Model Output Discussion - Tuesday 20:25 -->

[SNOWPLOUGH]

The models are full of massive potential.

We must respect the intensity of the cold pool to our east.

http://www.wetterzentrale.de/pics/Rtavn1442.png

I strongly believe the power of this Arctic high is being underplayed by most if not all models.

I think by the end of next week we could well be shovelling ourselves out of our homes in an historic freeze.

Things will begin to move fast towards the weekend modelwise.

I would tend to agree with the historic freeze evolution, but if we see the ugly side of shortwaves, the set-up will go the way of the pear!

SP

[Mark H]

Past experience should have taught us not to get too excited by the models, I am sure they will change/downgrade before we have to shovell ourselves out.

But past experience gave us this,

http://www.wetterzentrale.de/archive/ra/1987/Rrea00119870107.gif

Which then led to this,

http://www.wetterzentrale.de/archive/ra/1987/Rrea00119870112.gif

A long way to go but i couldnt help myself

[pyrotech]

The 18z Gfs has constantly played down the cold compared to its other runs for the last 4 days.

The positive point is 3 out of the four daily GFS runs go for cold and so does ECM and UKMO short term.

This will be a will it wont it scenario 24 hrs out. So much can go very wrong or right for the UK with this setup.

Although positive still, it could be the 18z which is showing the closest to what will happen and the other runs overplaying the sweep westwards of cold air.

Europe will get the cold air, its a starting block for us which the models will have dificulty forecasting. What ever happens beyond the cold getting deep into Europe its a massive upgrade from the last few weeks. a cold Europe would make me optimistic for early 2010.

i suspect that the 06z will have us crazy again tomorrow, alot more swings and roundabouts before this is settled.

Its been said before not to follow one models different runs, compare same runs.

[AderynCoch]

I'm fairly new to this model-watching lark.

Is it me or has the GFS completely collapsed past the 300 mark? All I see is westerlies. At least it being a while off makes it less reliable.

Edited December 9, 2009 by AderynCoch

[SMU]

i'll be very happy for a cold spell,anything to firm the gound up at present.

Totally model related-

ramp of the century-

Joe Bas tardi

Steve

Edited December 9, 2009 by Steve Murr

[SP1986]

Indeed Steve, indeed...

Say, does anyone know how to translate Chinese?

more specifically this (which came up on Steves link) or is this part of a joke I am missing?

万网首页 域名注册 虚拟主机 主机托管 企业邮箱 网站建设 网络营销 语音通信 客服中心

　　1、域名只解析，没有绑定；

　 2、域名绑定失败；

　 3、管理员暂停了站点。

　　本页面为系统默认页面，如果网站管理员只进行了域名解析，但没有绑定域名，那么需要网站管理员登录虚拟主机控制面板进行域名绑定操作。进行主机域名绑定，必须保证域名已经备案成功，才能绑定生效，否则将绑定失败。

　　如果该站点是暂停的，需要网站管理员登陆虚拟主机控制面板开启站点。

　　ICP网站备案是建立网站的重要前提，请您在发布网站前务必做好备案工作，具体信息请登录万网ICP网站代备案系统了解。

　　按工信部要求，在万网新购主机、速成网站产品都必须先进行网站备案才能使用，如果不备案，将无法使用。发布网站前，请您务必确保您要使用的域名已经成功通过网站备案，如果网站备案不成功，那么您的域名将无法访问网站。

[SMU]

Indeed Steve, indeed...

Say, does anyone know how to translate Chinese?

more specifically this (which came up on Steves link):

万网首页 域名注册 虚拟主机 主机托管 企业邮箱 网站建设 网络营销 语音通信 客服中心

　　1、域名只解析，没有绑定；

　 2、域名绑定失败；

　 3、管理员暂停了站点。

　　本页面为系统默认页面，如果网站管理员只进行了域名解析，但没有绑定域名，那么需要网站管理员登录虚拟主机控制面板进行域名绑定操作。进行主机域名绑定，必须保证域名已经备案成功，才能绑定生效，否则将绑定失败。

　　如果该站点是暂停的，需要网站管理员登陆虚拟主机控制面板开启站点。

　　ICP网站备案是建立网站的重要前提，请您在发布网站前务必做好备案工作，具体信息请登录万网ICP网站代备案系统了解。

　　按工信部要求，在万网新购主机、速成网站产品都必须先进行网站备案才能使用，如果不备案，将无法使用。发布网站前，请您务必确保您要使用的域名已经成功通过网站备案，如果网站备案不成功，那么您的域名将无法访问网站。

Roughly translated it means-

He who believe 18z operational should-

1) Look at ECM ensembles

2) Rememeber its the pub run-

3) all warm runs have data missing.....

