Model Output Discussion 18th Nov.2013-12z onwards.

[Ian Brown]

NO.

 

The ECM did polar blocking for 2 runs & gave it up before it found the right pattern. This was to do with the path of the tropical storm.

 

The GFS goes for the zonal reset every time, that means occasionally it will seem correct when in fact its just forecasting persistence.

 

S

 

That's summary is too simplistic Steve, yes the GFS is often keen to barrel the jet thru at Northern latitudes but when blocking is involved they can all struggle at times - don't forget the ECM has shown easterlies at T120 that haven't come off.

[Summer Sun]

@Glenn W

 

GEM only goes to t240

 

GFS ensembles shows the 850's recovering around the 9th coldest period looks to be later next week

 

Edited November 29, 2013 by Summer Sun

[Whether Idle]

, there is a 168hrs but for some reason the UKMO view this as top secret, apparently its under armed guard 24hrs a day in case God forbid a member of the public could actually view it!!!

 

I see why - it keeps the product as one of relative quality and accuracy, avoiding much of the FI pfaffing.  That's not to say the Met O is always accurate - I think it verifies at 144 usually in second place; though by virtue of its short time period it avoids the same number of reversals the longer reaching models inevitably suffer from.

[Mucka]

That's summary is too simplistic Steve, yes the GFS is often keen to barrel the jet thru at Northern latitudes but when blocking is involved they can all struggle at times - don't forget the ECM has shown easterlies at T120 that haven't come off.

 

 

GFS 12z ensembles, as has been said it is all about the modelling upstream. I always say take in as much data as you can and try to avoid confirmation bias re the models but on this occasion I agree it makes sense to stick with the Euros until there is cross model support - that doesn't mean they will win the race but they are favourites in this situation. 

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=256&y=98

 

These ensembles could look very different tomorrow.

Edited November 29, 2013 by Mucka

[R.P. McMurphy]

Only goes to t240

Ah...Apoligies, Just noticed you put up the GEM... Allow me...

 

[The Northern Ramper]

Where is the rest? Where it shows a full reload and any "warmer" (If you can call it that) air is removed and an attack from the NW resumes....

It doesn't suit his agenda Glenn.Ukmo looking on the money tonight, I would bet the ECM will follow suit.

[Cloud 10]

12z UKMO and GFS at 120 hrs.

 

GFS..  UKMO..

 

 

The gfs still has the spoiler LP whereas the UKMO has not which allows

for a much cleaner northerly later on.

 

Look for this feature (or lack of it) on the ecm in the next 15 minutes.

[nick sussex]

I see why - it keeps the product as one of relative quality and accuracy, avoiding much of the FI pfaffing.  That's not to say the Met O is always accurate - I think it verifies at 144 usually in second place; though by virtue of its short time period it avoids the same number of reversals the longer reaching models inevitably suffer from.

Regarding the 168hrs output, I don't see why they can't just release it, economically this isn't a big deal for them , its not like we're asking to see the MOGREPS. I understand they need to bring in external funding but a lot of that is with longer range forecasts for business etc, another 24hrs of data made available to the general public is hardly going to sink them. And the only people that will view it is model anoraks like us, its not like Britney is going to get all upset because the 168hrs was a bit dodgy, I can see it now, traumatized Chav seeks damages from UKMO after erroneous 168hrs  output!!!

[SMU]

GFS consistency I hear you say?

 

from 00z last night 192 - to the SAME chart 12z today 156 - that's 6 runs -

 

00z 192

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112800-0-192.png?0   Northerly with some blocking to the NW

Midwest low through the middle- No Canadian ridge   7/10

 

06z  186

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112806-0-186.png?6   No Northerly- timing slower some blocking to the NW - Midwest low through the middle 6/10

 

12z  180

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112812-0-180.png?12  What the ACTUAL? No low phasing, no Northerly & America no signal whatsoever 3/10

 

18z 174

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112818-0-174.png?18  No Northerly AGAIN- No low phasing & America no Signal whatsoever   4/10

 

00z  168

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112900-0-168.png?0  Northerly Scraping the East of the UK & no blocking still evident over by the PNA area- Midwest low still going through 5/10

