Model Output Discussion - Stormy Period Inbound...

[Ali1977]

Errrr  - Where has the Easterly gone..............Never thought it would be gone that quick, hopefully the ENS prove this to be an outlier.

Edited January 13, 2015 by Ali1977

[Mucka]

And UKMO

 

 

We need ECM to keep the faith. This rollercoaster has just begun.

 

I reckon GFS Op will be a big fat mild outlier (well little support at least) day 9/10 re 850's. Definitely not time to panic yet - there will be plenty of time for that tomorrow!

Edited January 13, 2015 by Mucka

[SMU]

Well the GFS 12z non P has shown its progressive nature- the Angle of the slider & the blocking to the NE not as good, where as the UKMO 120 is perfect - similar to the ECM 00z

 

http://www.meteociel.fr/ukmo/runs/2015011312/UW120-21.GIF?13-17  I would suggest that's -6c clearing the south coast, the -8c line moving south & -10c in Scotland.

 

then, well ER.

 

http://www.meteociel.fr/ukmo/runs/2015011312/UN144-21.GIF?13-17

Deep surface cold widespread ( sub -15c overnight minima in Scotty ) & WIDESPREAD below freezing maxima with snow arriving.

http://www.meteociel.fr/ukmo/run/U144-21UK.GIF?13-17

 

SOOO much better than the GFS

Edited January 13, 2015 by Steve Murr

[winterof79]

Lets see if the GEFS have the low off the Eastern Sea Board that has sprung up from nowhere

http://modeles.meteociel.fr/modeles/gfs/runs/2015011312/gfsnh-0-162.png?12

A lot  more Eastward movement up to our north west with the aid of that.

[IDO]

Phantom height rises, the curse of computer generated models when there is something complicated as cyclogenesis, and in this period we have two systems, so it is no surprise FI is D5-6.  We just have to wait for the models to resolve how they interact with the current pattern.

 

The GEFS from the 06z at D9 had the main cluster, 45%, in line with the 12z: 

 

So it is no surprise that the op would trend that way, though that is not to say it is right, just more likely until the correct signal is picked up.

[Cheshire Freeze]

Well the GFS 12z non P has shown its progressive nature- the Angle of the slider & the blocking to the NE not as good, where as the UKMO 120 is perfect - similar to the ECM 00z

 

http://www.meteociel.fr/ukmo/runs/2015011312/UW120-21.GIF?13-17  I would suggest that's -6c clearing the south coast, the -8c line moving south & -10c in Scotland.

 

then, well ER.

 

http://www.meteociel.fr/ukmo/runs/2015011312/UN144-21.GIF?13-17

Deep surface cold widespread ( sub -15c overnight minima in Scotty ) & WIDESPREAD below freezing maxima with snow arriving.

http://www.meteociel.fr/ukmo/run/U144-21UK.GIF?13-17

 

SOOO much better than the GFS

 

UKMO is COLD going forward but the 12z GFS is horrid....the day 10 chart is stuff of nightmares.

[Ali1977]

Surely the GFS must be wrong, the PV is raging over Greenland by day 9.....I hope the ECM doesn't follow it as this place will be very depressing if so. GEFS will be eagerly awaited.  The GEM looks good to T108.

Its times like these when it is good to have the METO on board (a little)

Edited January 13, 2015 by Ali1977

[SMU]

Just to add the NAVGEM is pretty similar to alignment at 144 - look at the evolution.

 

http://www.meteociel.fr/modeles/navgeme_cartes.php?ech=6&code=0&mode=0&carte=1&archive=0

 

the GFS 12z looks very unlikely

S

[Nick F]

Here's my latest synoptic outlook - focusing on risk of snow this evening, overnight and Wednesday morning. Then a rapidly deepening low, storm Rachel, bringing severe gales and heavy rain across the UK Wednesday night and Thursday morning.

 

http://www.netweather.tv/index.cgi?action=news;storyid=6400;sess=

[IDO]

GFSP was keen on +AO for sometime but now latest update shows -AO according to Ryan Maue.

 

That was based on one run and *if* it was an outlier then the trend is for the AO to just dip negative before returning positive:

 

  RyanMaue

GFS parallel over past several days was insistent on developing strongly positive AO ... not so much anymore http://t.co/Kpzt4HsrXl

13/01/2015 15:54

 

Yes the GFS FI FWIW is a poor synoptic as we head into Feb: 

[West is Best]

6z parallel is nothing short of SENSATIONAL..it's yet another upgrade on the wintry theme of earlier output, a significantly upgraded Northerly with -10 T850 hPa flooding south. We have Northerlies and Easterlies on this run, it's almost perfect in my opinion and an enormous improvement from last winters and early this winters Atlantic dross...mild sectors are snuffed out which is great news for coldies...I'm looking forward to the snow, ice and a sharp frosts during the weeks ahead.