Ai daniel son.....

PS link is for Accuweather- joe Bast rdi european video / model update-

Edited December 9, 2009 by Steve Murr

[peterf]

or could it be http://www.accuweather.com/video-on-demand.asp?video=44795589001&title=Dec.%2015-25:%20You%27re%20Freezing%20if%20You%27re%20in%20Europe

[NorthYorksWeather]

This run looking better at 120 hours with the centre of the high over Iceland rather than the UK, does anyone know what time the ensembles are coming out? 18z ensembles were superb with most showing an easterly as the favourite outcome

[SMU]

This run looking better at 120 hours with the centre of the high over Iceland rather than the UK, does anyone know what time the ensembles are coming out? 18z ensembles were superb with most showing an easterly as the favourite outcome

Morning All-

00z 330-430

00z (p) 400-500

Ensembles 445-530....

Yes I stayed up yet again to watch the GFS 00z-

A couple of bits - the first phase of WAA is well & truly nailed for the UK- within the range T48- 72-

Its not going to change now- So we will get a colder filter of air from the continent-

The main talking point that leads to this..

OMG FAINT....

http://91.121.94.83/modeles/gfs/run/gfs-0-156.png?18

is the NH jet profile over greenland at 120--- theres a startk difference between 18z & 00z - THis is critical to get a high over greenland with backing Easterlies as opposed to the 18z-

We will NOT get strong easterlies until we get a cut off jet over NE greenland - this is what to look for-

http://91.121.94.83/modeles/gfs/run/gfsnh-5-132.png?0

Notice how theres a cut off to the jet over NW scandi- its like closing the door on the last shortwave through to allow ridging to build NE- as a result that will stretch the high orientating it more towards the NE- the southern flank then elongates back more SW-

& then all hell brakes loose------ 100% chart of the day at only day 6............

http://91.121.94.83/modeles/gfs/run/gfs-0-168.png?0

Im going to bed-

S

[David-kig]

that is one gd run the upper cold best ive seen on gfs ever!!!!!! that is just spot on for uk if im looking at it right

[PersianPaladin]

T180+

Is this a -40 isotherm I see before me?

[David-kig]

280 on wards goes down hill but before that blimey thats cracking. fl in bound to change wasn't expecting that not bad have to admit. i don't really get what happens late on in fl seems bit werid. that my friends is a gd run i think

T180+

Is this a -40 isotherm I see before me?

i think so i wasn't expecting that myself that was just best.

[Roger J Smith]

Confucius say -- GFS go back to default zonal even with 62-63 pattern evolution.

I am not sold on the cold outbreak yet, leaning to it of course ... but what happens after about day 10 is pure default, there would be no upstream signal to change the blocking as quickly as this run does. In other words, could turn cold and stay cold. Would suggest any relaxation (if the cold develops) would be after Christmas, closer to 29-30 Dec.

The weather "over here" is absolutely stupendous -- major blizzard over the central states, bombing to 970 mbs in Michigan by 12z. Thicknesses to 466 dm near Great Slave Lake heading south with mini-PV heading for Lake Superior to guide the way. Yet the flow is not collapsing across the southern US, setting up a strong baroclinic zone for next 7-10 days.

Anticipate that parts of the Great Lakes low will try to circle around through the west Greenland Baffin sector to Hudson Bay over that time frame, keeping a strong high over the Greenland - Iceland sector by days 6 to ???

Retrograde index peaks late December -- it's all there to assemble.

[cooling climate]

An excellent run from the UKMO with post t144 bitterly cold air to flood the country.

The ECM should be an excellent run this morning making the arrival of winter for

next week a lock.

[West is Best]

A really excellent 0z GFS run. We sometimes get ticked off for comparing charts with the one-in-a-century winters, and with reason, but this GFS run is unquestionably like the archive charts for 1947. Here's one then:

And T144 GFS:

The problem is that the first of those happened, whilst the second is still just a projection. T144 isn't nailed yet and we should still be cautious. Hopeful, but cautious.

[PB22]

A rather different output this morning from the UKMO 00z run, and there are subtle changes on the GFS ensembles too. For me this is now trending in one direction, and thats for northern blocking to dominate, but for us in the UK we will still be under the Atlantic influence:

http://www.wzkarten.de/pics/Rukm1201.html

http://www.wzkarten.de/pics/Rukm1441.html

Note the T+144 chart - air scource from the Azores!

