Model Output Discussion - 26th December - 1st January

[Frosty.]

I wouldn't read too much into the 16-30 day UKMO outlook, thats generally just repeated until the latest ECM 30 day output at the end of the week. They might change the language slightly but thats still using old data.

Everyone seems to have dismissed the ECM operational run and is happy to go along with the misery fest of the GFS lower resolution outputs..

The GFS 06hrs run was quite similar to the ECM until it reached the lower resolution output, after that not surprisingly it reverted to zonal mild mush.

I think we should just wait and see whether the ECM is on to something.

You make a good point nick, out of interest, was the ecm 12z any good last night as I missed it? looking at the bigger picture I mentioned how the latest meto update almost mirrors the gfs op runs so far today with regard to the 6-15 day portion of the update,

[shedhead]

I wouldn't read too much into the 16-30 day UKMO outlook, thats generally just repeated until the latest ECM 30 day output at the end of the week. They might change the language slightly but thats still using old data.

Everyone seems to have dismissed the ECM operational run and is happy to go along with the misery fest of the GFS lower resolution outputs..

The GFS 06hrs run was quite similar to the ECM until it reached the lower resolution output, after that not surprisingly it reverted to zonal mild mush.

I think we should just wait and see whether the ECM is on to something.

Whilst I wouldn't expect them to do a full update daily, I do think they look at all the available data and as you say Nick change the language slightly, if it needs it. However, if they were as keen on the current strat warming at least offering the chance of a pattern change, I would expect them to at hint at it at some stage in their forecast, but the latest one simply alludes to a very similar pattern to what we saw through the 1st half of December and is in line with what the 06 GFS goes with across the next 16 days. I agree we have to wait and see if ECM is onto something, because without question their latest T+240hr paints a very much more promising picture for cold, but I have to say my confidence in it holding up across the next few runs is low.

Edited December 26, 2011 by shedhead

[Grimsby Snow Lover]

A nice improvement from the NAO and AO models today with a general trend for them both to go negative during the first week of January. I know these are likely to change from day to day but still much more pleasing to the eye than they did through most of December.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif majority look to go negative

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif majority look to go at least neutral with some going negative.

[nick sussex]

You make a good point nick, out of interest, was the ecm 12z any good last night as I missed it? looking at the bigger picture I mentioned how the latest meto update almost mirrors the gfs op runs so far today with regard to the 6-15 day portion of the update,

The ECM still had those pressure rises over the pole but not as strong as todays.

The extended ECM ensembles in terms of main clustering suggest a more nw/se angled jet given that temps over in Holland are averaged in the 6c range, and if you look at the ECM ensemble maps for 168hrs quite a few have the Azores high displaced further to the west.

http://www.weerplaza.nl/15daagseverwachting/default.asp?type=eps_pluim

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/

Some interest in the NOAA preliminary discussions today:

A FLAT AND PROGRESSIVE FLOW PATTERN FROM THE PACIFIC INTO THE

LOWER 48 IS EXPECTED TO BECOME MORE AMPLIFIED AS SHORTWAVE ENERGY

MOVING INTO THE WESTERN US/CANADIAN BORDER FRIDAY DIVES SOUTHEAST

AHEAD OF A BUCKLING TROUGH/RIDGE COUPLET SPANNING UPSTREAM FROM

THE EASTERN PACIFIC INTO THE WEST COAST. GUIDANCE HAS BECOME MORE

AMPLIFIED/SLOWER SINCE THIS TIME YESTERDAY.

Full discussions here:

http://www.hpc.ncep.noaa.gov/preepd/preepd.html

[feb1991blizzard]

I wouldn't read too much into the 16-30 day UKMO outlook, thats generally just repeated until the latest ECM 30 day output at the end of the week. They might change the language slightly but thats still using old data.

Everyone seems to have dismissed the ECM operational run and is happy to go along with the misery fest of the GFS lower resolution outputs..

The GFS 06hrs run was quite similar to the ECM until it reached the lower resolution output, after that not surprisingly it reverted to zonal mild mush.

I think we should just wait and see whether the ECM is on to something.

But i really thought we may have seen something on the last update, i wouldnt expect them to suddenly start mentioning potent easterlies with feet on snow piling up even if the 32 dayer was showing that possiblily because that isnt their style but we really need to at least see them mentioning the possibility of below average temps with PPN above average in the East, if we dont see anything soon then the fat lady will be starting to gargle her throat and Ian Brown will be celebrating his 'even larger teapot' theory.

:( :( :( :(

[Grimsby Snow Lover]

But i really thought we may have seen something on the last update, i wouldnt expect them to suddenly start mentioning potent easterlies with feet on snow piling up even if the 32 dayer was showing that possiblily because that isnt their style but we really need to at least see them mentioning the possibility of below average temps with PPN above average in the East, if we dont see anything soon then the fat lady will be starting to gargle her throat and Ian Brown will be celebrating his 'even larger teapot' theory.

:( :( :( :(

The way I see things Feb1991 is that the met won't change their forecast until their models suggest otherwise. But as the strat warming hasn't really got going any changes in the models won't be clear yet. With the NAO and AO looking more neutral to negative as we head into January I would expect their 32 day forecast to improve regarding menton of cold/snow etc.

Edited December 26, 2011 by Grimsby Snow Lover

[feb1991blizzard]

The way I see things Feb1991 is that the met won't change their forecast until their models suggest otherwise. But as the strat warming hasn't really got going yet the models won't take this fully into account. With the NAO and AO looking more neutral to negative as we head into January I would expect their 32 day forecast to improve regarding menton of cold/snow etc.

But surely a global NWP model will take the strat into account, how far into earths atmosphere gets modelled im not sure but surely it would include the whole of the strat so and surely its output is based on the laws of physics, im not by any stretch saying that a 32 day model is always going to verify but i would think there would be at least some signs.