 

Bloody hell. I just got back in and saw the 6z GFSP. That is one of the greatest runs I think I've seen: one of those once-in-a-winter runs which stacks up the cold. Incredible upper temps.

 

Now back to reality. The 12z GFSO (are we allowed to call it that i.e. operational to compare with GFSP?) is a return to zonality. It'll be interesting to see if and how many of the ensemble members, as well as GFSP, go with GFSO and then to compare those with UKMO / ECM. Something fishy's in the air, and I'm not referring to the contents of Baldrick's apple crumble.

Edited January 13, 2015 by West is Best

[Mucka]

GEM looking a little better than this morning so far, complete with channel low.

 

 

I will be surprised if GFS op isn't very much on the milder side of its ensembles past day 7/8

Edited January 13, 2015 by Mucka

[Hotspur62]

Just to add the NAVGEM is pretty similar to alignment at 144 - look at the evolution.

 

http://www.meteociel.fr/modeles/navgeme_cartes.php?ech=6&code=0&mode=0&carte=1&archive=0

 

the GFS 12z looks very unlikely

S

Hope you are right about that and GFS wrong.Its amazing that when a cold spell is on offer we never seem to get agreement across the board with the models.It would be nice to put your feet up knowing the cold would definetly come but never works like that for the UK when cold is imminent  

[SMU]

That was based on one run and *if* it was an outlier then the trend is for the AO to just dip negative before returning positive:

 

  RyanMaue

GFS parallel over past several days was insistent on developing strongly positive AO ... not so much anymore http://t.co/Kpzt4HsrXl

13/01/2015 15:54

 

Yes the GFS FI FWIW is a poor synoptic as we head into Feb: gfsnh-0-372 (3).png

 

Lol IDO , 15 day 12z GFS.

 

Only yesterday you were touting the 15 day Mean saying it was all going to be zonal.

 

Why don't you look in the real time window? as opposed to a pointless timeline 15 days away...

[IDO]

The GEM at T114 is still sending that low (second one) across the Channel. Even UKMO has dumped that track now:  

 

 

Anything that follows should be discarded if we do not see this as the correct route.

[Ali1977]

GEM is going to be V good...Slider next Mon+Tue followed bt a Beast....I think

[Cheshire Freeze]

GEM looking a little better than this morning so far, complete with channel low.

 

 

I will be surprised if GFS op isn't very much on the milder side of its ensembles past day 7/8

 

GEM looks good at 132...miles better than the GFS

 

 

Even better going forward

 

Edited January 13, 2015 by CreweCold

[Ali1977]

GEM looks good at 132...miles better than the GFS

 

 

Even better going forward

 

Looks good but no cold uppers which is a bit strange.

[bluearmy]

Are we really looking at low resolution Gfs against it and all the other ens guidance at that timeframe.

Bin the run post T192 and once all the other output and GEFS are out, probably post day 6.

Crewe - gem uppers don't verify cold enough unless the flow is continental.

Edited January 13, 2015 by bluearmy

[Cheshire Freeze]

Looks good but no cold uppers which is a bit strange.

 

Yes there's almost certainly an error with the uppers

 

In the short term, the GFS control really ramps up the winds across N Midlands and N England RE Wednesday/Thursday storm

 

Edited January 13, 2015 by CreweCold

[Mucka]

Looks good but no cold uppers which is a bit strange.

 

They are broken along with ppn, ignore uppers on GEM output they are always overdone. 

[mushymanrob]

not sure why there should be so much discrepancy between the gfs and gfsp... nor why the gfs 12z is likely to be inaccurate. it might be on the ball... although a cold spell is likely, its not a cert or at least a big freeze isnt.

[SMU]

The GFS mean at 72 is slightly more amplified that the 06z.

 

http://modeles.meteociel.fr/modeles/gens/runs/2015011312/gensnh-21-1-72.png

 

In terms of a cold snap from T72- 144 we are more or less home & dry, post that not quite yet.

 

Even the 12z GFS however had solid cold for 5 days....

 

S

[Hotspur62]

Well in reliable timeframe upto T144 its GEM,ECM,UKMO v GFS.Was it the GEM that first showed an Easterly 2/3 days ago before any other models??Would love that GEM to verify at 168 but too far out in FI!!

[Mucka]

not sure why there should be so much discrepancy between the gfs and gfsp... nor why the gfs 12z is likely to be inaccurate. it might be on the ball... although a cold spell is likely, its not a cert or at least a big freeze isnt.

 

That is why we have ensembles and other models to cross reference with to determine probability of outcome mushy.

We will have a better idea once the ensembles are out but certainly a prolonged cold spell is very much in the balance.