 

06z 162

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112906-0-162.png?6  BEST RUN SO FAR? NB: low phases correctly & the Midwest low is SLOW as the PNA block is ridging over the top ( note the colder run to the end)   8/10

 

12z 156 - Todays RUN

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2013112912-0-156.png?12  Backs up the 06z on the Northerly but the 12z on the weakest statistical run for accuracy of the PNA shows a bowling ball low through again over the Midwest-  6/10

 

 

I will keep updating this post-

 

ECM runs for the same time frame

 

00z 192

http://www.meteociel.fr/modeles/ecmwf/archives/2013112800/ECH1-192.GIF?00  Northerly is Strong, Midwest low stuck under the ridging- Interesting amplifaction in atlantic- shortwave moving into Greenland   7/10

 

12z 192

http://www.meteociel.fr/modeles/ecmwf/archives/2013112812/ECH1-192.GIF?12  Northerly Strong, Midwest low blocked & slow

Shortwave not amplified to Greenland but recurving SE around the block -   9/10   *******

 

00z 168

http://www.meteociel.fr/modeles/ecmwf/archives/2013112900/ECH1-168.GIF?00  Northerly Strong, Midwest low blocked & slow

Shortwave back aimed at Greenland 7/10

 

 

So much more consistency from the the ECM-

 

Where will the shortwave go??? Recurving SE would be the form horse!

 

S

Edited November 29, 2013 by Steve Murr

[bluearmy]

 

Ah...Apoligies, Just noticed you put up the GEM... Allow me...

 

 

But thats the end of gfs at day 16, not the gem at day 10 ?????? why would gavibn post the gfs when he is showing us the gem ?

[R.P. McMurphy]

   But thats the end of gfs at day 16, not the gem at day 10 ?????? why would gavibn post the gfs when he is showing us the gem ?

If you read my post, it was to show a reload from the NW after some cold HP moves over? Can't show that on the GEM as it only goes out to T240.

[Panayiotis]

NO spoiler low on the ECM at 120hrs and also notice the strength of the PV on the GFS compared to the other two models @Cloud10 looking good and very similar to the UKMO.....

Edited November 29, 2013 by Panayiotis

[Summer Sun]

Here comes the colder air

 

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013112912/ECH1-144.GIF?29-0

 

Northerly on its way-

 

Looks like ECM is going 3/4 runs with that shortwave moving into Greenland...... Not sure....

 

Note the Midwest low SLOW under the 1045 high....

 

S

Edited November 29, 2013 by Steve Murr

[Cloud 10]

Cracking northerly incoming on the 12z ECM.

 

 

[Snowman.]

[No Balls Like Snow Balls]

ECM T168 is a beast of a chart for cold air flooding south

[Mark Neal.]

Cold Uppers head south at 168hrs..

 

[terrier]

Scotland would certainly get some problematic snowfall from tonight's ECM

[Skyraker]

Ensemble watch.

 

[Stuie]

Well I think the first real chill is definitely coming, how long is probably FI.

[Joe Levy]

A lovely cold northerly with -6 uppers covering the whole country and -8 uppers just touching the south coast. This is exactly the sort of chart us coldies have been hoping to see maintained in the charts

[Panayiotis]

THIS IS COLD brrr!! Heavy snow showers moving in a strong to moderate NW wind....

Edited November 29, 2013 by Panayiotis

[I remember Atlantic 252]

is a good chart at 168, -8 uppers maybe enough for showers to come in off the warm Irish sea, into low levels in Midlands

 

cracking run for those mainly in NW areas and obviously Scotland

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013112912/ECH1-168.GIF?29-0

Day 2 of the cold

 

Sees polar low over Iceland & the -8c line into the South

-12c into Scotland

 

http://www.meteociel.fr/modeles/ecmwf/runs/2013112912/ECM0-168.GIF?29-0   -14c into Shetland!!!!!!!!!!!!

 

http://www.meteociel.fr/modeles/ecmwf/runs/2013112912/ECF0-168.GIF?29-0

 

S