Model Output Discussion - 1st - 7th January

[Cloud 10]

the ecm ens mean charts are a mess tonight as there are obviously plenty of clusters which makes the mean pretty 'mean'ingless !! the spread on uppers by day 10 and also heights across the NH are as wide as i can ever recall. maybe a good time to stick with the op ??? anyway, across the NH there are three clusters at T240. one is the aleutian ridge, one is a se greeny ridge stretching se towards the uk and the third is a north sea ridge stretching back to eastern scandi. all in all, three decent clusters in a sea of uncertainty.

op and control in perfect harmony !!

LOL!,carnage in the northern hemisphere.

Meanwhile the short range ecm ensembles are out.

BOOM!

[chionomaniac]

I was looking through the ncep charts from mid to late jan 2009 yesterday with this in mind. The gfs runs from around the 21/22 are spookily similar in suddenly changing to create trough disruption mid Atlantic and driving the ridge north. Chio, what date was the SSW that month?

Late January

[kold weather]

Certainly a trend cooler on the 12z ECM ensemblwes, thoughh few go to the extreme of the ECm op run which is very interesting run.

I think these models though are far closer to what I've been expecting the models to suggest with regards to the Arctic, the idea that the PV was going to re-organise and strengthen loads under several increasingly strong warming events always was going to be a stretch.

Certainly a few hints things are changing, my gut is the current 12z suite are too agressive with bringing in an easterly attempt, and instead we'll end up seeing some cold zonality, but awith ever increasing chances of northerlies and eventually easterlies as the jet dives south.

Things looking up, nearly bang on what GP said...

PS, as others said, operartional runs lead the way with easterlies...normally...

[mulzy]

Nick - I think the masses in here will feel more comfortable if that mean line moves nearer the operational line

Edited January 7, 2012 by mulzy

[SMU]

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

I know they have been posted- but exactly as expected- &

yes thats a max of -2 at Day 9- so that would probably bring us close to an ice day here in the SE as the flow is ever so slightly SE- meaning a short hop over water to modify the air!

S

Also anyone mentioning about continetal warmth currently = warm easterly think again-

The Arctic high is on the cold side of the jet-

S

Edited January 7, 2012 by Steve Murr

[weatherguy]

The jet will not travel east to west,(although that would make things interesting!) but if the zonal mean winds do reverse,then this encourages high pressure in the arctic which in turn forces the jet to move south,which greatly increases the chances of cold weather effecting us,or other countries at similar latitudes.

I'll refer you to chionomaniac's excellent first post in the stratosphere thread which explains

it slightly better. :lol:

http://forum.netweat...ost__p__2148930

Ah okay thanks, appreciate it

I'm still learning... :blush:

[stormchaser1]

Evening everyone, just to let you all know im back !

[stewfox]

I really don't understand why your basing this on current temps. If the orientation of the HP is backing the cold W then current temps have no significance. Look at the charts below and note and how quickly the cold airmass moves S.

http://www.wetterzen...s/Rtavn1442.png

http://www.wetterzen...s/Rtavn2402.png

The main issue isn't the current temps across Europe but whether we can get the cold airmass to hit the UK. If it did then due to how this synoptically develops then upper temps as low as -15C would be possible.

I have seen this mention a number of times, ie no cold in Europe or to the North East so it would take 'time' for cold to evolve/arrive.

We live on a land mass not sea mass, so if cold comes our way it will come our way, emended cold maybe harder to shift but thats different

The reason you can see a 52f drop in temperature from the 11th to 14th Jan in Whitehorse

http://www.theweathernetwork.com/fourteenday/cayt0019/table?ref=tabs_14day_table

is caused by this

http://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=1&archive=0

[peterf]

just in time lol.

[kold weather]

http://www.knmi.nl/e...M_06260_NWT.png

Also anyone mentioning about continetal warmth currently = warm easterly think again-

The Arctic high is on the cold side of the jet-

S

Pull in the right sort of easterly and the air will cool down ultra fast over Europe, especially if you can any sort of under-cuttinmg upper trough into Europe.

Some stonking GFS ensembles tonight as well, P8 is nearly perfect evolution!

Or if you like the long game, P3 is pretty great as well...

[bluearmy]

http://www.knmi.nl/e...M_06260_NWT.png

I know they have been posted- but exactly as expected- &

yes thats a max of -2 at Day 9- so that would probably bring us close to an ice day here in the SE as the flow is ever so slightly SE- meaning a short hop over water to modify the air!

S

Also anyone mentioning about continetal warmth currently = warm easterly think again-

The Arctic high is on the cold side of the jet-

S

dont need to guess today steve

http://www.ecmwf.int/samples/d/banner/page.html

[nick sussex]

Unfortunately we don't have the benefit of the NOAA extended discussions this evening as its the weekend and their maps are normally computer generated on Sat and Sundays.

The only thing I managed to find regarding the all important progression of those troughs is this link for day 7, this is put together by a forecaster and takes into account the main models.

As Steve mentioned earlier the slower these troughs exit the USA the better:

http://www.hpc.ncep.noaa.gov/medr/day7nav_bw.html

Unfortunately we don't get to see Europe here but this looks to centre the low in NE Canada.

[Cloud 10]

Ah okay thanks, appreciate it

I'm still learning... :blush:

Join the club,its quite a big one!

Evening everyone, just to let you all know im back !

Blimey! its lord lucan.

[bluearmy]

The ECM ensemble maps are in:

http://www.ecmwf.int...t!2009112700!!/

The control run supports the operational, however there are varied solutions there with some bringing low pressure se towards the UK, if we don't get this Scandi block then at least the next best option is to get the jet tilted nw/se, to at least initially drive some energy into Europe and displace the high to the south.

The ECM short ensembles:

http://www.knmi.nl/e...M_06260_NWT.png

The operational has limited support but the cluster towards the end still shows a drop.

Bear in mind that its normally operational runs that lead the way with easterlies and not the other way round.

remarkable that looking back to the 00z run, you'd struggle to find many members where you could make a case for the T168 op and control charts that followed on the 12z run.

[kold weather]

Right, I've made a new thread here, so post the 18z run data and stuff in here:

This thread will be closed shortly.

[sebastiaan1973]

Late January

24th of January 2009

[nick sussex]

remarkable that looking back to the 00z run, you'd struggle to find many members where you could make a case for the T168 op and control charts that followed on the 12z run.

Theres certainly been a big switch in 12 hours, even some of those that don't suggest a quick easterly at least tilt the jet more favourably.

Whatever the pub run shows its hard to have too much confidence, if they've just picked up on this signal could be an over reaction, but more interestingly if they've been a bit slow then the trend might accelerate tomorrow!