Model Output Discussion

[snowmadchrisuk]

relief 18Z not followed ECMWF, very cold but dry easterly for monday, only snow in se, monday is still FI though as clearly seen with the uncertainty, very nervy look in morning, ECM 00Z key

Dry ?????? that Chart looks like a bit more than just the SE to me.

Edited December 10, 2009 by snowmadchrisuk

[bluearmy]

Not flawed- just wrong in this incidence..... ( for reasons highlighted above )

Looking at t108 I think this is going to be a peach for the SE...... because the shortwave is coming just slightly further west from the 12z-

S

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=114&code=0&mode=5&carte=1

with a favourable jet profile from the north.

re ecm 12z run. maybe there was a problem - who knows? the fact that NOAA comment on it and use it in their discussion would lead me to doubt that there were any issues. however, the cpc charts are so at odds with it in their 'human input' that i cant conceive that it can be right to put energy back into the northern arm at that time and collapse the greenland block.

[Altostratus]

What a chart!

http://www.wetterzentrale.de/pics/Rtavn1381.png

[Duncan McAlister]

Looks like some good cold heading Scotland's way judging by the tightness and direction of the isobars....

[clark3r]

Mass relief as the GFS sticks to its guns, if anything upgrading the cold early on. So will it be the ECM that is forced to backtrack tomorrow am? The plot thickens!

Very good run this so far and the cold is so very close to the reliable. I could see snow showers across much of the SE and East Anglia on Monday. Lincs would also be affected. Not sure how far inland the showers would track, but it'd be interesting to find out.

what do you reckon for the latter stages of next week do you think will have the chance of that very cold shot of air coming from the northeast??????

[kold weather]

As Steve said this run would be an utter peach for the SE, I think our locations would get a very good snowfall in that set-up.

Anyway a very good 18z run, in no way even a hint of a backtrack and we are now getting very close to the timeframe in question. 60-72hrs is where the differences start, going to be very interesting to see how this all evolves, I esp interesting in the paralell given how consistant its been.

[Duane S.]

Jeeeez, I'd forgotten quite how fraught it gets in here when we start getting close to the 'reliable timeframe'. Some of the posts I have had to trawl through here are an absolute joke and quite pathetic TBH. Try to be objective. Listen to what the few experienced forecasters and experts on here have to say. Listen to them, don't take each run as gospel. One chart which I WOULD say is fairly important is the FAX later on but let's get it into perspective, it won't be ALL OVER' even if that is a downgrade! Ah what's the use... :lol:

As for the 18z, looks good to me, certainly seen enough up to +102 to say it is not keen so far on an ECM evolution. ECM just looks flawed, as it did on last night's 00z. It won't happen like it tells it.

Sorry I have to say this bit but really, Ian Brown, your outrageous comment earlier (you know which one), for somebody who predicted the warmest December CET on record and mild SWerlies all month, I would think you may wish to be a little less condencending in your posts and a little more humble, no?

[swfc]

The stage from next wednesday is the biggy for me on the GFS run, the first cold shot barely delivers, need to see that LP rush down from the NE, between the two cold shots 0C uppers approach from the north before the real cold air can get to us. East coast marginal for monday/tuesday I feel.

Evening.P[hew.So can someone explain whats happened to ecm please.It seems a thousand miles away from every other chart and after missing the output all day im slightly confused.Thanks in advance. :lol:

[Southern Storm]

with -10 uppers over the relatively warm channel, can we expect to see a lot more convection?

[smich]

I think we need to recognise here, that we are not the people that designed these models, or operate them. We do not have that inside knowledge.

As such, we should not really be commenting on anything "inherently" wrong with them.

Just how they verify.

smich

[Paul Sherman]

Solid GFS Tonight and as others have said first real shot of cold into the South East with Wintry Showers turning incresingly to snow overnight Sunday into Monday which could leave a covering anywhere from Kent upto East Yorks, then much more interesting from Monday evening into Tuesday when the winds tilt just so ever East-North-East, would expect streaming showers from that, a little lull on Wednesday then all I can see is more Snow Chances for the whole country from Thursday onwards if the run goes the way it is looking.

Paul S

[cyclonic happiness]

This beauty would bring blizzards in from the North Sea!!!!

[SNOW-MAN2006]

Come on ya weee beastie gets those -10's in :lol:

http://209.197.11.171/c9s4a5k3/cds/gfsimages/gfs.20091210/18/159/h850t850eu.png?dopvhost=charts.netweather.tv&doppl=0bb062674091148c40c114dc91041f9740c114f8&dopsig=8fe3ca2ac79128c3f198891e501ce8d3

[swfc]

Quick one,has ecm missing data and if not why does gfs look so good. :lol:

[Tom D]

This run is a stunner! A massive improvement over the 12z!

