Model Output Discussion - The Run In To Christmas

[Summer Sun]

ECM ens looking good post Christmas

 

 

Nothing mild what so ever from ECM from Christmas eve onwards

 

[Cloud 10]

Day 10 ECM ensemble mean is virtually a carbon copy of the 00z. :smiliz64:

 

 

 

 

[texel]

Dummies out dummies in every time. Give it time for gods sake.

Edited December 18, 2014 by Polar Maritime
To delete pathetic remark.

[bluearmy]

mean, spread and anomoly

 

                                  

 

 

mean is great for cold

 

spread shows a big cluster of runs sink the high close to ireland

 

anomoly is great for cold

 

of course, it doesnt mean that the last two gfs suites didnt happen nor the ecm op but it does mean that in general, not a lot has changed. the envelope remains reasonably broad but the cold solution is still the favoured one. (and potentially v wintry judging by the anomolys)

[bluearmy]

Day 10 ECM ensemble mean is virtually a carbon copy of the 00z. :smiliz64:

 

EDH101-240.gif

 

i noted this on the cpc chart a couple days ago but that ens anomoly is beginning to look a lot like the lrf's .................  (it also means it looks like cpc D+11 gfs superens from two days ago which is notable for consistency)

[Captain Shortwave]

mean, spread and anomoly

 

EDM1-240.gif                 EEM1-240.gif                  EDM101-240.gif

 

 

mean is great for cold

 

spread shows a big cluster of runs sink the high close to ireland

 

anomoly is great for cold

 

of course, it doesnt mean that the last two gfs suites didnt happen nor the ecm op but it does mean that in general, not a lot has changed. the envelope remains reasonably broad but the cold solution is still the favoured one. (and potentially v wintry judging by the anomolys)

Certainly happy with that, it might topple but a solid 3-5 days at least where snow could fall almost anywhere given that disturbances could develop and run south through the country. Lets hope it sticks and the other models back it.  :w00t:

[ANYWEATHER]

dummies out dummies in every time. Give it time for gods sake.

Well ,A great explanation on tonights models :w00t:

Edited December 18, 2014 by Polar Maritime
To edit quoted post.

[tinybill]

all i say  DEC  30 looks interesting  low of 970  over  ireland

[Jason M]

Having just looked through the GEFS I actually think they are pretty good. Not quite as good as the 06z set but the difference really is just within the margins of natural variability. Peeps should really just view the opp runs as ensemble members at long range and it just so happens these ones were at the milder end of things.

Will we get a white Christmas (at least down south anyway)? Odds against in my view. Will we see a cold spell between Christmas and new year? Odds heavily in favour in my view looking at the varoius longer term offerings.

Edited December 18, 2014 by Jason M

[Carlrg]

Coldies will have to wait till January for any significant cold IMO. The charts look like mush to me. Hope i'm wrong though but the promised cold just isn't getting to our shores and keeps retrograding. Some terrible perturbations on the GEFS ensembles.

Edited December 18, 2014 by Carlrg

[knocker]

This is but a fleeting visit but an uncanny similarity  between these two charts from two somewhat different sources.

Courtesy weatherbell

 

Edited December 18, 2014 by knocker

[Geordiesnow]

I did predict last night we may see up and down emotions as we no doubt will see varied output and this is most definitely the case, you can't expect the perfect run to then make it all the way to 0 hours without the usual variable changes you see at that range regardless the type of set up nevermind the more complicated cold set ups. 

 

Theres still the trend and hints things may turn colder and there is a chance it could be significantly colder but those shortwaves are a right nuisance and until we know how these are going to behave, then how can you possibly believe what the rest of the output regardless what it shows.

 

Some patience will be needed but the trend in the leading up to xmas is most definately a North-South split with Southern areas remaining very mild whilst more Northern areas could enter the colder air at times, how far South these PM shots head is open to a bit of doubt mind.

[Midlands Ice Age]

An I the only one thinking that the ECM Synoptics could deliver a great solution further down the line? Short term pain for long term gain?

