winter model discussion Winter Model Discussion 06Z 17/02/13 onwards.

[KTtom]

Its almost laughable, low after low in the Atlantic shows the way to Greenland with WAA yet the high blatantly refuses to go there before sinking SE...amazing.

[Ice Day]

Okay, it's one of the 'lesser' models, but the GEM at 108 is very nice and continues this evening's trend (well, let's hope it's a trend anyway!)

[Cheshire Freeze]

Its almost laughable, low after low in the Atlantic shows the way to Greenland with WAA yet the high blatantly refuses to go there before sinking SE...amazing.

Just keep viewing to 144, 168 at a push and watch what transpires.

GFS seems keen on a WB -NAO

CFS keen on a more centrally located or east based -NAO through March.

Either way we're about to see height rises around the Greenland locale. I have little faith in the ensembles at this point.

[mcweather]

Thanks for the couple of Emails I got today-

NAVGEM & GEM in particular look like morphing into EPIC runs tonight although they are just at the 78 stage - everything is alligned very well-

S

Indeed GEM is at 108

[Weather-history]

Its almost laughable, low after low in the Atlantic shows the way to Greenland with WAA yet the high blatantly refuses to go there before sinking SE...amazing.

The problem there is a trough which stretches from Greenland southwards to the east of Newfoundland and a high pressure cell to the west of this near Hudson Bay. I can't see how you can have retrogression in that set-up. The trough needs to be west of Greenland and into Newfoundland, IMO

[Cheshire Freeze]

The problem there is a trough which stretches from Greenland southwards to the east of Newfoundland and a high pressure cell to the west of this near Hudson Bay. I can't see how you can have retrogression in that set-up. The trough needs to be west of Greenland and into Newfoundland, IMO

Indeed, time for changes and alterations though. One thing that strikes me is the repeated attempts, so even if at that time it fails I think there will be success eventually. Perhaps this is what the CFS has picked up over the last 3/4 weeks.

[Barry12]

100 miles North and it's widespread snow for the whole of England, would be a pleasant end to Winter

I have faith the ECM will do that tonight

Edited February 17, 2013 by Barry95

[Ian Brown]

The problem there is a trough which stretches from Greenland southwards to the east of Newfoundland and a high pressure cell to the west of this near Hudson Bay. I can't see how you can have retrogression in that set-up. The trough needs to be west of Greenland and into Newfoundland, IMO

Yes, and this is why 'FI' over the various GFS runs over the last few days, have refused to retrogress the High to Greenland. The UK High will have nowhere to go for some time IMO.

[Mair Snaw]

http://www.meteociel...96-21.GIF?17-17

A shift north from the UKMO & a flow condusive to modest snow showers along the home counties in ~ -11c air.

Also snow flurries in the Southern coastal regions & up towards dartmoor. + Jersey.

S

Good to see you back Mr Murr, with this slight shift north on the 12z i assume that we will be getting your input on the 18z??

Just goes to show that one run is just that... 3/4 south shifts and its end of the world 3/4 north and its party time, thats why i love this forum...

[mcweather]

Hopefully this evenings ECM will continue the trend shown on ukmo raw GEM and GFS and keep the nudging north of the pattern going.

[Ian Brown]

I really wouldn't put faith in the GEM. I've looked at it throughout the winter and it's run to run variability at timescales of even less than 100 hours is alarming.

[Cecil Hogmanay Melchett]

I really wouldn't put faith in the GEM. I've looked at it throughout the winter and it's run to run variability at timescales of even less than 100 hours is alarming.

Shame that Ian its a cracking run!

[Ian Brown]

The T96 charts are OK, the problem comes at around T120-132 when the High makes the connection with the Azores High.

Yes there could be more aggressive troughing over Europe but I don't recall any archive when this troughing has pushed NW when we already have the High in that position with it's Azores link up. Not something I can buy synoptically. But hopefully still some room for manoeuvre in the positioning of the High to bring more of the South into play snow wise.

