Model Output Discussion - 18z - 25th Nov onward

[fergieweather]

don't they always back the UKMO though regardless ?

No. Fax charts are routinely at odds with UKMO-GM modified output and this proves a very regular discussion point when we create synoptic charts for TV use.

And PS re wider discussion: Key part of UKMO thinking into the longer MR is not solely EC Monthly (GFS beyond circa 8 days not really rated) but MOGREPS. The latter's strong signal from MOGREPS-15 has remained a critical driver behind recent UKMO 10-15d prognosis alongside that from EC32.

[ITSY]

Well for the South I'd agree this is not a good run. For the North, well -4/5 uppers never really leave the shores, meaning that when the actual pattern breaks down the cold remains and we get dumps of snow. Still, I would be frustrated once I returned south from the 8th.

Don't sweat, the morning will breed happiness. I'm sure.

[Harsh Climate]

Looks good to me, the track of low pressure's are way south of where they would normally be, with us on the northern side, could spell a lot of snow!

[Jonan92]

00z run will tell us if the blocking happens or not. GFS, UKMO, Nogaps and Brazilian say that it happens, on the other hand, ECM, GEM, JMA say that it brokes down

[TEITS]

Someone asked earlier if the ECM has ever been this wrong at this timeframe. Well the answer is yes it has and I shall use the Dec 2010 as an example.

http://www.wetterzen...00120101218.gif

The ECM made a right pigs ear out of modelling this because I remember vividly as it caused many arguments. The ECM consistently progged that LP to be much further NW into the Atlantic and was actually predicting mild SW,lys! I remember because myself and Nick S were saying the further SE the better and this led to being accused of SE bias.

Back to the GFS and I can't help but say shades of Dec 1978 in F.I

http://www.wetterzen...s/Rtavn3361.png

Although im sitting on the fence I am leaning towards the UKMO being right here.

Edited November 25, 2012 by THE EYE IN THE SKY

[lorenzo]

Met Office stick with their model with the fax charts,

120 hours

This is worth sticking with and bookmarking IMO.

[weather_it_will]

Potential Epic FI

[johnholmes]

this may help a few shredded nerves-still valid

http://forum.netweather.tv/index.php?app=core&module=attach&section=attach&attach_id=145843

[Cloud 10]

The mighty WMC (russian model) says NYET to the ECM!!

[Duane S.]

Reference to those saying the MET always back their raw model, they do not. I was never expecting the fax charts to suddenly reflect the ECM tonight but had they given it any credit we would have seen a fair step towards it. They have obviously dismissed it (for now at least!)

[johnholmes]

00z run will tell us if the blocking happens or not. GFS, UKMO, Nogaps and Brazilian say that it happens, on the other hand, ECM, GEM, JMA say that it brokes down

Brazilian-gawd that is desperation, never seen that quoted before!

No. Fax charts are routinely at odds with UKMO-GM modified output and this proves a very regular discussion point when we create synoptic charts for TV use.

And PS re wider discussion: Key part of UKMO thinking into the longer MR is not solely EC Monthly (GFS beyond circa 8 days not really rated) but MOGREPS. The latter's strong signal from MOGREPS-15 has remained a critical driver behind recent UKMO 10-15d prognosis alongside that from EC32.

thanks for a touch of reality and fact Ian

[LomondSnowstorm]

Has there ever not been?

In terms of accuracy then of course it is dodgy, in terms of snow and cold it's time to get out the shovel if you live in the northern half of the British Isles.

[nick sussex]

Reference to those saying the MET always back their raw model, they do not. I was never expecting the fax charts to suddenly reflect the ECM tonight but had they given it any credit we would have seen a fair step towards it. They have obviously dismissed it (for now at least!)

Well if you've seen those charts I posted on the previous page both USA forecasters and the UKMO think the ECM is a pile of tosh!

Lets hope that is the case, it really will be nailbiting stuff tomorrow morning!

[The Eagle]

Hopefully not a stay of execution. Ultimately it comes down to the 00z's. Very important runs tomorrow.

Edited November 25, 2012 by The Eagle

[damianslaw]

Interesting times for model watching. Reliable timeframe 120hr- 144hr period significant differences between ECM and GFS/UKMO, the former scuppers the chance of a sustained cold attack (at least for a short time..), whereas the latter two suggest a very amplified pattern reinforcing the ridge to the west enabling very cold uppers to descend down from the arctic as we enter December.

