Model Output Discussion

[SMU]

So i take it you have now backtracked now steve from your post a few days back when the ecm was not on board you saying we will probably end up with the watered down version off this set up? I agree with you nothing wrong with this at all but everybody is kicking off here about it could potentially be better than 1991 wouldn't that be something!!! Anyway just watched rob on the bbc and he does like a ramp he says don't worry about the cold that is not going to happen until later next week and then had a little evil giggle i think he knows that we are about to see something special.

I Dont recall a post of that type?-

I nailed my flag to the mast on a Strong Easterly---- Which appeared on the 06Z nogaps chart at 144- ( IIRC 2 days ago APPROX)

ECM has performed poorly of late ( again I recall commenting on that yesterday after the 12z run) - its currently third behind the canadian & GFS (X) although thats at NH level-

FWIW- this is where I am-

I dont think we will surpass 1991's glory totals as I vividly remember 12inches on my mums dustbin--- this was reached from continual snow showers over 5 days-

I think If the pattern holds theres a good 24 hour window ( poss longer if the southern arm of the jet is slightly stronger ) for a PERFECT convective snow set up-

lets clarify quickly thats *

Sub -10C 850 temps, Continental feed, VERY low heights- circa 500 DAM & a flow over the North sea-

IF all that varifies that 24 hours can deliver in the region of 12 inches of snow- possibly more- however the coverage in terms of the UK is likely to less & confined to PROBABLY one of these counties-

Kent, Suffolk, norfolk, lins, yorks , borders-

anyway on with the 18z......

I personally think the trough will be placed slightly further east than the 12z runs-

S

S

Edited December 11, 2009 by Steve Murr

[Nick L]

18z coming out now, just spent 4 hours rebooting 2 computers back to factory settings so i missed the ECM discussion etc, is the ECM any good? and does it agree with the latest 12z UKMO and GFS.

Would greatly appreciate your replies as i'm very busy.

Thanks

Lewis

The ECM is stunning, absolutely stunning.

http://212.100.247.145/ecmimages/20091211/12/ecm500.120.png

http://212.100.247.145/ecmimages/20091211/12/ecm500.144.png

Goes completely mental at the end:

http://212.100.247.145/ecmimages/20091211/12/ecm500.216.png

[Duncan McAlister]

http://www.wetterzentrale.de/pics/archive/ra/1962/Rrea00119621231.gif

http://www.wetterzentrale.de/pics/archive/ra/1962/Rrea00219621231.gif

As you know these charts brought very heavy snow to most parts of england yet the uppers were only around -7hpa. Now look at our charts:

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

http://www.wetterzentrale.de/pics/Rtavn1441.png

Absolutly no difference to start of 1962/63 winter and now, very very promising signs!

But obviously what made that winter special, there was just never really a proper breakdown, something that may not be acheved again for another 300 years.

i really think we could be on to something special here but dont want to tempt fate lol.

I'm glad someone else has pointed this out! Very low uppers are extremely rare over Britain (Jan 1987 is one such occasion), most of our cold spells have been between -7 and -10 it would be fair to say? The record low temperature in December 1995 was achieved with snow cover, slack pressure and uppers of -8C. This is all we need for very low temperatures

[weather eater]

Anyway just watched rob on the bbc and he does like a ramp he says don't worry about the cold that is not going to happen until later next week and then had a little evil giggle i think he knows that we are about to see something special.

And a little tease about the showers effecting the SE on Sunday night still being of rain, he really should do every forecast. With the 18z now rolling out I don’t expect any nasty surprises, but I will be interested to see how it handles the midterm.

[Lewis]

The ECM is stunning, absolutely stunning.

http://212.100.247.145/ecmimages/20091211/12/ecm500.120.png

http://212.100.247.145/ecmimages/20091211/12/ecm500.144.png

Goes completely mental at the end:

http://212.100.247.145/ecmimages/20091211/12/ecm500.216.png

WOW what a moment, what a run!

Thanks nick

[snowfart]

18z looks good! but looks like a warmer air will try to break through around 25th )):

[PB22]

Extended ECM ensembles for De Bilt:

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

Quite good agreement on a prolonged spell of cold weather over the water...

[Nick L]

18z looks good! but looks like a warmer air will try to break through around 25th )):

18z is only out to +48 so far. You must be looking at something completely different.

[Snow Queen one]

18z looks good! but looks like a warmer air will try to break through around 25th )):

How do you know that it is not out fully yet on wetter or NWExtra?

[Altostratus]

Out to T+48 and already there are some very minor changes. The block seems to be slightly further to the north west. We could do with a decent run just to settle the nerves and help us get a good night sleep

[bluearmy]

Bluearmy good post but you hav e just answered your own post.....

