wait until Feb before winter even begins.

I must admit if the 12Z verified I would probably welcome a milder spell from mid Jan onwards. Im going to dread my gas/elect bills if this continues! My own fault for paying quarterly.

A mean of -11C is quiet amazing for Cambs.

http://charts.netweather.tv/ensimages/ens.20100102/12/t850Cambridgeshire.png