Model Output Discussion 12z 07/11/2012

[SMU]

ECM 168

http://www.meteociel.fr/modeles/ecmwf/runs/2012111112/ECH1-168.GIF?11-0

Looking as good as its had for a while

S

[cold snap]

bit better steve ,kind of caught in two minds.no mans land i was hoping for a little better.neither cold or mild at 168

[nick sussex]

ecm at 144 slight improvement look at the angle of the vortex.ecm at 168 might be better we shall see

ahh nick got there before me

Unfortunately still too much energy running over the top, but its a positive that we see some energy going into the southern arm of the jet.

If that northern arm could relent a little then it would help matters, still we'll have to see whether any future outputs build on that.

[IDO]

how is 13-14c very mild for November, its very common for it to be 14c in november its not january now is it, the charts look pretty awful to me and i can't see any optimism right now, we can talk about all these "supposed good signals" all we like and that the vortex might split in FI, but the fact is euro high trash is staring us in the face yet again, its just like last year, and until i see good charts in the reliable time frame then i won't be getting my hopes up

I think we should stop using "mild" to sum up temps as it appear to be subjective to some. However it is apparent that next week temps will be "mild", and courtesy of "Steam Fog" from the Two site:

http://i305.photobucket.com/albums/nn216/simonneil/NewPicture1-7.png

From the 13th till 23rd the average daily anomaly is +1.9c with a +3.5c and a +4.2c in there.

I for one am looking forward to a milder interlude before Winter moves in.

As for the latest GFS and GEFS, there is, on face value, little sign of a wintry spell, and zonal remains the watchword (normal caveats apply). The mean (850s) for the ensembles does drop from 7c to -2 from T144 to the end of FI so a cooling trend but ending with average fare for late November:

http://cdn.nwstatic.co.uk/ensimages/ens.20121111/12/t850London.png

I still want to see some decent FI runs as we head into late November, as the synoptics do not look good for mid-December onwards, as far as recent stratospheric cooling is concerned. I tried to find an ensemble member who had some cold uppers over the UK at T384, but couldn't find one:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=5&ech=384

So It does look likely that an early start to Winter will no longer happen in November and its December's outlook we now have to focus on.

[shotski]

ECM 168

http://www.meteociel...H1-168.GIF?11-0

Looking as good as its had for a while

S

Hi Steve, looking back in the archives a very similar pattern developed mid November 2010 with a scandi high retrogressing to Iceland.

Edited November 11, 2012 by shotski

[Ian Brown]

Meteociel is the French site that this comes out on ? Sorry I'm not long back from the US.

I would look at that ECM chart and the thing you have is that pressure is high to the West and East of the vortex to the North, so it is not going to evolve into displacing the cold air to the middle...

[Ice BIast]

Not a bad chart, heights trying to build north and a good angle on the jet

Edited November 11, 2012 by lce Blast

[nick sussex]

Redemption possibly here comes the negatively tilted troughing!

The 192hrs chart isn't too far from what the BOM cannon fodder model showed this morning, its essential we get this negative tilt to help ridging extend nw.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2012111112/ECH1-192.GIF?11-0

Looking good- watch pressure fill to the NW on the 216 & 240-

S

[ukpaul]

I think we should stop using "mild" to sum up temps as it appear to be subjective to some.

It also depends on where you are, temperatures for the South East are pretty much progged to be average and above so for maybe a day or so.

People shouldn't be upset with average conditions, I know it's not very exciting but if anyone thinks they are going to be able to walk around in shirt sleeves then they are going to be sadly disappointed (or from Newcastle, in which case, 12 below would still mean no need of a coat for a night out!)

[Frosty.]

Hi Steve, looking back in the archives a very similar pattern developed mid November 2010 with a scandi high retrogressing to Iceland.

If only we had a time machine that could take us back to late november 2010, it would be EPIC if we could break the shackles on the upcoming pattern into something even faintly resembling that amazing period.

[Alan Medlock Valley]

that is the sad fact anyone who talks the brutal honest truth gets called a troll

im only a novice but its blatant to see the charts are rubbish in the reliable timeframe we can talk about the NH profile as much as we like, but our island is in bog standard mild conditions, anyway the ECM is coming out now and if its good i will cheer up lol

Indeed and it is more difficult for us to get cold here due to where we are positioned in Europe, a few things moderate the cold here. If we lived 800 miles east or north it would be the opposite difficulty! Take somewhere like Warsaw, Moscow and Helsinki as examples. But As of tonight I remain optimistic about the current models, as we all know things can change swiftly.

[cold snap]

tell you what out of know when ecm at 216 decides to adjust things 240 could be special ,very special infact

[Bristawl Si]

Cant believe what i'm reading on here tonight - suddenly there's hope for the coldies for later in november. In the last few days many were writing off November, incl some of the more 'respected' and allegedly knowledgeable ones!

Fair play to Steve Murr for sticking to his guns - again!

