Model Output Discussion - January 12th.

[Frosty.]

Yes the Ecm 12z has not let us (cold fans) down, -8 T850 hPa in FI, it keeps hopes alive of a proper cold spell but we still have a superficial cool snap this weekend following all the very mild weather this week although it now looks as though there will be more cloud floating around the uk than earlier thought so no wall to wall sunshine and therefore the frosts will probably be more patchy in nature as a result, at least it will feel like winter for a change.

[Summer Sun]

One of the best updates this winter from ECM cold and frosty this weekend and into next week before a brief milder spell and then a return to the colder and maybe snowy weather a very interesting week coming up maybe a week or so away from the first snow feast of winter.

[kold weather]

Yes ECM is very good for sustained cold this eveing, that would give a good 7-10 day cold spell before it comes under any real pressure.

The differences between the ECM and the GFS over the Arctic is HUGE. That appears to be the key zone. if we get some sort of split or a major diasplacement of the PV then we will probably be in buisness. The problem is the GFS keeps the PV rooted to Greenland with only minor wobbles here and there which isn't good enough for the UK to tap into anything other than weak toppler attempts.

[mulzy]

GEFS parallel ensembles much better than previously...

http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=12&ville=Londres&runpara=1&type=0&ext=1

NOGAPS decent.

JMA prettly similar to ECM.

Lots of positives this evening!

[ITSY]

superb run from ECM op - the fact that it has produced such synoptics for 2/3 runs in a row whilst the GFS has chopped and changed indicates that perhaps it is handling the situation better. Certainly rule nothing out even after the dross of the GFS 12Z. Wait for the ECM ensembles now and see where it fits in - but it certainly produces what a lot of us (including myself) are after.

[russ49]

i know all models except the GFS are in approx agreement. but to play devils advocate can you see the GFS being anything like right or some sort of middle ground, i personally am a cold lover but just had this niggle

thanks

Russ

[kold weather]

Most GFS ensembles bring down at least some cold between 216-240hrs and whilst its not long lasting it does make an impact on the mean 850hpa temperatures as well as on the synoptic charts.

Still long way to go, really got to see at least a couple more days of runs like the 12z ECM before we get too excited about the prospects.

[ITSY]

GEFS parallel ensembles much better than previously...

http://www.meteociel...=1&type=0&ext=1

NOGAPS decent.

JMA prettly similar to ECM.

Lots of positives this evening!

excellent ens from GEFS there - mean hovers at -5 uppers for london for the forseeable after the 21st. With JMA, UKMO, GEFS ens and ECM pointing the same direction, i'd expect upgrades from the GFS op for this evening's pub run - but who knows, it may have it right. don't rule anything out yet.

[nick sussex]

The ECM is excellent and better than this mornings output and would deliver UK wide.

It's a shame the GFS refuses to go along with this as that casts a degree of uncertainty which I think most people have had enough of by now. The key to the ECM outcome is the PV splitting and enough amplification to dig the trough se'wards.

Although the ECM is the best global model at 168hrs I think we're going to have to put any champagne on ice and wait to see what happens with the GFS tonight and tomorrow.

Sometimes you'll find the GFS 18hrs run trend across to the ECM when theres a disagreement, and I certainly hope thats the case tonight.

[cooling climate]

What I really like about the t240 ECM chart tonight if it verifies of course is that it could very well

be a prolonged cold spell with pressure building to the east ready to move westward I would

imagine.

[Matty M]

Yes i am cautiously optimistic tonight as i always expected when i finished my exams on the 20th Jan i would be rewarded with a cold spell to watch!

[manonthegrassyknoll]

Just to help anyone confused in this thread here are a few points.

1. An E,ly is now looking very unlikely within the +144 timeframe.

2. If a cold spell does occur it looks more likely to develop with a NW,ly intially but if the trough sinks far enough S we shall have an E,ly on the N flank. This is progged to occur between +168/+192.

3. Big disagreement with the GFS/ECM but at this stage the combination of other models that support the ECM plus the consistency of the ECM makes me rather dubious of the GFS output.

Thank you TEITS, this sought of post is extremely helpful for people like me who are trying to learn.. it would be nice is this sought of thing happened more frequent..

Chris..

[Frosty.]

I agree with Darren (KW), the major difference between the ECM and the GFS is how they handle the AO. The GFS wants to amplify the pattern at several times during its run but the low heights at Northern latitudes will not allow it. If this were prior to 2008 you would bet your house on the GFS and dismiss the ECM as pure fantasy.

As for talking about snow distribution, that's ludicrous given how easterlies (i.e unpredictable) have played out in recent years.

It's a shame we won't know which model is right for a few days yet, the gfs is continually delaying the onset of a much colder pattern until deep into FI where logic goes out of the window, we just have to pin our hopes on the ecm and hope it stays on it's current track.

[ANYWEATHER]

A very confusing picture, from the model output tonight!! Gfs keeps the settled, shallow cold well into next week, Ecm breaks the settled conditions a lot quicker. The theme from both models is "perhaps" a breakdown from the models from the NorthWest sooner or later with some good shots of PM air, perhaps the first obstacle to get over,as for an Easterly ......we will have to wait a while....... :rofl:

[weathe20]

Seems there is good consistancy from the ECM and other models. The big guns here tonight seem confident of a trend to cold....but surely there is niggling feeling that

the GFS is still not on board? Think Ian Brown is hoping this niggling feeling comes to reality!

[JP1972]

Sorry to ask what might seem like a silly question.

All you knowledgable ones among us all, if you had to stick your neck on the line right now which model would you back to come to fruition and why?

Thanks.

