Model Output Discussion - The final stretch to Christmas

[bluearmy]

btw, i think that was the first run to show an actual SSW !  it will be close. 

[nick sussex]

Lol! Oh dear poor old GFS! You can always rely on it to go from one extreme to another, anyway at least we look to be edging towards agreement on the low at T96hrs.

 

Are you all ready now for the next piece of the easterly puzzle? 

 

Theres a lot of uncertainty with a Gulf of Mexico shortwave and the speed/ depth effected by the amplitude of the pattern over in the western USA. You'll note that the GFS P is now flatter, the GFS more amplified this of course effects low heights near the UK and how far east and se these get.

 

Briefly this is expected to run ne and NCEP haven't a clue at this point how much it might develop and its exact track ie coastal, inland , this shortwave really tells us how amplified the ridge is over in the western USA, so its like a marker for a possible easterly, anyway I promised I wouldn't go into this tonight, enjoy the GFS, its a lovely run and it owed us something after causing much consternation in here earlier!

 

More on this tomorrow, I suspect pandemonium has broken out due to the GFS being abducted by Santa!

Edited December 23, 2014 by nick sussex

[Yarmy]

My forecast from 10 days ago of cold from the 28th is still playing out beautifually.

 

Stage 1 - Snow from the fleeting Northerly (locations impossible to forecast as yet)

Stage 2 - Uk high preserving the cold and snow

Stage 3 - Scandinavian heights - Good to see the trend grow

Stage 4 - The relocated Pv over in Canada to undercut the block as it sends energy south in the atlantic

 

***** For stage 4 its important to understand that no model has the ability to forecast the undercut from T-300 or even T-192.......so be patient once this stage hits the reliable watch the Scandinavian High send the jet stream and low pressures further and further south and under.... All FI is futile at the minute. Ignore the output

Hmmm...I think I will be paying close attention to Mr Ingham's posts from now on.

[Allseasons-Si]

btw, i think that was the first run to show an actual SSW !  it will be close. 

Do you meen this Ba,this look astonishing.

 

Edited December 23, 2014 by Allseasons-si

[Nick F]

Talk about one extreme to another, GFS op was the loner but decided to join the Euro party and now's the centre of everyone's attention on the dance floor!

Key to the change in behaviour is more amplification upstream over the mid-Atlantic early next week. With the block developing over N Europe but still a lot of energy pushing east upstream due to the deep polar low over Greenland and northern Canada the strong jet is eventually forced mostly under the block but as part of split flow over and under.

Interesting u-turn from GFS, let's hope the 00z suite keeps the theme of keeping Atlantic mobility at bay next week.

Oh, and updated t+96 fax keeping in line with UKMO GM track with the low SE down East coast. No going back for GFS now?

Edited December 23, 2014 by Nick F

[SMU]

Evening All.......

 

 

Well Apologies for my absence in the last 24 hours- Xmas work & all that, 1 more day to go.

 

 

Since there was a Twinkle in the GFS eye some 9 days ago for day 14/15  we have been traversing a tricky path to a longwave pattern change, at times its seemed pretty fruitless with man many downgrades , however in the mix now is the potential upgrades- I mentioned this the other night.

 

The teleconnector to a -EPO ridge over Alaska is an atlantic ridge. Because the -EPO ridge supports a huge dig in the jet over the Eastern part of the US it then supports a returning flow North up towards the pole, but also supports a more sustained MLB somewhere close to Norway.

 

As usual with this protracted pattern the GFS has had many helpings of progressive spirit not wanting budge, where as the ECM has tentatively throwing the ridge NE but not really getting there with the heights to the correct latitude.

Impressively the UKMO was the first model to point to a NE flow from the storm tracking SE. It changed its output yesterday 12z.

 

http://www.meteociel.fr/ukmo/archives/2014122212/UW144-21.GIF?22-12

 

Since then the models have followed, & upgrades in terms of longevity of cold have trickled in with it.

 

This evening these have translated from a trickle into a flood from the pub run suddenly picking up this ridge pattern & running with it. ( GFS p slightly behind the curve but not to far )

 

just to emphasize the swing 2 charts below from the GFS  - 12z 180 V 18z 174

 

12z

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2014122312-0-186.png?12

 

18z

http://modeles.meteociel.fr/modeles/gfs/runs/2014122318/gfsnh-0-174.png?18

 

Impressive..... Especially the more South & east you live..

 

 

So things on the downward trend for the end of December, signified by the pattern change that starts tonight/ tomorrow.....

 

Finally some weather porm- adults only.

 

T 138 ONLY

http://www.wetterzentrale.de/pics/Rmgfs1382.gif entering the SE

 

T 150    -11 in the SE & -16 not far away.

 

http://www.wetterzentrale.de/pics/Rmgfs1502.gif

 

T2M temps

http://www.wetterzentrale.de/pics/Rmgfs1624.gif & theta E

http://www.wetterzentrale.de/pics/Rmgfs1449.gif

 

so then, potentially things becoming interesting for the end of Dec starting tomorrow & optimism rising for the start of 2015-  remember the ensembles will be slower to react & further upgrades are distinctly possible........

 

ciao

S

[bluearmy]

Do you meen this Ba,this look astonishing.

 

gfsnh-10-384.png

 

 

no, this - although on reflection, perhaps is isnt quite there.  should do the job though and the whole strat vortex is split top to bottom by the end of the run

[Allseasons-Si]

Hmmm...I think I will be paying close attention to Mr Ingham's posts from now on.