GEFS ensemble mean also suggesting a similar set-up:

http://91.121.94.83/modeles/gens/run/gens-21-1-144.png?0

Air source from the Med - cold to start with but would soon turn milder if that set-up developed.

ECM will be interesting, but I think a lot of people will have some (much needed) realism injected into them today. It will turn colder yes, but nothing notable or severe.

[carinthian]

UKMO charts have thrown the first doubts about the bitter attack from the east. Upper progs at 144 hours indicate

warmer air could flood back in. However, in my years of obversations, that scenario does not look right. So I am siding with the consistancy being shown by GFS as it now look feasible in the reliable time frame. Who knows what EUROPA comes up with ? BUT we will now have to have agreement in the next 24 hours from the big three if that super cold spell is to evolve!

C

[Iceberg]

Completely agree Paul, I am not saying it will play out like Meto 144 (which is pretty naff for southern areas).

But GFS ENS are also trending in this direction. I.e the southerly undercutting Jet extends to far north with too much power (very El Nino like).

Still 50/50 as to whether this happens atm.

But I would not want to see ECM trending this way as well.

ECM does not follow the Meto at 144z and holds steady, 144 looks like the point where the cold starts to properly take control.

[Eugene]

ECM 00Z is very good and keeps LP much further south of course ECM isn't much good so we should believe UKMO instead right

Seriously UKMO 00Z looks wrong to me, just like ECM looked wrong a few days ago.

[Iceberg]

GFS brings in the chance of a bit of snow for the south come Sat night/sun morning, then a more sidespread chance of sonw come monday night/Tuesday morning onward. This is generally rather sooner than has been progged recently.

[West is Best]

The GEFS ensembles certainly give us reason to be very cautious. There is a lot of scatter at short range, with some much milder members.

By no means is this a done deal. We might yet simply end up with a few cooler days under a high pressure.

Not too worried though about that Azores source. With that much northerly blocking I think it would be the precursor to a prolonged easterly.

The 0z ECM is looking very good to me.

Edited December 9, 2009 by West is Best

[Iceberg]

A very good ECM it delays things a little bit (the real snow potential) until later next week, but the set up is very good indeed. I particularly like the positioning of the southerly undercut later in the run, which allows for a good shaped Greenland high, but thats a bit far away to truely to excited about.

Still interesting weather from this weekend onwards.

A genuine question as I don't have access to the CFS, but did the CFS predict this upcoming set up at all ?.

I can't remember anybody saying anything.

OT but the first Christmas day chart is out by GFS !. and it shows pretty boring weather, maybe snow over the tops of the Scottish mountains.

[carinthian]

UKMO charts have thrown the first doubts about the bitter attack from the east. Upper progs at 144 hours indicate

warmer air could flood back in. However, in my years of obversations, that scenario does not look right. So I am siding with the consistancy being shown by GFS as it now look feasible in the reliable time frame. Who knows what EUROPA comes up with ? BUT we will now have to have agreement in the next 24 hours from the big three if that super cold spell is to evolve!

C

Consistency shown by Euro charts. That looks cold to me and increasingly snowy . So the UKMO looks at odds here this morning at 144 HOURS compared to the other big two. The head guy at Exeter will have to make a decision this morning based on his own-output. The question will be is it or not going to become very cold in the outlook period ?(ie ) from 144 HOURS. I think his/her wordings will be interesting at Mid -day. Knowing what extra information they have at their disposal, a decision will have to be made today before the media get wind from other sources, if you know what I mean.

C

[ChartViewer]

Consistency shown by Euro charts. That looks cold to me and increasingly snowy . So the UKMO looks at odds here this morning at 144 HOURS compared to the other big two. The head guy at Exeter will have to make a decision this morning based on his own-output. The question will be is it or not going to become very cold in the outlook period ?(ie ) from 144 HOURS. I think his/her wordings will be interesting at Mid -day. Knowing what extra information they have at their disposal, a decision will have to be made today before the media get wind from other sources, if you know what I mean.

C

Hi C,

Agreed. Funny how the ECM00Z is a big improvement over last nights, GFS00 is good and now the

UKMO throws a bit of a wobble at T144!!!

Overall good overnight runs from ECM & GFS but still caution needed as UKMO144 bit wobbly.

Regards