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

[Frosty.]

But OP is run at higher res than mean? A lot to go through and more ups and downs I think through DecemberBFTP

Yes but the trend has been to turn cold and unsettled, so the gfs 12z op can probably be treated with the contempt it deserves. Edited November 28, 2013 by Frosty.

[Captain Shortwave]

 

#

Probably the craziest member, but plenty of perturbations showing a northerly between days 8-10. The op looks to be in the milder cluster of solutions. Big range of solutions though. Going to be a bumpy ride.

The control run shows this, not as extreme but still pretty stormy

There is a brief cold (snow) window as this clears so better than the op.

It does show a Scandi high though

Edited November 28, 2013 by Captain shortwave

[IDO]

The GFS 06z ens were split 50/50 Atlantic ridge or not. The 12z Control says yes to the ridge:

T192: T240:

T300:

The short ens hint the op may be a pressure outlier:

Edited November 28, 2013 by i'm dreaming of...

[The PIT]

It will be interesting to compare the ECM and UKMO at T144. Bit of difference between the GFS at the UKMO at this time. I wouldn't be surprised if the ECM pushes everything slightly further east than the GFS shows.

[nick sussex]

The mild operative who placed a bug in the GFS computer be warned we will find you! Jeez that GFS operational run certainly harpooned the festive spirit! There's some strange goings on upstream between this run and the earlier 06 and 00hrs run, it speeds that shortwave through the USA  very quickly and flattens the downstream ridge which flies in the face of what NOAA think is going to happen.

 

The UKMO is a chasm away from the GFS upstream so its all very uncertain, regardless of what the ECM shows I think we'll have to wait till tomorrow as its hard to have a lot of confidence if the big 3 don't agree at 144hrs.

[radiohead]

Yes, ensembles for northern Scotland show the 12Z GFS op as a clear outlier at T180.

 

[bluearmy]

the gefs in week 2 are not without interest - do they reveal the next stage of this winters model watching travails - scandi high and cold pool stuck below ????? not sure many of us will make it to january at this rate !!

[stodge]

One thing I'm looking at in the short term is whether the HP will be positioned to introduce a continental feed to southern and southeastern parts.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2013112812/gfs-0-96.png?12?12

 

Hints of an ESE'ly drift - could be quite cold and potentially foggy.

[IDO]

GEFS 2m Temp:

As others suggested this is the mild outlier to balance the cold 0z. Ignore till it garners more support.

I think it goes wrong by pushing the Pacific Trough quickly east thru the US, so any short wave coming off the east coast is bustled along not allowing time for it to take the cold route.

Edited November 28, 2013 by i'm dreaming of...

[MR EXTREMES]

there is the option that steve murr pointed out a couple of days ago scandi heights have been a feature for most winters recently so never can rule scandi heights out atleast if we can see one of these features move closer into a more realistic timeframe then anything is possible other than 2009 and 2010 the scandi heights have brought us some snowy weather here in the south of uk.

 

so I wonder will it wont it im not convinced of anything and wont be until the end of the weekend.

[arni]

Seems like GFS op was a cold outlier in the 6z and is now a mild outlier in the 12z.

UKMO a bit better than GFS at 144. I think that gfs doesnt deal very well with that low exiting the US at t144.

 

Hopefully ECM tonight will join UKMO at 144 !

[nick sussex]

This is the latest NOAA update, if the GFS is right then this will need a hasty re-write. They do though highlight uncertainty later although were happy to go with the ECM 00hrs output.