As others have stated the key feature appears to be the developing low pressure cell coming out of NE USA/SE Canada and how deep it becomes, the deeper the better as it will help to prop up the ridge and move NW rather than eastwards.

I do rate the GFS when it comes to developments around Greenland, it does outperform ECM, however I normally rate the ECM when it comes to the medium timescale of 120-144 hrs. The fact UKMO is siding with GFS is significant. Will the ECM side with UKMO/GFS tomorrow, will UKMO and GFS revert to ECM synoptics...

If the ECM synoptics do verify it is hardly a mild outlook, indeed it would be a cold zonal pattern with lots of polar maritime air digging in behind the fronal features and the jet is likely to stay on a fairly southerly track for some considerable time.

[Severe Siberian icy blast]

Someone said poor fi, take a look again, northern blocking all the way, southerly tracking jet, when the two troughs merge in early fi , even that would likely bring wet heavy snow , the uppers -2/3 , not that it matters because its only trends we look for, and the trend is for northern blocking to dominate, and there will be snow.

Oh and that snow event on the 12z for the wkend is there again for the midlands.

[Duane S.]

00z run will tell us if the blocking happens or not. GFS, UKMO, Nogaps and Brazilian say that it happens, on the other hand, ECM, GEM, JMA say that it brokes down

I'd like to think it would tell us Jonan but I think we have to wait a day or so longer, there will be more twists and turns beyond the 00zs (after all, why would change the habit of a lifetime! )

[If Wishes made Weather]

The 18z at circa 252 develops a 'shortwave' mid Atlantic and moves it west. It eventually is shown to track through the channel.

Ideally we would want these features to be 300 - 500 miles further south (globally a tiny movement) to allow the nicely developed pool of cold air over Scandinavia and Eastern Europe to be sucked westwards over the North Sea towards us. It is heartening though to see how this initial go at some cold weather (right on the cusp of winter) develops a state of affairs that will/could make a subsequent second or third shot all the much more potent.

[TEITS]

No. Fax charts are routinely at odds with UKMO-GM modified output and this proves a very regular discussion point when we create synoptic charts for TV use.

And PS re wider discussion: Key part of UKMO thinking into the longer MR is not solely EC Monthly (GFS beyond circa 8 days not really rated) but MOGREPS. The latter's strong signal from MOGREPS-15 has remained a critical driver behind recent UKMO 10-15d prognosis alongside that from EC32.

Im slightly confused because I always thought the MOGREPS was mainly used for short range forecasts only upto 2 days.

[camiscool]

i meant poor fi as in the atlantic breaking through at the end...?

[SLEETY]

MAJOR BREAKING NEWS FROM THE USA!

The final bulletin from our USA correspondent, remember this is not computer generated but done by the duty forecaster having looked at all of todays outputs including that nauseating ECM!

Take a look at whats near Nova Scotia on day 4 then enjoy the rest:

Day 5

Day 6

Lets hope for an ECM backtrack tomorrow.

Very interesting.The forecaster going for that low pressure to move northwards and not eastwards as the ECM has suggested

[LomondSnowstorm]

i meant poor fi as in the atlantic breaking through at the end...?

I apologise, yes that's true, but then it is +384, when it goes from being unreliable to just plain silly.

[Jonan92]

Watching the FI makes nonsense when we don't know for sure if the blocking will happen or not

[lorenzo]

No. Fax charts are routinely at odds with UKMO-GM modified output and this proves a very regular discussion point when we create synoptic charts for TV use.

And PS re wider discussion: Key part of UKMO thinking into the longer MR is not solely EC Monthly (GFS beyond circa 8 days not really rated) but MOGREPS. The latter's strong signal from MOGREPS-15 has remained a critical driver behind recent UKMO 10-15d prognosis alongside that from EC32.

fergieweather - does mogreps -15 include the new stratosphere layering from Glosea-4 that was verifying before introduction?

[Duane S.]

Well if you've seen those charts I posted on the previous page both USA forecasters and the UKMO think the ECM is a pile of tosh!

Lets hope that is the case, it really will be nailbiting stuff tomorrow morning!

Yes I did see them Nick (great find by the way!). Possibly better news than the 18z tonight as we have the European based ECM vs (amongst many other things) charts drawn up by a Meteorologist(s) with local knowledge. I know who my money's on!