06z model discussion - snowing now and what after?

[Thundery wintry showers]

The 06z London Ensemble has some support for an Easterly commencing around 19th!!

Not a lot of support at the moment, however a couple more runs jumped onboard since todays 00z.

What does everyone think about this and can anyone post a link where I can view other european ensembles?

There is a lot of support for building pressure around Scandinavia between T+120 and T+240, and with a fairly southerly tracking jet there's a chance of the high spreading W to our north if we have a lull in the Atlantic or the lows track further south; thus it is genuinely a possibility.

[BLAST FROM THE PAST]

Huge uncertainty continuing in the short term in any number of areas making longer range outputs of limited value.

One thing looks a good bet - Atlantic lows - but the key aspect would appear to be how far into Germany and beyond these depressions manage to undercut the Scandinavia block. If we continue to see undercutting, this will set up the kind of evolution shown by the GFS 06Z which provides some backing to last night's ECM at the t240 range for height rises from Scandinavia towards southern Greenland:

http://www.wetterzentrale.de/pics/Rtavn2281.html

GP

Ah GP I used your name in vain earlier and it was you who alluded to the undercutting of the Scandi ridge...good thought I got it right. What are your thoughts re the accuweather outlook for the US and its influence on us ie strong southern jet with storm systems coming out from the Carolinas where the two arms of the jet converge.

BFTP

[phil nw.]

There is a lot of support for building pressure around Scandinavia between T+120 and T+240, and with a fairly southerly tracking jet there's a chance of the high spreading W to our north if we have a lull in the Atlantic or the lows track further south; thus it is genuinely a possibility.

Yes indeed TWS.I think there are hints as early as T132hrs. fax.

Also good points made by GP with ECM 500`s and that GFS chart.

Certainly a lot of scope for the models to further change towards the Easterly scenario later next week.

Edited February 9, 2007 by phil n.warks.

[kold weather]

Gp raises a good point here and on the other thread, but the main uncertainty IMO for thre Atlantic is exactly what happens to that low in the Atlantic at 168hrs. Ensembles are in major disagreement because its the EXACT same set-up as yesterday but without the cold pool. some create a split off low that becomes the main depression and this new feature drives ESE like the op run:

http://www.wetterzentrale.de/pics/Rtavn1681.png

However if it remains weak then what will happen is that its circulation will get absorbed into the new develop low which is extremely bad news because it will almost certainly lead toa long SW drag, take a look at the ECM:

http://www.ecmwf.int/products/forecasts/d/...t!chart.gif

Though ECM isn't actually bad in the long term we are starting top run out of time now so things can't set-up too slowly at this point.

Until that low and the energy in the jet stream is solved then ther eis simply no point at lookign beyond hoping for a decent forecast, because this feature is going to make such a huge difference, it could lead us into quite a horrible long term pattern or it could end up being the spark for another noteable cold event and maybe snow event.

In this case the AO could well be totally key in this, the last tanking came from the Pacific region...this time could well go close to us over Russia. IF this feature forms strongly then its game on, because as GP said the jet will HAVE to cut underneath it and that could end with another eent like yesterday but this time with a better ending, just keep an eye on it!

I'll have a bette rlook at everything olater on once the more progressive 12z are out.

But recent trends on the AO side of things and the expected trend into the future may well favor a more southerly jet, as steve said, if it can hpapen once then nothing to stop it happening again, esp if the progs for the Russian high to go bang.

Wildcard time- IF the high over Russia becomes strong enough then it'll send a major flusgh of cold air southwards along its eastern flank and watch the jet buckle, even if ther eis a bartlett set-up the high will get absorbed into the bigger high, 1991 all over again!

But that really is all or nothing.

By the way, the only year to see as fast a collapse in the El nino was 83, 97-98 el nino did so but not for another couple of months into the year, Feb 83 ende dwith a CEt of 1.7C after a very mild Jan (6.7C)

Edited February 9, 2007 by kold weather

[Paul]

Locking this one as now, new thread has been started for the 12z :lol:

[johnholmes]

for a short term idea by me of where snow may occur today pse go to in depth model discussion.