[kent]

Recent events have shown that these systems have ended with a push north within 48hours. Lets hope this one does likewise. Anyway looking better for the SE and eastern coast at mo. Keep the faith and hope for good news from tonights ECM crucial methinks.

[Jason M]

Slightly better charts in the near to medium term tonight. We may still salvage something from this yet. Just another little tweak north to hopefully bring more of the country into the game.

Remarkable consistency at day 11 within GEFS. 18 of the 20 go for a UK high.

Jason

[PB22]

The GFS operational was one of the, if not the coldest, run for London for a while later this week, also a cold outlier in FI: http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=12&ville=Londres&runpara=0

[chris55]

Some decent trends tonight with the halt to the southward movement of the pattern.

Also something to watch is that the Azores high link up at around 144 may not be a done deal yet! GEFS, and the general Atlantic pattern suggest that we could see more energy heading south east cutting off the link up between the Scandi and Azores high pressure systems, a few shortwaves being throw south east would probably do the trick - and these are rarely picked up at range. This would totally change the evolution by propping up the high for longer with the undercutting energy opening the door to a much better evolution.

Something like the GFS P8

As opposed to the ECM 00z

[Cecil Hogmanay Melchett]

The GFS operational was one of the, if not the coldest, run for London for a while later this week, also a cold outlier in FI: http://modeles.meteo...ndres&runpara=0

im more bothered by the precip xharts paul,even for london they are a desert!

cant help feeling its another agonizingly close call!

[Jason M]

The GFS operational was one of the, if not the coldest, run for London for a while later this week, also a cold outlier in FI: http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=12&ville=Londres&runpara=0

The London snow risk is good though. A five day cold spell is pretty good by usual standards so nothing to be downhearted about.

It will probably change but it does look like a cold spell and then a gentle intro into spring. Something for everyone hopefully...

Jason

[chris55]

The GFS operational was one of the, if not the coldest, run for London for a while later this week, also a cold outlier in FI: http://modeles.meteo...ndres&runpara=0

I think that highlights that way out in FI the GFS's insistence of the Atlantic pushing in may not be as solid as it looks on the ensembles.

[london-snow]

Okay folks having had time to digest the output thus far today i feel quietly confident.

Now this maybe something or nothing but its positive so i will go ahead and explain.

So following on from the 06z GFS which was not that bad of a run especially the further se you are i have viewed the following output :

NOGAPS ~ Excellent run as it sends the high northwards & stops the trend south.

NAVGEM ~ Virtually identical to the NOGAPS & again sends the high northwards thus allowing the main core of cold into england.

12z GFS ~ It has clearly stopped trending south with the placement of the high & starts correcting it further north. Baby steps but a good run.

UKMO ~ Quite similar to the GFS. Good run.

So what can we make of it?

Well until the ecm comes out i think its very good to see the southward placement of that high for the time being has stopped & is just starting to show signs to placing the high further north which is what you are after if you want cold & potential snow.

Think baby steps & hope that the ecm starts placing the high further northwards.

[london-snow]

^^^ precip ensembles are useless unless a attack from the sw is what you're on about.

Things like convective showers or streamers or disturbances will not be picked up by the ensembles & especially at this sort of range.

[PB22]

I think that highlights that way out in FI the GFS's insistence of the Atlantic pushing in may not be as solid as it looks on the ensembles.

I do think the GFS is bringing the Atlantic in too quickly, although it has been very consistent on this for several runs now. But with a mean chart like this at T+240 then it's still a long, long way off:

[BLAST FROM THE PAST]

http://www.meteociel...44-21.GIF?17-17

Snow into England from the Continent- northern extent difficult to say-

S

Indeed Steve, there was an awful lot of 'game over' posts this morning and usually posted on back of one run. 12z nicer and introduces snow chances for many in southern/south eastern regions...and what's to say there won't be a tad further northward correction? These runs also are introducing a prolonging of the cold and not a 'snap' as suggested. Also since when has 7 days been a 'snap'?

BFTP

[Cloud 10]

I'm going to miss the NOGAPS...