Model Output Discussion

[Lewis]

Yes the CFS takes it into Europe first around the 13th , and brings the cold air west enough to effect the Uk by 17th. I Know the CFS is useless but nice to see it agreeing with the models in what is a very early time frame for the CFS .

Yup a lot of people may not agree but i think this seasons winter will be somewhat like the 2000 winter, looking at the current patterns now.

In 2001 we had seen some very heavy rainfall causing flooding, with severe gales between the 13-14 of December, which caused damage and disruption over England and Wales. Highest gusts included 93mph at Mumbles, and 90mph just south of me at Cranwell in Lincolnshire.

The GFS shows the same type of patterns/output with hefty LP system near by or passing over the British Isles.

Then come 27-28 of December in 2000 we had Moderate falls of snow that were widely reported, with heavy snow affecting N Ireland and Western Scotland. Glasgow and Belfast had snow laying at 20cm deep, and they was also falls of 25-35cm in parts of Lanarkshire, Ayrshire and County Antrim.

Then going into the new year the patterns continued with regular deep areas of low pressure between intervals of arctic air pushing south and also lovely systems from the east.

Between the 4th and 7th of February once again heavy snow fell across much of Scotland and North ireland and not forgetting N england :lol:, it blocked roads and railways and closing airports. To lower levels the snow was soft and clinging, and brought down power lines. A train was also trapped in drifts on the Line to Inverness and Wick. Its when Aboyne recorded drifts of upto 60cm!

Later on in that winter peiod they was further heavy snow on the 26th lasting until the 3rd of March. Deep snow was less widesread than the earlier spell between the 4th and 7th but 50-60cm fell in the lanark-carluke district, 33cm was measured at Boltshope park (county durham) and correct me if im wrong but i think Norwich got a pasting with 15cm recorded.

Then consequently that same year, we had one of the wettest summers on record with thunderstorms and flash flooding between, it was July that was a month that delivered heavy rain and thunderstorms, although a majority of the flooding was due to torrential rain (flash floods). Then come December again in 2001 further heavy snow started in Scotland althoguh it was mainly confined to Scotland. Then as we hit January in 2002 we started to get further large LP systems with very strong winds/severe gales in the N again.

I honestly think over the next 9-10 months we will experience conditions and patterns to what we experienced in Winter 2000/2001.

Lewis

[Don]

So, will the ECM join in the party fun or will it be a party pooper and introduce us to Uncle Barty?!

:lol:

Good to see runs like tonight's GFS, but it will be a fair few days before I get excited about proper cold prospects. Interesting though to say the least.

Edited December 4, 2009 by Don

[SMU]

Great!

Just what I wanted!

The building blocks are starting to fall into place!

So far so good on ECM

INLINE with GFS @ 144.....

S

[Mark Bayley]

ECM looks good to me at T144.....

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1

[yamkin]

I think the GFS is developing the set-up too quickly, but it shows the territory that we could be heading towards. With heights clearly expected to rise in the Svalbard region, it opens the game up in a way that has been denied to us so often in the christmas pudding.

I see your point regarding the set-up being too quick, but the trend has been there on and off for a over a week now. As for your famous 'christmas pudding' words, don't forget that the same 'christmas pudding' words were also used back in the 1940's!!!

[snowmadchrisuk]

ECM looks good to me at T144.....

http://www.meteociel.fr/modeles/ecmwf.php?ech=72&mode=1&map=1

ECM great at +144 , If you look at the angle of the Atlantic trough , you can see it's Eastward progress has been halted . This is almost muti model agreement out to +144

[Iceberg]

Yep in the important time frame 120-144Z maybe even 168Z ECM has the Jet and WAA in the right place, anything beyond that would be a bonus eye candy wise, but not particularly important.

[snowmadchrisuk]

Yup a lot of people may not agree but i think this seasons winter will be somewhat like the 2000 winter, looking at the current patterns now.

I honestly think over the next 9-10 months we will experience conditions and patterns to what we experienced in Winter 2000/2001.

Lewis

I remember that winter , I was living in Weston-Super-Mare and we even had snow on the beach . But to be honest I am leaning more towards Jan 87 at the moment.

[tinybill]

looking deep in to fantasy land for the run up to xmas its looking very tasty at the moment

[SMU]

Yep in the important time frame 120-144Z maybe even 168Z ECM has the Jet and WAA in the right place, anything beyond that would be a bonus eye candy wise, but not particularly important.

ECM says no........ 192 the shortwave stops the ridging into the arctic.... pity- :lol:

I suppose though the ECM has backtracked around the 144 range-

Steve

Edited December 4, 2009 by Steve Murr

[Lewis]

I remember that winter , I was living in Weston-Super-Mare and we even had snow on the beach . But to be honest I am leaning more towards Jan 87 at the moment.

In which had one of the coldest periods of the 20th century :lol:?

The 12th of January max temps were widely between -6 and -8, and at Warlingham in surrey the temp climbed no higher than -9.1 !! and its also when the Isles of Scilly recorded a minimum of -7c! They was also some very heavy snow for the SE during that period.