 

Nope as i alluded a few post's back, To me it's looking like a stronger push of cold after the Christmas cool/cold shot.

Guys ,

 

I posted this morning re the above ...

 

It looks as though the first attempt at cold by the GFSP is far to quick for lasting cold. (Maybe give us some snow at XMAS though).

 

The GFS is still a dog's dinner  and may need until monday or tuesday before it gets the trend correct ....

 

The ECM looks to be about the right speed as Tamarra and OldMetMan have suggested as per when the atmosphere will be correctly loaded for a lasting cold/very cold spell. 

 

My post earlier said it may well follow a 1962 style run-up with a midlevel high  block off North west Scotland gradually moving into Scandanavia  and joining up with its big brother from the East. Afterwards the whole lot regressed to Iceland and we were stuck in freezing conditions for months.

 

The latest ECM now reminds me of 1956 (feb)  where the arrival of extreme cold was quick and very aggressive. A depression to the northwest suddenly decided it had had enough of fighting the block over northern europe and went on its holidaays straight over central England to the Mediterranean. The cold and gales for two days was intense with 5foot drifts everywhere. even on low ground.

 

I remember the MO didn't pick it up til late on (12hours) and it was  a great shock to many people though admittedly it was made worse because Europe had been very cold that year.

 

So don't be in tooo much of a rush bloggers . Slow and steady  is the way....

 

So as my previous post suggested we may have much to gain from the slower evolution. Its almost the longer it takes the worse (better?)  and more intense it will be.

 

MIA

[karlos1983]

Coldies will have to wait till January for any significant cold IMO. The charts look like mush to me. Hope i'm wrong though but the promised cold just isn't getting to our shores and keeps retrograding. Some terrible pertubations on the Gem ensembles.

 

ECM Mean would disagree with you..... big time 

 

 

December and cold..... not January

[nick sussex]

I think we need to see the ECM drop these western based negative NAO's operational runs ASAP, like tomorrow morning!

 

Eventually Flash Gordon loses his nine lives and the ensemble ledge which he manages to keep landing  on is no longer there.

 

The higher resolution operational is desperate to go in one direction, so far the ensembles aren't interested. The actual descent into the mild quagmire started from T168hrs tonight so I think we'll get a resolution by tomorrow evening, not perhaps fine detail wise but which trend is correct.

[MR EXTREMES]

Not buying into any cold spell perhaps fleeting cold as low pressure passes through!.

I'm more skeptical now as the charts are not nowhere as good as yesterday.

Really feeling it's going to be a close call country wide but certainly in the north.

Although we could end up with heights over the uk which may move towards Scandinavia if the lower heights manage to move into Eastern Europe.

But there is a certain shift of the pattern being further east but have a feeling a settled but homegrown cold could be the picture after Boxing Day and beyond.

[SMU]

Evening All-

 

A topsy turvy day of which I would like to make the following comments.

 

When it comes to cold spells & High level blocking the ECM has NEVER missed one. *Nearly* Every cold spell that has arisen for the UK the ECM has been ahead of the curve a good 36 / hours before the GFS, however of course every blue moon the GFS hits it first ( mainly because of the timespan & amount of runs it produces )

So at any given point if the ECM isn't on board at 144-168 ( poss even 192) then its not likely to happen. The past 24 hours have shown that every model that produces a run out to 180 has moved its solution to the ECMs out put with 'some' energy moving back west or North west over the UK.

 

Now the caution comes from the fact that every failure of the ECM where it forecast a big HLB & it hasn't delivered the GFS has always been the model leading the way on the failure before the ECM - this has been the case since the ECM upgrade ( which at times since 2013 has felt like a rather large downgrade )

 

so when we have a cold scenario in the mix at 168-216 the ECM must be on board - as this still verifies as the best. with 'some' caution, but we cannot dismiss it.