[Frosty.]

Thanks for the update nick, let's hope for a colder looking Gfs 12z op run and then for some continuity from the ecm tonight, it's not much to ask for is it?

[Grimsby Snow Lover]

But surely a global NWP model will take the strat into account, how far into earths atmosphere gets modelled im not sure but surely it would include the whole of the strat so and surely its output is based on the laws of physics, im not by any stretch saying that a 32 day model is always going to verify but i would think there would be at least some signs.

I can remember that during the February 2009 warming they only changed their forecast when changes looked certain. As the warming is only just beginning I don't believe that any models would be showing any changes that have a high probability of occuring yet. Might be completely wrong though mate.

[feb1991blizzard]

I can remember that during the February 2009 warming they only changed their forecast when changes looked certain. As the warming is only just beginning I don't believe that any models would be showing any changes that have a high probability of occuring yet. Might be completely wrong though mate.

When did the 2009 cold spell start to get modelled and mentioned by the met then?, i dont remember that because that was the spell that got me back into this game, id gave up years before that of ever seeing another pasting and only looked at forecasts now and again, i first knew about that potential on about the thursday or friday before when the media frenzy started.

[Bobby]

Nobody knows what's going to happen 16-30 days out with any reasonable certainty, the Met Office will admit that themselves. I can think of many times the 16-30 forecast has been completely wrong, not critcising MetOffice but you just can't predict far out. It's a somewhat informed guess. Not saying it's going to be wrong but let's not take it as gospel... we don't know, they don't know.

[Cloud 10]

Gusts of 60-70 mph over northern UK looking very likely on wednesday. :excl:

[West is Best]

Another Atlantic conveyor belt 12z, with the same persistent Bartlett high to our south. All very zonal.

So why not sit back and survey all that the west can hurl our way? There is one hell of a storm brewing for tomorrow night / Wednesday. I am very surprised that more severe warnings aren't being issued as this looks potentially very damaging indeed.

[Cecil Hogmanay Melchett]

12ZGFS actually builds a stronger vortex over Greenland than the 6z did.

Really intense vortex is going to take some shifting!!

[cooling climate]

Good post this morning from Grimsby Snow Lover showing

some consistency between the ECM 12z run yesterday and

this mornings 0z run. If the run was to verify we could be

looking at a massive pattern change to much colder weather

for the UK and Europe. It would be nice to see the 12z GFS

run support the ECM. So fingers crossed although I to feel

the ECM may be a little to progressive(hope I'm wrong).

[nick sussex]

12ZGFS actually builds a stronger vortex over Greenland than the 6z did.

Really intense vortex is going to take some shifting!!

The GFS isn't backed by the UKMO, the latter is much more amplified upstream.

http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=144&carte=1021

Compare that to the GFS 12hrs:

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=144&mode=0&carte=1

I'd dismiss the GFS 12hrs operational run especially as the pattern is expected to amplify in the medium term.

[feb1991blizzard]

12ZGFS actually builds a stronger vortex over Greenland than the 6z did.

Really intense vortex is going to take some shifting!!

At least it backs westward towards the end of the run though with some sort of height rise over greeny,

Edited December 26, 2011 by feb1991blizzard

[Cecil Hogmanay Melchett]

At least it backs westward towards the end of the run though with some sort of height rise over greeny,

?

I dont see anything other than zonal and +NAO on GFS.

Its almost asif the gfs is on auto zonal pilot.

[Brum Watcher]

12z GFS not improved, but backtracking, keeping high over the south UK till the end...cannot see changes in the reliable timeframe either.

[weatherguy]

Tasty looking FI being shown on the ECM today, and it's quite stubborn with the general pattern change (formation of an arctic high, and a more amplified upstream pattern) over the last few runs:

Lovely bit of eye candy above to cheer up those feeling a little down from the zonal dross of the GFS...

[karyo]

Tasty looking FI being shown on the ECM today

Lovely bit of eye candy above to cheer up those feeling a little down from the zonal dross of the GFS...

As long it shows the same on the 12z...

Karyo

[Brum Watcher]

ECM on the opposite of GFS, can someone advice me why the models are differing so much in output. ECM seem to be on a pattern change and GFS keeps it the way it is now till the end of the run. is this still a mild outlier??

[shedhead]

The 12 GFS is another ugly run for cold, with a really deep PV and high pressure dominant across Iberia. The pattern is starting to look increasingly well set to me, so we really do need ECM to keep it's long term northern hemispheric evolution on track this evening, because a switch back to a GFS style outlook will be a real kick in the baubles.

Edited December 26, 2011 by shedhead

[Tom Quintavalle]

Yes, Nick

Much more amplification from the UKMO 12z with a much more defined trough pushing south from the Great Lakes.

Lets hope that the ECM 12z shows a similar pattern developing.

Have to say, far too much doom and gloom on here, my calendar tells me its 26th of December today!

Congratulations to Kauto Star and connections, absolutely brilliant! Sorry mods, had to get that in.

Regards,

Tom.

[nick sussex]

Yes, Nick

Much more amplification from the UKMO 12z with a much more defined trough pushing south from the Great Lakes.

Lets hope that the ECM 12z shows a similar pattern developing.

Have to say, far too much doom and gloom on here, my calendar tells me its 26th of December today!

Congratulations to Kauto Star and connections, absolutely brilliant! Sorry mods, had to get that in.

Regards,

Tom.

Given the output out so far this evening the GFS looks the odd one out in terms of its upstream pattern and especially as the UKMO backs the amplified troughing I'd expect the ECM to follow suit.

More importantly is whether the ECM continues to advertise the split PV with those pressure rises over the pole in its later output.