Model Output Discussion - 14th Jan 12z Onwards

[snowy weather]

UKMO @144 dropping South East and filling!

What does this mean please?

is it good for SE?

Edited January 15, 2015 by snowy weather

[shaky]

Jesus some parts of the uk COULD be buried next week especially if the ukmo verified!!

[MR EXTREMES]

UKMO at 120

Vs GFS @ 120

Well well gfs stats are TOP ATM second ecm and third ukmo so two out of 3 ain't bad what with these two charts identical and the alantic blocked pretty good so far Edited January 15, 2015 by emotional rollercoaster

[frosty ground]

Looks like the UKM and GFS have changed postions.... UKM now has a deeper low with while the GFs has a shallow low.

[swfc]

Must be me but im seeing the 12z as a poorer run than the 6z?Easterly incoming looks a short lived affair and heights to the north east look much flatter with low pressure over the top!Ok run but on the nhp it is poorer imo

[Neilsouth]

Jesus some parts of the uk COULD be buried next week especially if the ukmo verified!!

 

Doubtful... I expect people are seeing blue too much.

 

This really depends on what this low pressure system does, we have been here many many times before and the direction hardly ever favours the uk except in rare occasions

[karlos1983]

Am I right in thinking the GFS is looking better??? if im wrong could somebody explain for me please??

 

I'm not convinced

[fergieweather]

The key difference with 12z GFS versus it's preceding run is the modelling of a closed circulation and moreover, running this further south. Despite the initial awkward and finely balanced forecast rain-sleet-snow phase in much of south, this current prognosis would then readily entrain colder boundary layer around N-NW flank and - depending on how this phases with occlusion remnants/forcing/WBFL - would readily give snow for a while as the centre moves S. However, it duplicates various earlier ENS members so albeit a plausible outcome, remains but one of many - some more nuanced than others.

[karlos1983]

Must be me but im seeing the 12z as a poorer run than the 6z?Easterly incoming looks a short lived affair and heights to the north east look much flatter with low pressure over the top!Ok run but on the nhp it is poorer imo

 

Exactly what I was thinking. Looks to me like that high will sink surely?

[nick sussex]

I'm not convinced

The UKMO is better going forward because its split the PV to the north, as long as the low heads se the UKMO would go onto deliver a better outlook.

[terrier]

Must admit I'm with Karlos and swfc here. The gfs 12z just looks wrong short lived easterly then the high just sinks. Not a great outlook that from gfs. Much prefer the ukmo solution this evening. Let's see what ECM does later on.

[Dr. Astro]

The key difference with 12z GFS versus it's preceding run is the modelling of a closed circulation and moreover, running this further south. Despite the initial awkward and finely balanced forecast rain-sleet-snow phase in much of south, this current prognosis would then readily entrain colder boundary layer around N-NW flank and - depending on how this phases with occlusion remnants/forcing/WBFL - would readily give snow for a while as the centre moves S. However, it duplicates various earlier ENS members so albeit a plausible outcome, remains but one of many - some more nuanced than others.

 

Thanks Ian for your input, a little bit more of a headache for Exeter then wrt differentiating solutions across the board.

[swfc]

Exactly what I was thinking. Looks to me like that high will sink surely?

look at 12z 174 hr chart and compair to the 6z,chalk and cheese and much lower heigths into scan.Snow there know doubt but much flatter from here on in

[phil nw.]

Before we get to next week GFS shows around Sat pm snowfall across large areas of England and Wales.

 

 

pulses of colder air moving in from the north west with minor troughs embedded in the flow probably snow showers merging i would think.

[Captain Shortwave]

GFS is okay to me, reasonable snow event for many, 24-36h north easterly with 850s dropping to -8/9C, should get at least a dusting in eastern areas from this convective period. Beyond that it looks like a UK high set up so remaining very cold at the surface under clear skies.

 

Personally I'm unconvinced of the Greenland polar vortex comeback to me.