Pushing your neck out a bit there aint you mate

Edited December 4, 2009 by Storm Force Lewis

[Snowstorm1]

ECM says no........ 192 the shortwave stops the ridging into the arctic.... pity-

I suppose though the ECM has backtracked around the 144 range-

Steve

Yes steve and that is the most important thing for now and i would have been much more worried if it hadnt come into line at +144 range but it has so im more confident now :lol:

[SMU]

Im going to stick my neck out here-

ive seen the ECM out to 240- & whilst the initial spoiler low gets in the way I dont think its enough to overide the background signal of the plunging modality of the AO-

ECM is exciting 216 & 240...................

Steve

[Frosty.]

The UKMO model if it were to run past 144 hours would most likely give a similar pattern to the GFS 6z

I think the ukmo T+144 hour verification record is very poor and what the models have shown today is that things are wide open for significant changes once the high builds, the 6z parallel run was not just a one off fluke as we are seeing now with the gfs 12z op run, very intriguing times ahead but because it's the uk the most realistic outcome will probably be a near miss but i'm hoping for something severe like most on here. :lol: :lol: bring on the blizzzzzzards and pipe busting frosts.

[bluearmy]

ECM says no........ 192 the shortwave stops the ridging into the arctic.... pity- :lol:

I suppose though the ECM has backtracked around the 144 range-

Steve

the ecm has been keener to extend atlantic energy ne and it rarely flips its output below T168, prefering to backtrack more slowly. Of course, this evolution remains entirely plausible and may well deliver via retrogression to greenland and a northerly

[Mark Bayley]

Although the ECM isn't perfect its a step in the right direction and an improvement from earlier Exciting times ahead!

Edit: Infact looks quite good from 216 plus as Steve M says !

Edited December 4, 2009 by mark bayley

[yamkin]

IMO the Atlantic trough is to far east on it , and Gfs has blocking as far west as Greenland at +144 . The UKMO in my oppinion could end up with a bartlett , but hope I am wrong , and it is not exactly the best model anyway in these situations. The only person that we will have to bow our heads to if this came off would be TEITS .

JH has always said that we should look at the trends. Over the years, TEITS always looks at the trends.

[Iceberg]

The might be some debate about the ECM, but I agree with Steve, in the reliable timeframe it backs up the GFS, from here cold is a very strong probability.

This is the 240 500 chart from ECM I've put in the likely Jet direction and the strong ridging arctic high coming down from via Iceland.

If ECM went out as far as GFS is would be cold.

[Ben_Cambs]

The GFS charts are showing improvement, an exciting 2 or 3 weeks ahead of us!

[loophole]

Will settle for that ECM, its alot better than the 0z so trending the right way

[Glacier Point]

Full update later on when the ensembles are out....

Deep convection has broken east of the Dateline, cue GFS outputs like we are seeing.

http://cawcr.gov.au/bmrc/clfor/cfstaff/matw/maproom/OLR/m.3d.html

For those who think the ECM is no good, mark the positions of the upper lows through t144 - t240. They retrogress which means the entire circulation across 60N is becoming responsive to the large +ve height anomaly across the Arctic.

[TEITS]

Only just seen the 12Zs due to watching the World Cup draw.

Im delighted with this evenings model runs. However the chart of the day for me has to be the Iceland ensembles.

http://charts.netweather.tv/ensimages/ens.20091204/12/prmslReyjavic.png

The SLP mean had increased by a whopping 10mb over these past few days, as more and more members indicate pressure being high over this region. Im convinced our weather should become influenced by high pressure rather than low pressue from around the 12th onwards. As for a bitter E,ly, well im going to keep my thoughts to myself for the moment as I don't want to put a curse on it!!

[ChartViewer]

Hi,

NOAA go for the formhorse ECM and those shortwaves may scupper any chances of cold.....Possible backtracks GFS in a couple of days............Unless the ECM comes totally on board I can see the GFS Model backtracking from the Easterly scenario by Monday.

Regards

CV

[Sawel]

I think the ukmo T+144 hour verification record is very poor...

The ECM is the only model that consistently beats the UKMO at +144 hours. The UKMO performs better at +144 hrs than the rest of the models.

You'll find the relevant verification stats on this site http://www.emc.ncep.noaa.gov/gmb/STATS/STATS.html

It's unfair to say the UKMO verification record at +144 hrs is very poor.

[Stu_London]

Agree regarding the reliability of FI.

Disagree with the comments on ensembles - 4 or 5 members are showing some sort of coldish easterly, albeit not with the same intensity of the operational run. This far out, with so much that could go wrong with a set up like this, I think that is the best you can hope for.

If the event, or something similar to it were to come off, I would be expecting an additional 1 or 2 members to get on board per day until most were there at around +144.

I would caveat that by saying we have seen similar set ups (especially easterlies) evaporate at shorter notice than that with almost 100% cross model and ensemble support, so I wouldn't be saying anything would be guaranteed until about +36

Not there yet and could all go wrong but we now have the majority of the ensembles on board for a cold spell as at the 12z GFS. Of those most go cold and stay cold.

Chances have perhaps risen to around 25% - 30% that something might actually come off from the current setup and we probably only need to wait another 72 hours for a clearer indication of the outcome.

At the risk of sounding a bit like BFTP :lol: , I'm liking my post of 2nd December 2009 (above)