Model Output Discussion 12z 07/11/2012

[Nick F]

So the status quo continues on tonight's runs wrt to the trough sitting to our W and NW for at least the next 8-10 days, while we see a +ve height anomaly to the east over eastern Europe. This is shown nicely by the CPC 6-10 day 500mb forecast and also the ECMWF ensemble mean at t+240.

A lot of convincing needed, going by model output trends over recent days, to suggest we will get out of this pattern quickly. Though very recent winters have shown that the PV has been less inclined to camp it out all winter over Greenland, unlike those +ve NAO winters of the late nineties and early noughties.

[snowking]

12z ECMWF control attempts to build the block NWwards as per its 0z output, however too much energy heads into the northern arm of the jet and LP comes steamrollering through

WIll be very interesting to see the ECM 32 day tomorrow and see if it sticks with the trend for blocking or reverts to something more zonal (I remember such an instance back in Jan/Feb)

But in fairness the ECM 32 has always suggested this change to occur into the first week of december, and not the last week of november.

SK

[Zenarcher]

Within the 120 hour time frame on the GFS 18z you can see it's pushing the low crossing the Atlantic more South just like on the ECM. Will be interesting to see if this makes any changes later in the run.

[damianslaw]

A typical mid November outlook, rather drab it has to be said with alot of cloud, drizzly rain, murky conditions with some fog thanks to winds falling light as the week wears on - in other words the worst side of November... but its rare not to see such conditions during some part of November.

Day to day conditions will vary, tomorrow looks a mild cloudy dull day with some heavy rain in SW Scotland, Wednesday an equally drab affair with slightly above average temps. Thursday should see a mostly dry day for all, but could be quite chilly thanks to misty foggy conditions especially in central southern parts.

The end of the week looks likely to bring rain in from the west but again it will be a rather lacklustre band of rain, with just a sprinkle in eastern parts with temps at or slightly above average.

The models all show the trough becoming very slow moving medium term edging slightly to our east maintaining the rather mild conditions as heights remain strong over eastern europe. However, none of the models are showing a ramping of the polar vortex anytime soon, the atlantic continues to be a very weak influence given the time of year when it really should be moving into fifth gear and if we maintain strong heights to our east and the current longwave trough position it wouldn't take much for much colder continental air to invade from the east kicking the trough into touch.. so I can see alot of credence in some of the current forecasts going for a much colder end to the month, it looks a much more plausible outcome than a raging zonal express train..

[Ice BIast]

Interesting, the LP in the atlantic looks like it would stall and send WAA north.

A better run from the GFS IMO.

[SMU]

http://modeles.meteo...nh-0-192.png?18

GFS slowly edging along-

Great vertical WAA retrograding west ....

S

Edited November 12, 2012 by Steve Murr

[chionomaniac]

The H shaped vortex

Never a bad thing.

[SMU]

• http://modeles.meteociel.fr/modeles/gfs/runs/2012111218/gfsnh-0-264.png?18
  

11 days & how things can change once we get the right retrograde....

it will probably take 3 goes-

S

[Ice BIast]

Interesting, the LP in the atlantic looks like it would stall and send WAA north.

And indeed it does, resulting in this nice looking chart:

[blizzard81]

http://modeles.meteo...nh-0-192.png?18

GFS slowly edging along-

Great vertical WAA retrograding west ....

S

Shame it's the pub run and couple this with the ECM seemingly jumping ship for now - just viewed the ECM 12z ensembles.

[Cheshire Freeze]

Ooooohhh Matron!

[Ice BIast]

If only!

[Snowy Easterlies]

Wow GFS 18z is hammered tonight best run of the season so far, and its still autumn

shame it all in FI

[blizzard81]

• http://modeles.meteo...nh-0-264.png?18
  

11 days & how things can change once we get the right retrograde....

it will probably take 3 goes-

S

Looks like a much sweeter version of the ECM 12z operational run - That cross polar ridging is eerily similar to the ECM 240 chart.

Just wish this was the GFS 12z and not the much derided pub run.

[Zenarcher]

Just goes to show that the powerful low on the 12z wasn't great for our long term outlook,

20th

12z

18z

Despite their differences both FI's have a trend of a blocked pattern finishing off November. 18z FI looks better to me in the Northern hemisphere more blocked.

[conor123]

http://www.wetterzentrale.de/pics/Rtavn3602.png

And the dream chart of the year appears.

[cold snap]

gfs at 324 astonishing.brillaint run for coldies ,vortex split right down the middle

gfs at 324 astonishing.brillaint run for coldies ,vortex split right down the middle

[ITSY]

still some negativity across these threads atm - the pattern is of an emerging cold theme towards the months end, in time for the start of winter, what more could we ask for? (for it to happen, is the obvious answer). Best run of the season so far. I don't buy this 'pub run' suggestion that the 18Z is any less valid than the others, or that the ECM is backing away. Chops and changes are inevitable at this range so let the models sort themselves out and come back in a week if people can't handle the topsy turvy nature of UK winters.

lets see where this is on the ensembles. bound to be on the cold side, but its level of support and the placement of the control will be interesting

Edited November 12, 2012 by ITSY

[snowking]

The 18z evolution very similar to the nov/dec 2010 evolution

archivesnh-2010-11-15-12-0.png

archivesnh-2010-11-16-0-0.png

archivesnh-2010-11-16-12-0.png

archivesnh-2010-11-17-0-0.png

archivesnh-2010-11-17-12-0.png

I always find it quite magical when HP seems to appear from nowhere.

The H shaped vortex

Never a bad thing.

Apparently it means HLB...

SK

[EML Network]

I just spat my tea out, from an IMBY perspective, this is the holy grail..if ONLY this was in the reliable time frame. !!

[Fred Sykes]

http://www.wetterzen...s/Rtavn3602.png

And the dream chart of the year appears.

Yes, I think I just had a modelgasm

[SMU]

http://modeles.meteociel.fr/modeles/reana/2010/archivesnh-2010-11-21-0-0.png

21 st Nov 2010 the pinnacle chart that sets a set of events rolling ( the split flow est of greenland )

http://modeles.meteociel.fr/modeles/gfs/runs/2012111218/gfsnh-0-216.png?18

21 st Nov 2012 the possible pinnacle chart setting another events rolling.....

S

[blizzard81]

still some negativity across these threads atm - the pattern is of an emerging cold theme towards the months end, in time for the start of winter, what more could we ask for? (for it to happen, is the obvious answer). Best run of the season so far. I don't buy this 'pub run' suggestion that the 18Z is any less valid than the others, or that the ECM is backing away. Chops and changes are inevitable at this range so let the models sort themselves out and come back in a week if people can't handle the topsy turvy nature of UK winters.

Not a case of not handling the topsy turvy nature of UK winters. Just stating a fact that the ECM 12z ensembles are a big

dissapointment for cold fans this evening. If we are to see a trend, the best indicator is the ECM ensemble suite and certainly not the 18z.

[Snowy Easterlies]

stonking run, amazing seeing those cold uppers reach us, after the continent has been so warm, its nov 2010 all over again,

must not get carried away, what would ian brown say about this run ?

Edited November 12, 2012 by Snowy Easterlies

[Met4Cast]

Well, I think its safe to say the 18z has picked up on the potential Scandi High Signal and has gone to town with it. Absolutely astonishing charts!

I largely expect it'll be gone tomorrow and almost certainly it's going to be a cold outlier, but absolutely fantastic to see nonetheless!