Trust the pub run to come up with such an upgrade however... :lol:

This chart shows a great easterly and it could be backed up with a northerly a bit further on with that Scandi low.

[Frosty.]

Tonight's 18z is completely in line with the meto update today, with an increasingly wintry spell developing, especially from thurs/fri onwards, fingers crossed the models are still showing this in the morning.

[TEITS]

Some might be thinging "this is the pub run" however what your seeing from the 18Z so far is actually representative of the GEFS mean and the GFS parallel runs these past few days.

The charts around +162 are suggesting a wash streamer. :lol:

[kold weather]

Yep, by 156hrs the east coast gets hammered, looks like mainly a more northern event then the intial cold shot that whilst snowy further north would be even more so in the south.

as for the ECM data issues, where is the link that says that, it all depends on exactly where the data is missing and stuff like that. I wouldn't get too excited about this however, the ECM tends to be very stubborn at this range but the GFS really isn't giving ground and neither is the UKMO.

The UKMO is the key model if both them stay with thier respective ideas on thier 0z runs.

[Cecil Hogmanay Melchett]

And by thur TEITS gets a direct hit! :lol:

On the other hand are being setup by gfs for the big fall come morning?

FAX charts VITAL tonight,who do the pro's go with ?

UKMO AND GFs

OR

ECM

120H FAX will tell us a LOT.

And save me getting too fed up in the morning if they look like ecm solution.

18z brings the beast from the east----

[Neilsouth]

Interesting jet pattern:

http://91.121.94.83/...nh-5-150.png?18

The jetstreak over Scandi is better aligned to pull the colder air towards us.

Edited December 10, 2009 by shuggee

[wysiwyg]

Quick one,has ecm missing data and if not why does gfs look so good. :lol:

Read back a little bit swcf - for my money there's reasonable consensus that the ECM run tonight may well have been affected by missing data

[Iceberg]

And the fantastic thing is that it's set to repeat again after 180Z !

Anyway the reliable timeframe out the way (upto 144Z).

No backtrack

Still the Diving SW that was shown on the METO.

Mon/Tues could hold a surprise for certain areas in the SW as far west as the IofW and for Lincolnshire, maybe a few cm's in these places, not bad for a pre starter.

[Big Innes Madori]

Looks like some good cold heading Scotland's way judging by the tightness and direction of the isobars....

Ah, Thanks Duncan!

At last a post regarding what he models might be showing for somewhere else other than the South East

Big Innes

[abruzzi spur]

Reading this topic is an extraordinary experience, particularly at times like this. I have only a limited ability to read the models so look to this topic for guidance, and tonight I appear to have been told the following:

1. big freeze still on

2. big freeze might be on

3. big freeze not as big as first thought but still quite big

4. big freeze now "downgraded" to "even larger teapot big freeze", ie not much of a freeze at all

5. cold snap

6. cold snap-ette

7. cold up north but not down south

8. cold down south but not up north

9. ECWMF is the most reliable model

10. ECMWF model is not to be trusted tonight

11. ECMWF is not be trusted in this set up, whether tonight or not

12. GFS is not to be trusted in blocking set ups

13. GFS has been consistent and therefore is to be trusted (nothwithstanding 12)

14. It will get cold shortly

15. ECMWF data is missing tonight according to our new friend from Holland

16. Our new friend from Holland is clearly on the money (although we are all asking each other whether we know if he/she is right or not)

Is it any wonder we are probably all a little frazzled.....

When I was at secondary school second year in 1978 I used to sell weather forecasts to my class mates for 5p. I based them on a presusre chart in the daily paper and by looking out of the window of the science lab towards the West. Surprisingly I had a few sales. Most often I was roughly right but living then near the Severn estuary it was pretty reliable to say it was about to rain. My approach would have been useless in this current scenario so please let's have some measured and considered views (that I can nick and sell on at 2009 prices). Thanks.

AS

[NorthantsSnow]

what do you reckon for the latter stages of next week do you think will have the chance of that very cold shot of air coming from the northeast??????

The potential is there, absolutely. And the 18z buys into it completely with upper temps of -12 into the UK by next Thursday.

http://212.100.247.145/viewimage.pbx?type=gfs;date=20091210;time=18;ext=168;file=tmp850;sess=23496a6ee58e5809dbf860652015972c;

Looks like I'm going to have to get up half an hour early tomorrow so I can check the models before work.