Model Output Discussion: 12Z (20/11/12) And On...

[weather eater]

The BOM got talked about rather a lot the year before last, but I got the impression that it was found a bit wanting, still always nice to see and maybe it’s on to something this time.

[nick sussex]

The BOM got talked about rather a lot the year before last, but I got the impression that it was found a bit wanting, still always nice to see and maybe it’s on to something this time.

Yes we only bring it out when it shows good synoptics! Normally its left festering in the cannon fodder model section!

If I was in the UK and offered an outcome at 240hrs that would be it, i'd take it and run to the nearest sledge shop!

[johnholmes]

Meantime in the real world the upper air charts continue to show the most probable evolution, upper high edging into the NW as the upper low edges ESE by about T+240 (10 days time)

[TAFKAP]

http://modeles.meteo...nh-0-234.png?00

PS the BOMB run today as ive renamed it is the form horse- I always said those Aussies had the best model!!

Good old Bureau of Meteorology! I wonder what its verification stats when it comes to forecasting Antipodean weather are? Still, fingers crossed that verifies, it may just become this season's favourite if it does. Trust the Murr-man to find the best chart for cold lol

[weather eater]

Yes we only bring it out when it shows good synoptics! Normally its left festering in the cannon fodder model section!

If I was in the UK and offered an outcome at 240hrs that would be it, i'd take it and run to the nearest sledge shop!

Well you never know Nick, if GP is right then it maybe that the models are still significantly underplaying the changes we are about to see, at least his post last night suggested that all output post 144hrs was a likely to be as useful as Steve’s chocolate teapot/hammer.

[phil nw.]

Anyone looking for cold this morning really shouldn`t be disappointed with the 00z runs.

The conveyor bringing the colder air from the north east starting to be modelled just outside the reliable period now around T144-168hrs.

GFS at T168hrs for an example

UKMO at T144hrs showing nicely with the 500hPa pattern too

ECM would get there eventually

Trough extension showing up from Scandinavia on the all the models at the end of next week.

Small differences with details but a good trend to bring the cold in a few days afterwards.

We are getting there but note that next week is the changeover period.

If the pattern evolves as showing currently then look for proper cold come the new month.

[weather eater]

Meantime in the real world the upper air charts continue to show the most probable evolution, upper high edging into the NW as the upper low edges ESE by about T+240 (10 days time)

That suggests to me that this morning’s ECM is nearer the mark in its general theme than the GFS.

Edited November 21, 2012 by weather eater

[Cloud 10]

http://modeles.meteo...nh-0-234.png?00

PS the BOMB run today as ive renamed it is the form horse- I always said those Aussies had the best model!!

It even comes with cold 850's..

http://modeles.meteociel.fr/modeles/bom/runs/2012112100/bomnh-1-240.png

[BLAST FROM THE PAST]

Yes A good haul this morning from the top models-

The best news is the Allignment of the Arctic high- alligning the cold directly west South West into Scandi-

the UKMO very fast with this - ECM a few days lag behind.- GFS in th middle.

Again a few days before we get total clarity, but I feel the interest has perked up a little today- just the ECm that was a little disapointing in the mid term, a good recovery at the end with the -20c isotherm getting into the low countries...

Looking good for the start of December now.

IGNORE THE 06Z RUN!

S

Hi Steve

The UKMO has come well fast compared to yesterday...but that was the pattern you saw it would develop into. It just seemed slow to me yesterday.

These days since I think Fergie said so, I am really taking notice of the JMA. And looking at its t192 today the trough gets there sinking ESE with pressure rising to NW then N and NE. That looks very plausible route to me....and a very good route too

I think the speed is about right too, end of month into new month.

BFTP

Edited November 21, 2012 by BLAST FROM THE PAST

[picog]

Great output again this morning. Both GFS and ECM going for some very cold options but down different routes. Personally, I like the ECM as it builds a nice Greenland High with a Northerly by the end of the run. The next few frames would of been good!

Just for some fun this morning aswell, latest CFS temperatures for next 4 weeks. That is one cold December.

The profile looks very Dec 2010 to me — temperatures typically shooting up just as the festive season begins!

[SMU]

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

A few more stella runs creeping in now - ( also a few milder ones- but hey who wants to discuss them)

Sub zero maxima & SNOW- these are 100% allowing the russian air to get over to holland- like the control run for example.

Fingers crossed.

It also highlights the fact that the ECM OP's ( like yesterday remember them being discarded) could be a slight outlier- which I 100% remember happening in Nov 10 when the ensemble pack was solid.

S

Edited November 21, 2012 by Steve Murr

[SMU]

The profile looks very Dec 2010 to me — temperatures typically shooting up just as the festive season begins!

IF THE CFS is to be belived that ~ 17 days on the bounce- 8th to the 25th with no temp above freezing- that would be jan 47 territoryS

[BLAST FROM THE PAST]

The profile looks very Dec 2010 to me — temperatures typically shooting up just as the festive season begins!