1. We are NOT in a late Winter synoptic situation

2. We will not hve a Mild continent

3. The pattern is setting up as those of yesteryear?

4. I sit not better to se this now and also to hear of a warming event that may come to fruition

in Mid Jan?

Regards

dont disagree with any of that CV - just pointing out to some posters that its not that long since we had dream sypnotics. can i also bring to the attention of all the ecm bashers that todays NOAA and cpc discussions both comment that ecm output from yesterday turned out to be more reliable than GFS upstream. not in our part of the NH though and as ever, they refer to the mean rather than the op. the problem we have is that we dont get to see the ecm mean.

[Ben_Cambs]

18z looks good! but looks like a warmer air will try to break through around 25th )):

That may of been from the 12z run, the 18z run update has currently only got to T+66! So an upgrade is possible

[SMU]

Out to T+48 and already there are some very minor changes. The block seems to be slightly further to the north west. We could do with a decent run just to settle the nerves and help us get a good night sleep

Looking at the jet profile at T72 & comparing it against the 12z T 78 then I would say the angle of the jet IE Returning west through the North sea is less acute- I would expect to see the trough moving LESS SW & more South-

Just to clarify I expect the trough to end up further S&E come varification time-

( The trough Axis will be less pronounced towards the west)

S

Edited December 11, 2009 by Steve Murr

[snowfart]

Oww.... As you can see I am a newb I got it from

http://theweatheroutlook.com/twodata/gfs/18_348_mslp850.png

[patrickshere]

That may of been from the 12z run, the 18z run update has currently only got to T+66! So an upgrade is possible

Out to +84 on meteociel.

[Cloud 10]

here is your ECM 12z chart from the Archives-

This chart preceeded a negative CET Month.......

S

Blimey,you certainly nailed that one.!

[cold snap]

Remember its one frame at a time when viewing the model update unless you want to wait till they have completly finished.

[Interitus]

away from the far NW coast then this is fully snow event-

the area most at prone for snow turning to sleet & rain is the 850- 1000mb level-

With a continental surface feed over the uk then this layer ( otherwise known as the boundry layer) will be well & truly entrenched with cold surface air- so the column from cloud to surface will have bitterly cold polar uppers, slightly warmer air mixed in - this would ride OVER the Cold air -& not mix it out straight away-

( The air will have a high DALR ratio ) - very typical of an artic plunge-

its a MAINLAND snow event.... irrelevent as its at 240

S

http://www.wetterzentrale.de/archive/ra/1979/Rrea00119790125.gif

here is your ECM 12z chart from the Archives-

This chart preceeded a negative CET Month.......

S

The continental air would not be entrenched at low levels at 240h because it is already being shifted from 168h onwards.

[bluearmy]

Looking at the jet profile at T72 & comparing it against the 12z T 78 then I would say the angle of the jet IE Returning west through the North sea is less acute- I would expect to see the trough moving LESS SW & more South-

Just to clarify I expect the trough to end up further S&E come varification time-

( The trough Axis will be less pronounced towards the west)

http://www.meteociel.fr/modeles/ukmo2.php?ech=96&carte=2000

the T96 FAX has a better flow than the equivalent last night - ne-sw (upgrade). the 528dam is shown running through the centre of the depression. the T120 will show us more and it not worth any more comment until thats out.

[Duncan McAlister]

These synoptics are just sheer poetry, with that big yellow circle to our NW and the Greenland High linked to Scandinavia

[Lewis]

This is how we do We make a move and act a fool when we see the pubbbb runnn :winky:

Lovely 18z on the way and this time its heading direct into the central part of N england "the backbone shall we say "

Ramp mode now

Edited December 11, 2009 by Storm Force Lewis

[Fozfoster]

DAM line looking better at 114

[patrickshere]

Christ, what a run this is turning out to be.. I don't even care what's off in FI.

[Thundery wintry showers]

GFS 18Z potentially colder/snowier earlier on as the shortwave doesn't hang about for as long in the south- 17th December should be progged as something of a winter wonderland in the eastern side of Britain (including east Scotland all the way down to the SE). I still preach some caution about the possibility that it might not turn out as snowy as suggested by the GFS 18Z.

[Harsh Climate]

Much better greeny high with yellow covering most of greenland now, super! I think the easterly on wed/thu might last longer on this run as a result

Actually at 136h this run is looking like a slight downgrade for scotland/northern england in terms of that easterly and on the flip side an upgrade for the midlands.

Lets hope in future runs it doesnt go further south into france eek

Edited December 11, 2009 by Jed Bickerdike