Model Output Discussion 29th December - Into mid-Winter.

[Nimbus Nix]

Having an early look at the 12z NAM, it seems to be much closer to the ECM off SW Greenland than the GFS 6z. The shortwave running through E Canada is possibly even better than the ECM, helping to slow the trough down as it enters the Atlantic:

Early days though, we'll see if the 12z GFS follows the trend.

[Dennis]

Hope that ridge will be strong......for a nice polar dive

Edited January 9, 2017 by Dennis

[Hotspur62]

Before the 12z GFS rolls out i just thought i would put my 2 bobs worth in.Firstly, i would like to note that i have the utmost respect for the likes of SM,JH,Tamara,Mucka etc etc and they will always have more knowledge and expertise than me and although they see things from different perspectives on occasions they are entitled to their opinions be it on the Models or teleconnections front etc.Thats what makes this forum the best there is as it is always helping the less knowledgable like yours truly to learn..

Last night was fascinating watching the Models roll out and i Found SMs comment interesting regarding the GFS slowly come into line for the reasons he explained.This has indeed happened to a degree but whether or not there is enough amplification down the line is still to be seen but the one thing i remember him saying the other day is never doubt the UKMET model and for this reason i just feel that now we are in T144 it is clear that the NW of UK could fayre well come Thursday and Friday and i keep my fingers crossed for them that some beefy snow showers turn the landscape that magical white colour.Those Midlands Southwards are imho unlikely to see this happen as history tells me on a NW flow we will just be cold and bright with showers fading as they move SE.The more interesting time to look at is from Sunday onwards and whether we can get the ridge moving towards Scandy and thus developing a Continental flow(as SM was expaining last night).Again, i think the chances of this are slim(20% at most) which sort of ties in with Met Office but it would be nice that just for once in about the last 4 years the "outside" bet can come in and will reap the dividends!! 

[Summer Sun]

Pretty steady from GFS so far with -8 850's moving south during Friday

12z

06z

Edited January 9, 2017 by Summer Sun

[frosty ground]

So 84 hours out and there is not much change from the GFS..... Maybe a slight shift west. 

You can see the development of the low / wave pushing into the Atlantic high. 



GFS not backing down

Edited January 9, 2017 by frosty ground

[Ravelin]

Minor differences on the GFS 12z which is out to t84 so far. To my eyes though uppers look marginally colder IMBY, closer isobars so wind stronger and more of a northerly component to it.

[Summer Sun]

Could be following the 06z with the high edging in during Friday pushing the strongest winds into eastern Europe

Thursday                                                         Friday

Frequent snow showers in the west on Friday maybe merging into longer spells of snow at times

[bradymk]

UKMO +72, 13:00 Thursday, is that a new feature just to the south west of the UK? 

Also better than the GFS in the Atlantic again

[Snowman.]

Hold up 

UKMO developing a 2nd feature SW embedded in cold air. Could get really interesting.

Edited January 9, 2017 by SN0WM4N

[Captain Shortwave]

Differences already between the GFS and UKMO at day 3

   

The UKMO has a secondary low moving towards the south west of England, this could produce a snow event. It also allows the trough to dig further south across the UK, the GFS doesn't really develop this though there is a front across northern France at this point.

Day 4

   

UKMO more amplified with an unstable north westerly, the GFS is already beginning to flatten the pattern out with shallow lows riding along the jet stream and over the ridge, though it is a little better than the previous couple of runs with cold air remaining over the UK into Saturday.

Edited January 9, 2017 by Captain Shortwave

[Summer Sun]

Well well well

UKMO has a low to the south-west on Thursday

GFS at t72

So differences just 72 hours away this afternoon

Edited January 9, 2017 by Summer Sun

[frosty ground]

Differences starting to appear, the feature that flattened the ridge on the 06z run is now cutting through it further west.

12z
06z

Edited January 9, 2017 by frosty ground

[Weathizard]

No progress with the GFS. Stickingf to its guns.

[Man With Beard]

Monstrous difference at just T96 too - so much flatter on GFS still, and this little feature in the Atlantic. The sort of differences you'd expect at T168 when it's fully zonal.

  

[Mucka]

Also UKMO GFS comparison at 96h. UKMO has a Northerly driving throught he heart of France. GFS has a Northwesterly through Germany!

Hope GFS is being rubbish and I would have to back UKMO at this range.

[Hotspur62]

1 minute ago, frosty ground said:

Differences starting to appear, the feature that flattened the ridge on the 06z run is now cutting through it further west.

I think i like the UKMO a bit more at T72 lol.The GFS will just have a 36hr window for snow in NW Britain and then we will develop a more Westerly regime from the Atlantic to push through while the UKMO shows a different outcome going forward.

[Guest]

well i cannot remember a time when models still cannot agree at t72... so we are still none the wiser as to where we are heading. nice little feature on UKMO would throw up some surprises im sure...

[booferking]

This is getting stupid  look at difference 72hr and again 96hr crazy..

[bradymk]

UKMO much better than GFS for Friday too brrrrrrr 

[AWD]

1 minute ago, More Snow said:

well i cannot remember a time when models still cannot agree at t72... so we are still none the wiser as to where we are heading. nice little feature on UKMO would throw up some surprises im sure...

At around the T72 mark, some additional high res modelling such as the NMM should become available to view alongside the 3 main global models so it shouldn't just be a case of GFS vs ECM vs UKMO from here on in.

Will be interesting to see what the 12z NMM, Arpege etc predict when they are out.

[Ravelin]

2 minutes ago, booferking said:

This is getting stupid  look at difference 72hr and again 96hr crazy..

Nah, just keeps it 'interesting'. Lets see the ECM come up with a 3rd option later.

[Pembroke Dangler]

That little feature to the sw could be interesting down here embedded in sub 528 dam thicknesses would produce a fair bit of snow I would imagine sorry if a bit imby but haven't seen a flake for 5 years 

Edited January 9, 2017 by Pembroke Dangler

[winterof79]

Gfs never gets the -8 isotherm even half way down the UK before bogging off to elsewhere IN 6 WHOLE HOURS. I hate the GFS

[Mucka]

I expect the uppers would still be cold enough to give snow for many on that shortwave as it moved SE. Better East away from warm sector.

Edited January 9, 2017 by Mucka

[Ravelin]

Leaving aside the GFS/UKMO differences for now, the GFS at t144 is more amplified compared to the previous run...

06Z   12Z