[AWD]

http://yfrog.com/oe85hlmj

Interesting message received from BBC Local Weather Presenter Ian Fergusson!

ECMWF plume chart for Reading shows strong signs of a colder, more unsettled spell developing later this month

[bluearmy]

That mjo jan analogue looking more and more relevant.

[Cloud 10]

The ECM continues to be the pied piper of the model world at the moment,leading an ever increasing number

of coldies to the promised land!

It would be nice to see a change in the metoffice 6-15 day outlook tomorrow to reflect the ecm output.

[ChartViewer]

Glacier Point and Netweather probably getting the Havana cigars ready as so far they have nailed the Winter forecast up till now although 6 weeks to go but it is looking good with upstream patterns as they are.....However GFS yet to come on board although i reckon it will to an extent tonight....

Regards

Edited January 12, 2012 by ChartViewer

[Frosty.]

Seems there is good consistancy from the ECM and other models. The big guns here tonight seem confident of a trend to cold....but surely there is niggling feeling that

the GFS is still not on board? Think Ian Brown is hoping this niggling feeling comes to reality!

i don't think that's fair, if the cold spell does firm up, ian will go with the flow, I don't think he's anti cold.

The models are still not fully behind a pattern change so it's nervous times ahead for all those waiting for the first widespread cold spell of the winter so far as we reach the halfway point.

[snowking]

Sorry to ask what might seem like a silly question.

All you knowledgable ones among us all, if you had to stick your neck on the line right now which model would you back to come to fruition and why?

Thanks.

Ill help to answer this by reposting what I've just posted on another forum:

Just to give you an idea of current model accuracy...

Below is the 12z verification stats (simply put, how accurately the models have predicted the actual outcome from a number of days away) for heights at 1000hpa (roughly sea level), in the Northern Hemisphere (note: the higher the figure at the bottom left of the diagram, the better the model has performed):

As early as day 1 we see differences:

http://www.emc.ncep....0_G2NHX_12Z.png

With the GFS behind even the cannon fodder such as JMA and EQUAL TO THE NOGAPS!! (and how often is it anyone gives this credit - other than Nick Sussex straw clutching to prevent reaching for the prozac earlier)

By Day 3:

http://www.emc.ncep....0_G2NHX_12Z.png

UKMO and ECMWF still lead the way (with ECM in first place) over the 30 day average far ahead of the GFS, as well as remaining better verifying than the GFS more recently (you can see this by concentrating on the last few plots of the graph - the better verification will become easier to see as we move out to days 5 and 6)

Day 5:

http://www.emc.ncep....0_G2NHX_12Z.png

ECMWF miles ahead of the rest, with UKMO narrowly ahead of the GFS, which is equal to the JMA (again, how often do we take the JMA seriously? - well according to this at the moment it should be just as serious as the GFS). Though you will notice the more recent general drop off on the graph, showing the present uncertainty arising.

Day 6:

http://www.emc.ncep....0_G2NHX_12Z.png

JMA and GFS still level pegging, with ECMWF miles better and UKMO a decent second. Though lets note that on the last update the NOGAPS shot up to equal verification percentage with the ECMWF (hooray for the underdog)

By Day 8:

http://www.emc.ncep....0_G2NHX_12Z.png

The ECMWF still comes out on top as it and the GFS leave the JMA flagging (some work to do there Mr. Japaneese Met Office), but the most notable thing about this chart is the remarkable inconsistency by the GFS, indicated by the massively varying solid black line.

So as a conclusion - ECMWF is presently (and over a 30 day average has constantly been) the favourite, a win for the GFS would seem unlikely....but then again this is the weather we are talking about

SK

Edited January 12, 2012 by snowking

[KTtom]

I'm going for the +192 hours ECM chart tonight as the chart of the day, the 216,240 are even better, but as the easterly looks a long shot, at least initially, the ECM shows the holy grail for cold i.e. high pressure heading to greenland. IF this was to happen then cold is pretty much guarenteed .

[kold weather]

Those plume charts from the ECM ensembles is interesting, it sorta backs up the idea that the 12z/00z ECM operational runs had, in that the upper trough comes down over the UK/just to the east and eventually by 192-240hrs starts to introduce much colder air down.

Hopefully the 18z will fall inline with the ECM!

[phil nw.]

We can see where the models show differences clearly at T144hrs.

The GFS keeps the jet angled NE with the Azores block linking to the Russian high minimising any troughing diving into Europe.

The ECM continues with the 00z trend of splitting the highs and the Azores high extends NW making room for the rest of it`s evolution to a colder pattern.

The UKMO looks to be going more towards the ECM with the gap created for the troughing to extend into Europe ,maybe a little slower in it`s evolution.

There is still time for some detail to change particularly as modelling heights around the Arctic is tricky.

The balance of energy distribution here is so important to the rest of each runs output.

.If the jet stays north as shown by the GFS then a cold pattern would at the very least be delayed.

However it is on it`s own in keeping the Low Heights extending eastwards towards Svalbard at this timeframe.

The ECM and UKMO are both showing the retreat of the vortex at this point thereby we see that troughing going SE off the Vortex and not north east or east as per the GFS.

The ECM Op.run is now starting to show consistency in the last 2-3 runs and broadly follows the medium range 500hPa output wrt placing of the upper features by days 6-10.This is last nights CPC 500hPa ht. anomilies.,tonights not yet out, but this output is much less volatile and it does gives an idea of the expected pattern.

With the UKMO and ECM runs handling the vortex in a similar fashion and the supporting data you would have to favour their outputs at the moment.

As ever we need all the models on board -preferably by the weekend and then at last we may be looking at something colder by week 2.

Edited January 12, 2012 by phil n.warks.