[SMU]

http://www.meteociel...H1-240.GIF?11-0

ECM day 10 paints the picture of why I posted this morning ( the BOM) & why the ensembles + day 10 for De bilt have been dropping off-

*IF* the pony F.F.S model, had depicted something like the above for day 10 then all the people following only one model ( & THE WRONG MODEL) for pressure modelling over scandi would have different thoughts-

Just for the pedants - not mega cold as the surface for us- but rapidly cooling off day 11 + 12

day 10 sees snow moving over Germany etc- showing how fast things can change....

S

Edited November 11, 2012 by Steve Murr

[bluearmy]

ECM is simply generating a run out of the recent gefs suites but a few days early. This is down to the strength of the blocking to our east. Right or wrong! No idea but this op run is fairly in tune with the ens 00z run from ECM this morning. I would suggest we have two problems here - the first is the energy in that ex tropical wave approaching us at day 6 and the second is modelling a block to our east. Expect more chopping and changing.

[AWD]

I think the one thing we can take out of tonight's varying model output is a great deal of uncertainty as to where we go after this coming week.

The GFS & ECM are markedly & obviously different at day 10.

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=1&type=0&archive=0

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0&carte=1

I'm not going to pretend I know which one, if indeed any are correct and which one, if indeed any I think will verify, I will leave that to the more knowledgable.

What I think though, is writing off a large length of time in respect of the UK weather is risky.

Looks to me as if the ECM Det is following its sister model, the EC 32 Dayer ( based on reports from people who have access to it ).

Interesting times ahead.

Edited November 11, 2012 by AWD

[SMU]

Just one thing to add -

Remember how the GFS was used at 228 the other week to depict what would happen- & actually how well it varified-

You could almost pitch the same certainty that a pattern developing from the East will be modelled on that higher level through the ECM & UKMO against the GFS....

S

[Snowy Easterlies]

ECM looks good from a NH perspective, in terms of scandi blocking, but it doesn't really deliver anything for us does it, unless of course things develop down the line ?

[nick sussex]

The ECM at 240hrs is the best output of the season so far in terms of wintry potential.

I'd gladly take that if offered as that trough disrupts further you'd see more energy transferred into Iberia with the ridge backing west.

Unfortunately its at 240hrs so has a very low probability of verifying.

There are some key things though to watch in future outputs and these are within 144hrs.

The starting position of any ridging to the east in a nutshell the further north and west has big effects later, also that low heading out of the eastern USA the further south this is at interacts with the main troughing, and finally tilt of troughing.

For newbies this means the orientation is nw/se this helps to develop the ridge to the east by means of WAA warm air advection, the key thing is to get enough energy heading se into Iberia and the Med as this happens pressure fills out to the north and nw.

This may well be a false dawn and just a crumb by the ECM to keep us interested but given the current stratosphere profile I can't see any route to cold at least initially unless it comes from the east, after that things may look different.

[blizzard81]

Redemption possibly here comes the negatively tilted troughing!

The 192hrs chart isn't too far from what the BOM cannon fodder model showed this morning, its essential we get this negative tilt to help ridging extend nw.

Great to see you posting on here again Nick. I always look forward to your balanced and very informative posts. Unless my memory

is deceiving me, I seem to recall the BOM doing extremely well at predicting the cold period of late Nov/early Dec 2010 and also maybe

the cold spells of 2009/10. It seemed to model Scandi highs with a very high degree of accuracy, just like the ECM. The GFS on the

other hand seems to struggle with the modelling of scandi highs but is very good at picking up Greenland blocking.

Edited November 11, 2012 by blizzard81

[ukpaul]

Scotland's going to get soaked if that nasty little low zips through next Sunday/Monday as progged by GFS. ECM takes it further south but without as much energy. There's already a warning out for South West Scotland for Tuesday and Wednesday by the way. Something to keep an eye on.

Edited November 11, 2012 by ukpaul

[lorenzo]

The GEM 00z run from earlier today ended in a similar place to the ECM, maybe one to watch out for..

[blizzard81]

All eyes now on the ECM 12z ensembles. We will be able to see how much support there is for the operational.

[nick sussex]

Great to see you posting on here again Nick. I always look forward to your balanced and very informative posts. Unless my memory

is deceiving me, I seem to recall the BOM doing extremely well at predicting the cold period of late Nov/early Dec 2010 and also maybe

the cold spells of 2009/10. It seemed to model Scandi highs with a very high degree of accuracy, just like the ECM. The GFS on the

other hand seems to struggle with thee the modelling of scandi highs but is very good at picking up Greenland blocking.

Thanks I've come out of hibernation !

In terms of the BOM although its based on the UKMO model it has a lower resolution so best take that into account.

I should add a note of caution to the ECM, to get to 240hrs you need a good starting position within 144hrs re how it holds troughing further west with less energy into Scandi.

The UKMO isn't as good although much better than the GFS, we'll have to see whether those pull the pattern further west tomorrow.