 

Yes Yarmy

 

i had the same idea at the beginning of the thread,post 5

 

https://forum.netweather.tv/topic/82079-model-output-discussion-the-final-stretch-to-christmas/

[Man With Beard]

Incredible... 10c change in the South/South East.

It's all going one way today and very quickly! This easterly has come from nowhere, hats off to the likes of TEITS who predicted it a few says ago (assuming it does actually happen of course!!!).

Weather lesson 15987 relearnt: Don't take the model output as gospel beyond T144 - big changes can always come out of nowhere. Especially when ANY type of heights gets north of our latitude in our vicinity, even teeny weeny ones.

[Severe Siberian icy blast]

Warmings from start to finish becoming stronger throughout the run , great split through fi aswel , with the final frame showing this

Feeling much more positive for January now , wonder why Judah Cohens was down beat the other day ? Did anyone read his blog ? I haven't been able to find it !

[Mark Neal.]

Warmings from start to finish becoming stronger throughout the run , great split through fi aswel , with the final frame showing this image.jpg

Feeling much more positive for January now , wonder why Judah Cohens was down beat the other day ? Did anyone read his blog ? I haven't been able to find it !

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

Interesting Strat updates showing in the models, Lorenzo and BA have some good posts in the Strat thread tonight- https://forum.netweather.tv/topic/81567-stratosphere-temperature-watch-20142015/page-43#entry3095798

[Captain Shortwave]

Good agreement on the track of the low (South east through the UK most likely), still some uncertainty on the exact track. But how cold the north easterly will be will be determined on where the high manages to build in. The GFS gets it into Scandinavia and sets up a very cold flow for the south eastern third of the UK. The ECM centres the high over Scotland which results in surface cold with mixed out 850s. A lot of interest as we move through Christmas with the potential for cold or very cold conditions to develop as we go into the New Year.

Edited December 23, 2014 by Captain shortwave

[steveinsussex]

Hmmm...I think I will be paying close attention to Mr Ingham's posts from now on.

 

Its a fantastic post and prediction, credit where its due to him.... although yet to come off of course

[Joe Levy]

Lovely 850 temp average from the 18z ENS 

Edited December 23, 2014 by Joe Levy

[blizzard81]

Well, I don't know about anyone else but what a great time for these upgrades to appear. Two days before Xmas and we

have a lot to look forward to in the next few days. I for one am hoping for upgrades in the next 24 to 48 hours.

On a side note, over the years, it has been mentioned that the models suffer some date shortages over the

xmas period. Was this ever the case? And is so, is it still the case ?

[Mair Snaw]

Right guys n gals we are all getting very excited..... but please for the love of COLD we are not to mention this to anybody.... nobody no matter how close they may be to you under no circumstances are we to say anything not until t24.... and nothing to the kids until t0.....

[Tim Bland]

[quote name=

Feeling much more positive for January now , wonder why Judah Cohens was down beat the other day ? Did anyone read his blog ? I haven't been able to find it !

[JOPRO]

Right guys n gals we are all getting very excited..... but please for the love of COLD we are not to mention this to anybody.... nobody no matter how close they may be to you under no circumstances are we to say anything not until t24.... and nothing to the kids until t0.....

And Whatever you do don't tell the express!! Hopefully they will be running a headline about the warmest winter on record being forecast tomorrow!!!

Edited December 23, 2014 by JOPRO

[Neilsouth]

Its a fantastic post and prediction, credit where its due to him.... although yet to come off of course

 

Link to his posts? Cheers

[Jason M]

So much for the northerly :-)

We're not there yet though. GEFS are starting to move over, but margins for error are fairly small so more runs needed. As I've been mentioning for a whole though, pressure rises to our NE is at least logical. I'm a bit surprised how far things have moved with the pub run though as my gut feeling was a close but no cigar scenario. The mornings runs will be eagerly awaited (as will any insights from Fergie this evening).

So an easterly and the return of 'Murr' (which given the season seems somehow appropriate). What can possibly go wrong :-)

[SMU]

Pretty much every GFS ensemble at 144 has switched to a scandi high varying in Lattitude, so all cold at the surface - but with warmer uppers.

 

Interesting is the Control - almost 100% identical to the Operational with the -10c isotherm into the by 138 identical timeframe as the OP

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=0&mode=0&carte=0

 

S

[J10]

So much for the northerly :-)

We're not there yet though. GEFS are starting to move over, but margins for error are fairly small so more runs needed. As I've been mentioning for a whole though, pressure rises to our NE is at least logical. I'm a bit surprised how far things have moved with the pub run though as my gut feeling was a close but no cigar scenario. The mornings runs will be eagerly awaited (as will any insights from Fergie this evening).

So an easterly and the return of 'Murr' (which given the season seems somehow appropriate). What can possibly go wrong :-)

 

An awful lot as you well know.

[Allseasons-Si]

Link to his posts? Cheers

 

Here you go TS

 

https://forum.netweather.tv/topic/82079-model-output-discussion-the-final-stretch-to-christmas/page-27

 

POST 538 :smiliz19:

 

credit to him,i look forward to his details in the future,not discounting all other experienced folk on the forum of cause :smiliz19:

Edited December 23, 2014 by Allseasons-si

[blizzard81]

I don't know about anyone else but I've had a terrible year lol! An easterly to finish it off would make

up for it in some way though :smiliz19: GFS ensembles have switched, surely all systems go and the

only question is how cold and yes dare I say, how snowy?

[Nick L]

One set of runs and we're already back slapping? There's a long way to go folks.