Model Output Discussion 12z 18/10/2012

[Eskimo]

Is the UKMO a good model? Seeing it is affiliated with the Met Office, surely we would consider it being quite reliable?

[BLAST FROM THE PAST]

UKMO is the model I would want on side...however, the GFS did pick up this coming spell first and it must now be worth considering what it is now seeing.

BFTP

[Met4Cast]

UKMO is the model I would want on side...however, the GFS did pick up this coming spell first and it must now be worth considering what it is now seeing.

BFTP

Agreed - Particularly as the 12z is supposed to be one of the more reliable runs too. If the ECM sides with the UKMO then it's going to be a tough call to be honest, GEM is rolling out now, it'll be interesting to see which way that goes

[Gavin Hannah]

It would be good to see the models go with a sustained HP scenario as we get closer to next weekend.

Having been away for a few days I've only had a chance to look at todays 06Z and 12Z GFS runs. Could it be that as we start this week, the models pick up on possible scenario where the HP decides to become stationary keeping us under a sustained northerly flow?

[Alan Medlock Valley]

Spot the UK - http://www.meteociel.fr/modeles/jma/runs/2012102012/J168-7.GIF

[Skyraker]

@+144 the UKMO model is the one i'd want to see on side, it just seems to verify better at that range than the GFS which i've seen break many hearts with a sudden change @ +72.

It will be interesting to see where the ECM stands in an hour or so.

Is the UKMO a good model? Seeing it is affiliated with the Met Office, surely we would consider it being quite reliable?

Edited October 21, 2012 by Skyraker

[Zenarcher]

Is the UKMO a good model? Seeing it is affiliated with the Met Office, surely we would consider it being quite reliable?

Most people mainly look at the GFS, ECM and UKMO 'the main three' because I believe they perform the best on average.

[Don]

Well the UKMO is normally the party pooper in these situations so the fact that it's showing what it is is certainly something! We await the ECM......

[BLAST FROM THE PAST]

I can see where the GFS is coming from inasmuch personally with my view looking forward I see a a month of big swings so I don't see prolonged weeks of blocking also no steamrolling cyclo. I do think its too progressive though.

BFTP

[lorenzo]

GEM also looking easy on the eye ..

What's the rule of thumb 2/3 out of the big 3 to be on board, or is it a Top 5 now including GEM re: Verification and JMA re: Fergieweather input earlier?

[Summer Sun]

UKMO looks perfect at 144h for cold and maybe some low level snow?

GFS on the other hand................

[bluearmy]

The JMA is closer to the UKMO evolution than the GFS evolution, with cold air digging down from the north next weekend, bringing an increased risk of wintry PPN to the north by week 2.

http://www.meteociel...&nh=1&archive=0

http://www.meteociel...&nh=1&archive=0

http://www.meteociel...&nh=1&archive=0

yesterdays run. todays still an hour or so away.

note that we are entering 'whats the most reliable model' territory at day 6. if the main ones disagree then who knows? tbh, its not a huge sypnotic difference between them but it does have big ramifications for the n half of the uk.

[Met4Cast]

GFS seems to be out on its own at the moment compared to the other 12z runs - Can't be dismissed since it was first to pick out this cold spell with no support from other models or even its own ensembles so we can't assume its wrong

GFS

UKMO

GEM

Edited October 21, 2012 by Daniel AKA WMD

[BLAST FROM THE PAST]

We are talking 6 days out here, to me GEM after t144 will go with GFS, UKMO looks like yesterdays outstanding runs. Its why I am very cautious re models' reliability. Why should they differ and chop and change? one two or three are wrong......why its only 6 days?

BFTP

[Gavin Hannah]

Will be looking forward to the ECM. On it's earlier run it threw up a northern low at t.192

Will be interesting to see where it came from and if it keeps it in its next run.

[snowking]

For reference:

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day6_HGT_P1000_G2NHX_12Z.png

Current 30 day running mean places 12z runs @ day 6 as follows:

1) ECMWF

2) GFS

3) UKMO

4) JMA

5) GEM

However, the most recent data:

1) GEM

2) ECMWF

3) UKMO

4) = GFS & NOGAPS

5) JMA

The second set of data is merely the most recent data set on the graph linked to, and so is arguably less objective than the 30 day running mean

SK

[The watcher]

I could see ECM being a halfway house between GFS and UKMO.

6 days is still a long time to pin down exact details, so a hundred miles here and there is nothing at this stage. We are on the risky side (West) of this PV piece and the slightest of margins makes all the difference, especially considering we usually see an Eastward correction nearer the time in most cases.

[Continental Climate]

http://www.wetterzentrale.de/pics/Rukm1441.gif If only it was................

[Thundery wintry showers]

Before we get to this upcoming cold snap/spell (length is still yet to be determined) we have a few days coming up which, for most of us, would be best described as mild and muggy. We will have high pressure in charge of the weather but a weak slow-moving front, which will bring grey skies and drizzle northwards tomorrow, and those grey conditions will hang around for most of us on Tuesday and Wednesday- the weak late-October sun probably won't make much of an impression on the cloud sheet although the drizzle will tend to fizzle out. The exception will be central and northern Scotland, where a mix of sunny spells and fog patches can be expected, and chilly nights- in these setups some places will see plenty of sunshine while others will have persistent fog for much of the time.

Most of the model runs that I've been seeing recently showed notably cold weather for late-October, but mainly dry due to the proximity of high pressure. The UKMO at T+144 is one of the snowiest-looking charts that I've seen progged in the last week, and certainly the first chart inside T+168 that could well produce widespread snowfall. I think one or two Arctic incursions, bringing notably cold but mainly dry weather, and lasting a couple of days, is quite a probable scenario- for widespread snowfall the high pressure would need to be further west than most recent runs have shown, as illustrated by the latest Met Office run.

Edited October 21, 2012 by Thundery wintry showers

[Matty M]

Quite exceptional cold pool for this time of year over Svalbard area heading directly towards us.

Come this way please!

[Isolated Frost]

Up to +72 on the ECM and it's looking less progressive but quite close wrt the HP cell and vortex tint with the UKMO. The GFS is a slight bit worse than both.

[January Snowstorm]

At +96hrs ECM identical to UKMO, in fact a touch better!!

[snowfall09]

Up to +72 on the ECM and it's looking less progressive but quite close wrt the HP cell and vortex tint with the UKMO. The GFS is a slight bit worse than both.

Could i have a link this this model please

[Summer Sun]

The are showing snow showers getting as far south as the north east england on Friday, the next few days is going to make some interesting viewing in this thread to see what the models do

[Matty M]

At +96hrs ECM identical to UKMO, in fact a touch better!!

Cold Spell chart watching on the 21st of October, who'd have believed it eh JS!!

ECM slightly different to UKM at 120hrs, cold air not as further east.

Main crux seems to be less defined Block and a slightly less deep French LP.

http://meteociel.fr/modeles/ecmwf/runs/2012102112/ECM1-120.GIF