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

[legritter]

a good run so far gang ,as i said hang on in there its still early days but we,v just been delt a good run .snow only along M4though so its snow on west carriageway bone dry on east side ,at least highways will save money on grit being just one side .just a laugh but looking foreward to tonights late fax ,catch up later .

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013021712/ECH1-240.GIF?17-0

At 240 my initial thought was a sinker- but if we look- greenland has cleared of the JET & the atlantic has great vertical advection.

Also a trigger low neatly lined up east of greenland to recurve over us.

The models have granted me a stay of execution tonight-

Looking good this week, I would say 3 ice days on the bounce for me & very very close elsewhere......

I will be interested in both Ians thoughts on the 12's more particular the shower train potential....

S

[Jason H]

ECM keeps the theme going. Increasingly colder for all throughout the week with increasing risk of snow for England towards next weekend. Also signs that the High Pressure want to migrate North. Interesting week ahead.

[Cheshire Freeze]

HP moving NW too so cold should prolong....those of little faith

BFTP

Cold air piling into Russia, warm air piling into Greenland, high temporarily sits over UK at 240 hrs. Could be worse evolutions......

Edited February 17, 2013 by CreweCold

[TEITS]

One thing that catches my eye is that a atlantic attack is looking more and more non existant than was first thought.

Attack from the SW has been pretty much none existant these past few days.

I will add its going to be difficult to maintain any snow cover due to the time of year regardless of temps. For this to happen locations are going to need plenty of cloud cover and little sunshine.

Personally im not bothered about days of lying snow or how prolonged this cold spell could be. I would be content with a few days of snow showers and anything else is a bonus.

[cold snap]

http://www.meteociel.fr/modeles/ecmwf/runs/2013021712/ECH1-240.GIF?17-0

At 240 my initial thought was a sinker- but if we look- greenland has cleared of the JET & the atlantic has great vertical advection.

Also a trigger low neatly lined up east of greenland to recurve over us.

The models have granted me a stay of execution tonight-

Looking good this week, I would say 3 ice days on the bounce for me & very very close elsewhere......

I will be interested in both Ians thoughts on the 12's more particular the shower train potential....

S

The frustration has been all winter not getting the high to Greenland , this looks like are best chance .

Thanks for your excellent posts

[Severe Siberian icy blast]

HP moving NW too so cold should prolong....those of little faith

BFTP

The natural progression there would be for the low pressure to undercut the high and strengthen the block and the easterly at the same time.

The last chart doesn't look plausible with the Azores taking a massive leap north

[Cheshire Freeze]

http://www.meteociel...H1-240.GIF?17-0

At 240 my initial thought was a sinker- but if we look- greenland has cleared of the JET & the atlantic has great vertical advection.

Also a trigger low neatly lined up east of greenland to recurve over us.

The models have granted me a stay of execution tonight-

Looking good this week, I would say 3 ice days on the bounce for me & very very close elsewhere......

I will be interested in both Ians thoughts on the 12's more particular the shower train potential....

S

Yep, very true Steve. High temporarily sits over UK but looking at the bigger picture it's loaded with potential. Look to NW would be a good hint if the run went out further because I'm sure that's where the high would be headed.

[johnny1972]

HP moving NW too so cold should prolong....those of little faith

BFTP

Blast

The issue I wud have is there needs to be retrogression of the H/P towards the NW to allow the PV to drop down into Scandinavia and towards the UK. Simply the coldest uppers are well locked in in the artic / Scandinavia and can't extend into Europe due to the HP extending across towards Russia and blocking the coldest flow to Europe. Therefore the cold uppers in Europe are eroded relatively quickly. Yes the set up is good for the east / SE and south but the pattern is too marginal for western areas should any moisture enter the flow. It has been like this all winter. Dry, cool and sunny IMHO.

Regards

Johnny

[chris55]

Poised!!!

[snowflakey]

Roughly 500 height-((SLP-1000)*0.8

so ~ 520 DAM

steady as she goes at 168......

S

Thanks Steve Ill try and remember the Formula. Sorry mods slightly off top.

[Eskimo]

Poised!!!

Corr if that High drifted a smidge further north, then...

[BLAST FROM THE PAST]

http://www.meteociel...H1-240.GIF?17-0

At 240 my initial thought was a sinker- but if we look- greenland has cleared of the JET & the atlantic has great vertical advection.

Also a trigger low neatly lined up east of greenland to recurve over us.

The models have granted me a stay of execution tonight-

Looking good this week, I would say 3 ice days on the bounce for me & very very close elsewhere......

I will be interested in both Ians thoughts on the 12's more particular the shower train potential....

S

I like my position just south of the North Downs Steve too. A very nice and timely slight shift north this evening, and am not surprised...RJS mentioned that the retro movement this year would be from a higher latitude, thus cold chances pushing right through UK and Ireland look good. My own viewpoint and method FWIW is that we'll see some very short time snow enhancement reports come weekend and the colder showing synoptic will be closer to mark than watered down showing.

BFTP

[cold snap]

Yep, very true Steve. High temporarily sits over UK but looking at the bigger picture it's loaded with potential. Look to NW would be a good hint if the run went out further because I'm sure that's where the high would be headed.

Been saying that all winter crewe , lol

The profile in the northern hemisphere looks very good for the end off February ,to see major cold once again reinforced into Russia is good news .