 

Todays ECM is a fairly consistent continuation of the past 3 runs ( todays 00z & yesterdays 12z/00z) - with a cold flow over the UK xmas eve - boxing day before the 'potential' of some atlantic influence slides east.

Note I put *potential* - because of the range this energy could still slide south of the uk like the GEM shows here. ( please see the 1020 shallow low pressure south of Ireland )

http://modeles.meteociel.fr/modeles/gem/runs/2014121812/gem-0-204.png?12

ECM is further North - see the 1010 low NW of Ireland.

http://www.meteociel.fr/modeles/ecmwf/runs/2014121812/ECM1-192.GIF?18-0

 

 

So there seems a cone of track from the snippet of GEM / ECM blend that will have a 24-36 hour wave of mild air on the southern flank & engaging the cold on the northern flank with possible snow.

the Operational COULD be a slight mild outlier if the ensemble suite looks a bit more like the GEM-

 

If afraid the GFS & GFS (P) is all at sea with the tracks & high pressures - its estimated to catch up by tomorrow - 24-36 hours late to the party as it usually is.

 

Post 192 ECM shows 'classic' potential which has been there for 2/3 runs-  which is vertical advection creating the upper air flow condusive to the formation of a Greenland high ( all be it slightly west based )

 

I say classic charts because they have the potential to be classic, A Greenland high covering a substantial area supported by a -EPO ridge doesn't come along every day.

So looking at the NH plot at 168 we see a very similar type of advection like 2010.

 

Heres 2010

http://modeles.meteociel.fr/modeles/reana/2010/archivesnh-2010-11-21-0-0.png

2014 ECM 168

http://www.meteociel.fr/modeles/ecmwf/runs/2014121812/ECH1-168.GIF?18-0

 

The only major difference is the location being circa 750-1000 miles west, however the net result of pressure is the same -

240 is stunning

http://www.meteociel.fr/modeles/ecmwf/runs/2014121812/ECH1-240.GIF?18-0

by then the North of the UK pretty cold

 

http://www.meteociel.fr/modeles/ecmwf/runs/2014121812/ECU0-240.GIF?18-0

 

There is no straight entry back to mild from there - the northerly flow should sharpen up & along the southern flank the jet will fire shallow low pressures -..

Note the short ENS show the Operational a milder outlier

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

Looking even closer the Wind speed of the control is the same at day 10 but the surface temp is lower so possibly low on a more southerly track.......

 

 

So in a nutshell tonight its looking pretty good - The charts are simmering & as long as that vertical advection is there at 96 we will continue to see some great charts.

 

Finally the ECM extended are out & look great as well.

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php?run=12

 

EXPECT BACKTRACKS TO COLD FROM THE GFS / GFSP /GEFS over the next 24 hours. ( especially WRT Greenland blocking)

 

regards

Steve

Edited December 18, 2014 by Steve Murr

[shaky]

That ecm mean is an absolute beauty! ! Lets start of with the 18z going in the right direction before worrying about what the ecm shows tomorrow! ! If 18z shows something better then am pretty certain ecm will ditch the western nao at 216 240 hours!! Just a feeling! !

[bluearmy]

the extended ecm ens drift the atlantic anomoly into the west of the uk. at a high enough lat to keep the uk cold. the euro trough remains and i suspect there will be a few very cold runs on the london ens later. de bilt should show a frigid control. safe to say that the control evolution very much in line with the mean (compared to the op). drops a shorrtwave in from the north which deepens across us and then slowly sinks - all within air around -5c or below. the atlantic depression eventually breaks through iberia and creates a general euro trough with the atlantic ridging into scandi. noreaster for the uk.

[nick sussex]

Please Santa can the ECM operational run tomorrow morning be that ensemble member with a maximum temperature for De Bilt of -10c! :w00t:

 

 

Or at least a more central/eastern based negative NAO, many thanks NS :smiliz19:

 

 

[Tim Bland]

Phew ! Operational ECM is almost a mild outlier agains its ensembles.

[Bristawl Si]

Confused.com

Who's interpretation is telling the truth?