UKMO, again if only we could see the 850s and locate where the warm sector is, the progression of the low is a lot slower so I guess many eastern areas could remain very cold and mostly dry until Wednesday (if the front even arrives of course).

Edited January 15, 2015 by Captain shortwave

[Downpour]

Both runs are very nice for prospects in the shorter term. Exeter is the choice of the connoisseurs who seek a classic cold spell rather just than a quick dump and deliver. 

 

I haven't seen a flake for near two years so I'd take either!!

[frosty ground]

Must admit I'm with Karlos and swfc here. The gfs 12z just looks wrong short lived easterly then the high just sinks. Not a great outlook that from gfs. Much prefer the ukmo solution this evening. Let's see what ECM does later on.

Yep....... And the UKM is not that great either (for the south at least)

[SMU]

The key difference with 12z GFS versus it's preceding run is the modelling of a closed circulation and moreover, running this further south. Despite the initial awkward and finely balanced forecast rain-sleet-snow phase in much of south, this current prognosis would then readily entrain colder boundary layer around N-NW flank and - depending on how this phases with occlusion remnants/forcing/WBFL - would readily give snow for a while as the centre moves S. However, it duplicates various earlier ENS members so albeit a plausible outcome, remains but one of many - some more nuanced than others.

#

 

Yes we expected this-

 

 

& the UKMO 144 sees a large scale snow event with a southerly draw out of the continent with minimal warmer air entrapment-  UKMO must be concerned at that-

 

Thickness over London on the 995 contour is about about 529 DAM reducing to 525 ish towards the midlands & wales.

 

http://www.meteociel.fr/ukmo/run/U144-21UK.GIF?15-17

 

S

Edited January 15, 2015 by Steve Murr

[bluearmy]

Looking at the uk map on meteociel, the Ukmo looks quite snowy away from cornwall and w Devon with a se surface flow ahead of the occlusion.

Looks like a cleaner demarcation between the snow and not snow though clearly too far away for detail.

Edited January 15, 2015 by bluearmy

[IDO]

Must admit I'm with Karlos and swfc here. The gfs 12z just looks wrong short lived easterly then the high just sinks. Not a great outlook that from gfs. Much prefer the ukmo solution this evening. Let's see what ECM does later on.

 

Yes there was a 28% clustering for a fast track easterly on the 06z GEFS and all pretty much sunk the high, with the Atlantic back in by D10. I would have thought that we would want the slower 06z op run to give heights a chance to build. 

[Mucka]

Yes GFS has a lot more energy pushing through Greenland area than initially looked credible from the 120 chart so the ridge topples quickly to a lower latitude.

Just another run and another outcome, all part of the fun of model watching.

[Barry12]

Not a great outlook that from gfs. Much prefer the ukmo solution this evening. Let's see what ECM does later on.

 

The GFS has 8 days with cold and snow, how is that not a great outlook? Think your expectations are a little to high.

[karlos1983]

the ship is sinking, much preferred the 06z version.

it sure won't be warm though 

Edited January 15, 2015 by karlos1983

[polar vortex]

As others have said amazing how the heights to the north on the gfs have all but gone by t144 where as 

the ukmo akin to chalk and cheese with much better heights and almost certainly adding longevity to the 

cold spell.

[Mark Bayley]

Before we get to next week GFS shows around Sat pm snowfall across large areas of England and Wales.

 

gfs-2-54.png

 

pulses of colder air moving in from the north west with minor troughs embedded in the flow probably snow showers merging i would think.

 

Agreed, many snow chances even before any potential easterly. I'm with Steve in that Tuesdays precipitation is likely to be further west than most are hoping (i.e. i'd not expect much east of the Pennines/East Midlands). Wales will most likely do very well. In the mean time many disturbances will likely give snow to those that may not benefit from Tuesdays more organised precipitation. This is before any potential easterly. The GFS makes more of the PV over Greenland, so UKMO better for longer term prospects. I'd hazard a guess that the GFS is way to quick in sinking heights to the NE.