That is extreme, way too extreme IMO and I'll ramp with the best of them

BFTP

[Nick F]

Good agreement from this morning's operationals on the overall 500mb pattern in the 8-10 period, with the +ve heights over Iceland and -ve heights to the SE of the UK. 00z ECM has quite a notable arctic high which would further re-inforce northerly blocking and allow any cold flow to be locked in:

http://www.meteo.psu...0z/hgtcomp.html

However, some quite large differences between the models at the surface as early as this weekend, note ECM has a deep low crossing Sern Britain early Sunday, GFS doesn't:

And these surface differences continue into next week, which will have an effect on how the cold air sinking south and southwest is distributed.

Edited November 21, 2012 by Nick F

[No Balls Like Snow Balls]

The T120 time frame hasn't been agreed on yet between the big 3 models with the ECM wanting to place LP West of the UK and bring us milder air in the mid term - therefore until that is sorted I refuse to get excited about "carslberg" runs in FI.

I know that the ECM op was a outlier but that doesn't mean to say that the ensembles won't come into line with the op rather than vice versa. Just trying to keep a level head and keep things in perspective.

[legritter]

Looking at this mornings runs as certainly filled my glass ,i would say some almost perfect synoptics on offer .but caution still needed .if next weeks modelled charts arrive and keep going into December it would be a good call from the met office ,perhaps we are starting to get to grip with the generall weather pattern out in the 2/3week period with all our massive computers and upper air data ,but the other part of the puzzle is hard because everyone is looking for so much detail .also plenty of posters on this forum have called a good call .thanks again to all the technical posters .i think we are starting to see around that meteorological Corner .cheers

[Dexter29]

The T120 time frame hasn't been agreed on yet between the big 3 models with the ECM wanting to place LP West of the UK and bring us milder air in the mid term - therefore until that is sorted I refuse to get excited about "carslberg" runs in FI.

I know that the ECM op was a outlier but that doesn't mean to say that the ensembles won't come into line with the op rather than vice versa. Just trying to keep a level head and keep things in perspective.

Wise words, the ECM has a dartboard low crossing Southern Britain on Sunday. GFS is showing nothing.

If the models can't even agree on this weekends developments I remain to keep a realistic head on and remember these cold charts that are showing are FI and IMO are just for fun at the moment, because things will almost 100% change come the end of the month. Good or bad.

Still great to read the more experienced posts though, always excellent!

[carinthian]

Good Morning,

Just got our latest snow prediction and forecast for the start of the season here on 1st December. Makes interesting reading, particularly regarding where the deepest cold is expected in 10 days time. Basically, watch out SE Britiain, the Low countries and Northern Germany at the turn of this month. Still not good news yet here in resort, but hopefully we should soon see some snowfall at 1000m.

C

[sebastiaan1973]

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/ 168h individual members

[SMU]

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=code&mode=0&mode3h=0&runpara=0&carte=1

for ONCE in a lifetime the 06z looks like the UKMO at 144-

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=code&mode=0&mode3h=0&runpara=0&carte=1

Could be a crackerjack run & the ONLy reason im viewing is because it looks like the euro!

S

[nick sussex]

I think theres a slightly better chance of getting some colder uppers into the UK before any retrogression and this is in relation to the Arctic high ridging south.

As this does so it could pull a finger of colder air sw and this could get redirected into the UK, much depends on how quickly the retrogression takes place if it does indeed verify.

[No Balls Like Snow Balls]

http://www.meteociel...npara=0&carte=1

for ONCE in a lifetime the 06z looks like the UKMO at 144-

http://www.meteociel...npara=0&carte=1

Could be a crackerjack run & the ONLy reason im viewing is because it looks like the euro!

S

Obviously you won't believe a word of what it's showing though LOL

Edited November 21, 2012 by No balls like Snow Balls

[Nick F]

Good Morning,

Just got our latest snow prediction and forecast for the start of the season here on 1st December. Makes interesting reading, particularly regarding where the deepest cold is expected in 10 days time. Basically, watch out SE Britiain, the Low countries and Northern Germany at the turn of this month. Still not good news yet here in resort, but hopefully we should soon see some snowfall at 1000m.

C

Morning C, I'm sure your little ramp will be well received in my part of the world!

I guess the eventual position of the low over mainland Europe will mean that milder air will be dragged up from SE Europe over your locale and the coldest air will move southwest further north over Nern Europe, but I'm sure once the low sinks, you may tap into some colder air from the NE across Austria.

Edited November 21, 2012 by Nick F

[MKN]

You can't bin a run just because its less reliable. It just means it has less chance of verifying. Not no chance. And you have to remember the data fed into it includes 6 hours of new data the previous run didn't which could be crucial further down the line. That's not to say I,LL take anything past 144 as having even half a chance of being correct.

[Cloud 10]

As Steve also said earlier: BIN the 06Z

What he meant was Buy It Now...