 

A BROAD-SCALE TROUGH WILL PREVAIL ACROSS THE LOWER 48 DURING THISMEDIUM RANGE PERIOD--CHARACTERIZED BY AN ARCTIC INTRUSION--COUPLEDWITH A SIGNIFICANT UPPER-LEVEL SYSTEM MIGRATING ACROSS THE PACIFICNORTHWEST-NORTHERN ROCKIES THROUGH DAY 6 (WEDNESDAY)...AND THENORTH CENTRAL PLAINS DAY 7 (THURSDAY). DOWNSTREAM FROM THE RIOGRANDE VALLEY EASTWARD TO THE SOUTHEAST COAST...THE FORECAST WILLBECOME A CHALLENGE (MONDAY AND TUESDAY) AS THE BASE OF THIS BROADUPPER-LEVEL TROUGH BECOMES ENTRAINED WITH CONFLUENT SOUTHERNSTREAM FLOW AND EMBEDDED ENERGY ORIGINATING IN BAJA CALIFORNIA ANDTHE GULF OF MEXICO....PREFERENCES...THE 28/00Z ECMWF SOLUTION WAS THE MODEL OF CHOICE TODAY...WITH THE28/00Z NAEFS/EC ENSEMBLE MEANS IN GOOD SUPPORT OF A DIGGING...ANDDEEPENING COLD POOL/UPPER-LEVEL TROUGH IN THE GREAT BASIN FROM DAY5 ONWARD...AND A COASTAL WAVE DEVELOPING OFF THE SOUTHEAST COAST. 

At day 7 the GFS is not on the same planet as the expected pattern, the digging trough leads to high pressure further east, the GFS shows a shortwave near Quebec and the ridge flattened.

 

The UKMO is pretty close to NOAAs current thinking, at this time the GFS operational run looks like a SSO Suspicious Synoptic Outcome and for the timebeing looks very unlikely to verify.

[Ian Brown]

The GFS is always one extreme to the other and ultimately this is still beyond day 7 (T168) on the models so let's see what subsequent runs bring.

[SMU]

Yes, ensembles for northern Scotland show the 12Z GFS op as a clear outlier at T180.

 

 

 

Good post Radio head-

 

anyone doing the ensemble watch- its around 8 for the 12z.

 

S

[Skyraker]

I'll do it if it will shut you up

 

Good post Radio head-

 

anyone doing the ensemble watch- its around 8 for the 12z.

 

S

[Barry12]

Lets compare the ECM with GFS

 

[SMU]

I'll do it if it will shut you up

 

Thanks

 

Its for the newbies mainly....

 

Look forward to it.!

[MR EXTREMES]

intresting ecm at t120 where do we go from here could be a nightmare or could be a euphoric dream Jessica alba type

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013112812/ECH0-120.GIF?28-0

 

ECM 120- The cold just 5 days away now...

 

S

[SHM040519]

http://images.meteociel.fr/im/1798/ECM1-144_mtn3.GIF

 

ECM 144hrs 

[MR EXTREMES]

t144 not much of a negative tilt on the high pressure to the west but what I like is there is a margin of area so could get better in future runs although still only t144 fingers crossed we now need a nice south or se track of this low pressure system.

 

BIG IF because this to looks like a near miss if this is then I feel all models are singing for the same sort of hyme sheet which is not good news.

Edited November 28, 2013 by emotional rollercoaster

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013112812/ECH1-144.GIF?28-0

 

144

 

Canadian high ridging East - CHECK

Atlantic High- CHECK

Shallow East coast low - CHECK

Small energy to southern Greenland- CHECK

 

COLD coming 168? CHECK

[nick sussex]

The NetWeather trauma unit is ready and raring to go in the event of further model turmoil! The ECM looks nothing like the GFS at T144hrs which is a relief, but we're not out of the woods yet, the real interest doesn't come till outside of 144hrs.

[Matty M]

ECMWF best of the bunch at 144hrs.

 

So be interesting to see how it develops post 144hrs..

[Panayiotis]

Comparison between GFS and ECM 144hrs and well the ECM is looking much better with the low leaving the US on a much more southerly track and has a slight negative tilt to it compared to the GFS (which looking at the ensembles seems to be an outlier); positive signs!

Edited November 28, 2013 by Panayiotis