[johnholmes]

posting this without having read anything since about 1700 so not sure how this post will fit in with other comments/

 

the comments are my usual into my own daily file. so not in the best of English grammar/spelling!

Noaa

6-10 and the anticipated pattern change in the main  wavelength looks to be getting under way; trough nw pacific/w of Alaska and ridge Alaska along with reasonable sized +ve anomaly, the Canadian trough is now way west of the predicted position 3 days or so ago (then s Greenland, now suggested to be towards gr lakes, ridge now shown as off ssw Greenland and largish +ve anomaly with it thus the flow into the uk is still w’ly over the uk but as trough-ridge and associated +ve with ridge edge east so the flow will turn n of west into the uk, also the flat trough e of the uk is likely to react to thses changes by extending south/sharpening into Europe. Not even looked at the 8-14 but that is what is needed to be seen there if the colder shot is to be more than a short spell?

8-14 is much as 6-10 over most of chart, indeed all of chart, with not that much change in the flow over and e of the uk showing so far but I suspect the flow will turn more n of west and extend more into Europe over the next 2-3 runs. IF the trough edges back west to be west of 10 e then it really would suggest a deep cold spell of at least a week but that is not yet predicted to happen.

Going back to the EC-GFS and only the gfs actually shows this idea in its time frame (6-10). Again if my previous comment is to occur then by 2 days from tomorrow they should both be showing this prediction.

So a colder shot for sure 6 days or so from now, after the colder shot in the run ip to Christmas perhaps or will it merge into one-we have to wait and see?

link to noaa

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

[Biggin]

Confused.com

Who's interpretation is telling the truth?

Tell me about it. Its like supporting the Palace, a rollacoaster out of control. 7 days out an no one has the foggiest for C day.

[legritter]

Guys ,

 

I posted this morning re the above ...

 

It looks as though the first attempt at cold by the GFSP is far to quick for lasting cold. (Maybe give us some snow at XMAS though).

 

The GFS is still a dog's dinner  and may need until monday or tuesday before it gets the trend correct ....

 

The ECM looks to be about the right speed as Tamarra and OldMetMan have suggested as per when the atmosphere will be correctly loaded for a lasting cold/very cold spell. 

 

My post earlier said it may well follow a 1962 style run-up with a midlevel high  block off North west Scotland gradually moving into Scandanavia  and joining up with its big brother from the East. Afterwards the whole lot regressed to Iceland and we were stuck in freezing conditions for months.

 

The latest ECM now reminds me of 1956 (feb)  where the arrival of extreme cold was quick and very aggressive. A depression to the northwest suddenly decided it had had enough of fighting the block over northern europe and went on its holidaays straight over central England to the Mediterranean. The cold and gales for two days was intense with 5foot drifts everywhere. even on low ground.

 

I remember the MO didn't pick it up til late on (12hours) and it was  a great shock to many people though admittedly it was made worse because Europe had been very cold that year.

 

So don't be in tooo much of a rush bloggers . Slow and steady  is the way....

 

So as my previous post suggested we may have much to gain from the slower evolution. Its almost the longer it takes the worse (better?)  and more intense it will be.

 

MIA

This post certainly sums up what i,v been thinking of posting tonight .i would also like to say that many of us knock the models at around about 168 hrs forward but they do sometimes latch onto something at that range ,then drop it in their number crunching only to bring it back ,tonights ECM 240 hrs could in fact turn up in about 6/7 days time .as far as GFS runs [both ]it would not surprise me that we will soon start seeing some very wild swings ,as we have seen today .So at this point tonight i think the real uncertainty starts about next fri/saturday ,one post that caught my eye tonight mentioned how good all models latched on to the late nov /dec synoptics in 2010 ,well it was awaiting ,how things are great in hindsight .still tonight at this point i feel very excited of the following interesting times ahead ,and hoping today as just been a blip on the way to a possible pattern change ,Stellas all round gang . :smiliz64: