Model Output Discussion 18th Nov.2013-12z onwards.

[swfc]

Interesting outputs from the GFS/ECM/GEM et all...I wonder if we'll see some WAA or some SW's to scupper the party...maybe even some MLB & HLB....of course a SSW event could raise hopes...maybe even a plume with an MCS could be on the cards...Of course it all depends what the MJO & NAO combined with the AO and the QBO show...then again, a little bit of CAA interacting with the LLJ could change everything...then again I forgot to factor in the DLS & PWAT...

the moral of the story is to always read the instructions as I do believe I've just overdosed on Model Output acronyms...

I'll fetch me coat!!

 

(site team joke....sorry!)

dont forget that quasi modo thing!!  Anyway not a bad mornings output esp ecm.12z app?the best gfs run of the day so lets seeif it delivers !Slightly less amplified in the atlantic and the pv looking stronger and more westward at 144 hrs on the 12z 

Edited November 27, 2013 by swfc

[Mucka]

GFS goes shortwave crazy in model shocker

 

 

[nick sussex]

What have I missed? Quickly trawled through the outputs to see this is likely to turn into a major nerve shredding outcome. Theres not enough initial amplification upstream so a shortwave is likely to have to run east , then as the Pacific ridge digs towards the Arctic a lobe of lower heights gets thrown westwards to meet up with an amplifying wave in Canada this phases energies which then trundle east forcing more amplification downstream to help the shortwave to cut se near the UK and some weak pressure rises develop over Greenland! easy isn't it!!!

 

Anyways that's what I think is the likely evolution, lets see. We want rid of the high to the south now as that's just a spoiler, the shortwave needs to cut across it.

Edited November 27, 2013 by nick sussex

[Mucka]

MetO GFS 144 comparison

 

[Snowy L]

Eastward shift in this run, with a low pressure system in the Atlantic pushing into the high pressure. Going to be a crazy few days of model watching.

[Bogman]

What have I missed? Quickly trawled through the outputs to see this is likely to turn into a major nerve shredding outcome. Theres not enough initial amplification upstream so a shortwave is likely to have to run east , then as the Pacific ridge digs towards the Arctic a lobe of lower heights gets thrown westwards to meet up with an amplifying wave in Canada this phases energies which then trundle east forcing more amplification downstream to help the shortwave to cut se near the UK and some weak pressure rises develop over Greenland! easy isn't it!!!

 

Anyways that's what I think is the likely evolution, lets see. We want rid of the high to the south now as that's just a spoiler, the shortwave needs to cut across it.

 

 

I think I've seen that film.

[Cheshire Freeze]

Watch the LP tracking SE to the south of Greenland

 

[Joe Levy]

In spite of the eastward shift on this run, I believe (though I could be wrong) that the outcome will be more or less the same from this run, just slightly delayed. When I say the same, I don't mean identical, just the overall idea of a cold northerly should be the same. But we shall see!

[Mucka]

GFS will probably go on to produce a stonking FI after throwing a shortwave spoiler at us, it would be typical,  but I would rather keep things simple than have them get ever more complicated and reliant on small details and the behaviour of (dun dun DUN!) shortwaves.

 

Edited November 27, 2013 by Mucka

[BLAST FROM THE PAST]

Its around t168, look for the depression moving up eastern North America towards southern tip of Greenland, GFS will have that as a cut off low from northward ridging as it rides over the top of the Atlantic HP.  Not that its right, but its what I think the model will show.  UKMO model makes more of the LP moving up eastern flank of N America too.  It could though lead to what ECM was showing come t216/240.

 

BFTP

Edited November 27, 2013 by BLAST FROM THE PAST

[Snowman.]

GFS will probably go on to produce a stonking FI after throwing a shortwave spoiler at us, it would be typical,  but I would rather keep things simple than have them get ever more complicated and reliant on small details and the behaviour of (dun dun DUN!) shortwaves.

 

I don't see any shortwave if it spawns of the main low and digs SE it will only aid it even more.

Edited November 27, 2013 by SN0WM4N

[Cheshire Freeze]

204 hours...

 

[nick sussex]

I think I've seen that film.

If the film has a happy ending we could manage a northerly and ne/easterly flow, if the PV moves back west after the initial northerly then as it does so the ridge topples towards Scandi developing a ne/e flow on its southern flank. What we want is the PV chunk to move west as far north as possible.

[forecaster]

 

GFS goes shortwave crazy in model shocker

 

 

 

 

There's no shortwave troughs evident in that picture.

[SMU]

Usual 12z GFS rubbish at 168- to much Northern energy & flat as a witches T*T.

It will still amplify - reasons explained later- but 144-192 is wrong.

Edited November 27, 2013 by Steve Murr

[Cheshire Freeze]

 

[Paul]

Quick heads up - the Netweather winter forecast will be online later this evening

[frosty ground]

 

Well spotted @190

[Yarmy]

Now that's a Northerly:

 

[Mucka]

I don't see any shortwave if it spawns of the main low and digs SE it will only aid it even more.

 

Then you do see it?

Yes if it tracks SE and if the timing is right it will help. Here it is with its fellow traveller at 144.

 

 

The problem is shortwaves just complicate the picture and give more chances for things to go wrong, if you can guarantee it will behave itself though then I'm in.

[Captain Shortwave]

With the very deep trough developing in the States you have a big window of opportunity to effectively fill your boots. That's one tasty northerly.

Hence why I have a little bit of confidence that we might get something decent from this spell. So despite the complications involving the number spawning lows off the eastern seaboard you still get the Arctic blast at day 10

Edited November 27, 2013 by Captain shortwave

[Cheshire Freeze]

Now that's a Northerly:

 

 

Aye that'd put hairs on ya chest. No marginality in that flow sourced directly from the N Pole

[Cloud 10]

Quick heads up - the Netweather winter forecast will be online later this evening

 

I knew Frosty was working on a secret project. 

[Snowman.]

MetO GFS 144 comparison

 

FI is very close UKMO has barely anything in Canada.

 

Wonder what the UKMO would look like if it went further.

[Summer Sun]

After the northerly we have the Atlantic high winning out in the end, no doubt about it though it turns cold maybe even very could for a time once more from GFS before milder air wins out

 

Edited November 27, 2013 by Summer Sun