This will be are last chance over the next 2 weeks , still in the game

[Purga]

http://www.meteociel...H1-240.GIF?17-0

At 240 my initial thought was a sinker- but if we look- greenland has cleared of the JET & the atlantic has great vertical advection.

Also a trigger low neatly lined up east of greenland to recurve over us.

The models have granted me a stay of execution tonight-

Looking good this week, I would say 3 ice days on the bounce for me & very very close elsewhere......

I will be interested in both Ians thoughts on the 12's more particular the shower train potential....

S

ECM 240 looks a bit 'dodgy' for longevity and could easily go down the tube to me Steve but I bow to your greater knowledge on this one.

[Snowy Liverpool]

http://www.meteociel...H1-240.GIF?17-0

At 240 my initial thought was a sinker- but if we look- greenland has cleared of the JET & the atlantic has great vertical advection.

Also a trigger low neatly lined up east of greenland to recurve over us.

The models have granted me a stay of execution tonight-

Looking good this week, I would say 3 ice days on the bounce for me & very very close elsewhere......

I will be interested in both Ians thoughts on the 12's more particular the shower train potential....

S

Yes this might be one of the few times in history where a shortwave actually helps us instead of ruining everything.

[BLAST FROM THE PAST]

Blast

The issue I wud have is there needs to be retrogression of the H/P towards the NW to allow the PV to drop down into Scandinavia and towards the UK. Simply the coldest uppers are well locked in in the artic / Scandinavia and can't extend into Europe due to the HP extending across towards Russia and blocking the coldest flow to Europe. Therefore the cold uppers in Europe are eroded relatively quickly. Yes the set up is good for the east / SE and south but the pattern is too marginal for western areas should any moisture enter the flow. It has been like this all winter. Dry, cool and sunny IMHO.

Regards

Johnny

It certainly won't be cool...trust me.

BFTP

[bradymk]

Yes this might be one of the few times in history where a shortwave actually helps us instead of ruining everything.

You would be surprised how many do help us, just they get a lot of bad press. You could say that the shortwave in Italy is helping us get a straight Easterly out of this too. Edited February 17, 2013 by bradythemole

[goosey007]

Nice to read some constructive model related posts. Thanks guys.

The trolls are crying into their roast dinners instead of posting one liners on here, because the 12z has not pushed things further south and upgraded slightly instead!

Steve M / TEITS / Nick S / Crewe cold - love your posts guys :-)

think snowking deserves a mention aswell......cracking analysis by all five this winter fair play

[shotski]

Yep, very true Steve. High temporarily sits over UK but looking at the bigger picture it's loaded with potential. Look to NW would be a good hint if the run went out further because I'm sure that's where the high would be headed.

I think so to crewe but this would fly in the face of what the Meto are currently thinking.

They go for the high to drop SE in time, we will see.

[BLAST FROM THE PAST]

ECM 240 looks a bit 'dodgy' for longevity and could easily go down the tube to me Steve but I bow to your greater knowledge on this one.

If it turned out like that, and looking at the movement to get to that point then this would be my view on what would happen. Our HP has moved NNW to get where it is. The LP/SW between Iceland and Svalbard will move one way, down the western flank of the PV to our E probably down Norway or even further west along E North Sea. The LP in Atlantic to our west, vertical sheer, it is not exerting an influential eastward push on our HP, it would likely start to slide as our HP moves NNW.

BFTP

Edited February 17, 2013 by BLAST FROM THE PAST

[Cheshire Freeze]

Been saying that all winter crewe , lol

The profile in the northern hemisphere looks very good for the end off February ,to see major cold once again reinforced into Russia is good news .

This will be are last chance over the next 2 weeks , still in the game

The issue is that there has been an underlying predisposition (certainly since early/mid Jan) for heights to attempt to rise to our NNW; the models have picked up on this time and time again. Both teleconnections and NWP modelling has intimated as such. However, the location of that vortex segment has nullified this signal and as a result heights have attempted and been shunted east,resulting in ridges and wedges of heights to our E/NE instead owing to a increase in jet energy directly as a consequence to the Canadian vortex spitting off bits of energy into the Atlantic.

FWIW I expected us to be seeing height rises more prominent around Greenland for this coming week (stated this around first few days of Feb). However yet again this hasn't been the case. We once again see heights rise to the ENE. Thisis what occurs when you have a jet (fuelled by proximity of vortex to N Atlantic sector) which splits and halves its energy N&S as opposed to sending most of the energy into the southern arm or deflected far enough to the N far enough W of the UK to construct an omega type block. Ridging to the E was the only possibilty in this instance however.

I'm still very much of the opinion that we will get there eventually as the recurrent pattern looks like perpetuating itself into March; the main difference being the energy to the NW has waned and thus opens up a slightly bigger pandora's box of possibilities.

I'll leave you with this (consistent) CFS anomaly for March

Edited February 17, 2013 by CreweCold

[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.

Not a bad piece of guesswork & with the ecm now on board with stopping that high going south & trending it further north i feel that we are now firmly back on the hunt for snow & not just exclusively to south eastern areas.

[Jason M]

Good ECM tonight, very good uppers.

Uppers of -11 ton-12c and pressure over the south of 1015, gives people a shout at seeing some white stuff.

Dont worry about uppers being mixed out, thats inevitable in the second half of feb, and reloads will always be needed.

Jason

[swfc]

Not a bad piece of guesswork & with the ecm now on board with stopping that high going south & trending it further north i feel that we are now firmly back on the hunt for snow & not just exclusively to south eastern areas.

good call there.you should join the meto!