Model output discussion - Into 2021

[Scott Ingham]

3 hours ago, Jon Snow said:

Holy Cow..here’s the GEFS 6z mean, chart order all over the place..go figure!...and for the most part it’s jolly cold..with a risk of snaw..a far cry from recent pathetic winters!..of course, I realise this is not set in stone..what is beyond 3 days..hmm?...but I have a good feeling about where this winter is heading compared to recent abysmal ones!..

Knock 2 degrees off them temperatures if you follow actual ground conditions the past week to what the model is showing

[damianslaw]

Not looking much beyond the 144 hr timeframe at present. Within this timeframe a transition to a chilly easterly, though not especially cold. Wintry showers of rain, hail, sleet and snow for some, more so eastern parts but with the strong wind, these will push into central parts at times. Frostiest conditions in the far west and north west.

By the 7th a change is forecast, low heights dropping down from the NW to slice through the strong heights overhead, these then set to ridge NW . What happens next unclear, much will depend on the depth and strength of the low heights and associated trough. We could be looking at another spell of weather akin to the week just gone, conversely we may see something substantively colder with a robust block setting up to our NW, or we may see heights ridge too far NW and allow the atlantic back in  (the west based negative NAO scenario), but not with any real gusto - battleground situation cold air holding to the north, milder air to the south, the former possibly winning out..

 

Edited January 1, 2021 by damianslaw

[Scandinavian High.]

17 minutes ago, Tim Bland said:

Nationwide snow event next weekend from the GEM as that low slides south... 

Just seen this on bbc longer range forecast big Area of snow moving across uk and looked low pressure sliding across southern England.

[bluearmy]

Just now, Scandinavian High. said:

Just seen this on bbc longer range forecast big Area of snow moving across uk and looked low pressure sliding across southern England.

That’s just the raw ec 00z op.  Will be different by the time the ink is dry on this post !

[Gowon]

The GEM is my favourite 

[Matt H]

The GEFS 12z mean at t192 looks fairly good to me with a cold northerly flow, albeit with many options still on the table within the individual ensembles. Also stronger with the Atlantic ridging compared to the 06z mean FWIW.

Edited January 1, 2021 by Frosty Winter

[Tim Bland]

8 minutes ago, Scandinavian High. said:

Just seen this on bbc longer range forecast big Area of snow moving across uk and looked low pressure sliding across southern England.

As BA says it’s the ECM. I don’t think Meteogroup bother subscribing to any other model

[Penicuikblizzard]

46 minutes ago, Frosty Winter said:

Parallel run is a stonker, no messing around here!

Can I ask what is the difference between the parallel run and the normal run, are all these models reliable or is it just finding the coldest charts?

[Scott Ingham]

1 hour ago, Steve Murr said:

GFS ever so slowly over 24 hours has crept to the UKMO kink, as a result the milder pulse has receded

Also as a result of the northward movement of the kink in Europe ( East ) the angle of CAA over the UK has been moving the coldest uppers south.

If we look at 12z V 06z it's noticable 

But now compare just 24 hours ago

l

 

Those small increments result in a 3-4 degree drop in the SE... 

We also see this pool more widespread for monday eve > With such an expanse of -8c & the map set at 2 degree increments the likleyhood is there -9c in the middle!

 

As we progress 108 is much colder as well !

 

UKMO is great much better than 00z but 144 is 9/10 not 10/10 as we need the atlantic high with no positive tilt at all...

 

Thanks

This is classical cold air building in situ.

Usually takes a week and well be there by then

[I remember Atlantic 252]

Bartlett generally means shorts out and no jacket! think this is one

 

[Radiating Dendrite]

1 minute ago, I remember Atlantic 252 said:

Bartlett generally means shorts out and no jacket! think this is one

 

My eyes.... they're burning!

[Bartlett High]

5 minutes ago, I remember Atlantic 252 said:

Bartlett generally means shorts out and no jacket! think this is one

 

Let's move on.

[Froze were the Days]

22 minutes ago, BLAST FROM THE PAST said:

UKMO would if it continued

Got a crystal ball?...difficult to tell the main trough is well to the north unless we get a separation with the Scandi ridge. 

[northwestsnow]

As others have said , until we get some clarity 120-144 with the low dropping through the rest is well, debatable...

[Djdazzle]

1 minute ago, Bartlett High said:

Let's move on.

How apt, considering your username!

Back to models - a lot of scatter in the ensembles so caution still required. But next week’s easterly looking much better.

[Guest]

31 minutes ago, Tim Bland said:

Nationwide snow event next weekend from the GEM as that low slides south... 

 

Thats a bugger, Ive just moved to Barclays!

On a serious note remember the North Sea cools at a rapid rate this time of the year, Thats when the North Sea turns into a snow machine, and with the setup we have its only a matter of time before the fun and games begin!

[northwestsnow]

Just now, Djdazzle said:

How apt, considering your username!

Back to models - a lot of scatter in the ensembles so caution still required. But next week’s easterly looking much better.

Agreed...

Just a few minor upgrades over the next 24 hours wouldn't be objected to by ,well, 99.99% of this forum anyway lol.

[winterof79]

8 minutes ago, I remember Atlantic 252 said:

Bartlett generally means shorts out and no jacket! think this is one

 

Uppers look iffy for any falling snow......

[Froze were the Days]

4 minutes ago, Snowmut said:

On a serious note remember the North Sea cools at a rapid rate this time of the year

Does it? the continent does if the right conditions not sure about SST's in the central area of the North Sea, somewhat more in coastal areas (around 0.1c a day if conditions are again favourable).

Edited January 1, 2021 by Froze were the Days

[Captain Shortwave]

UKMO is fine to me...

Day 5/6

         

Yes the parent low is moving almost due north, but you can see the split jet and the sharpening trough sinking southwards towards the UK. This will bring sleet/snow southwards within a frontal system before the Euro low reinvigorates. The Atlantic high will remain in place, especially as Arctic air will likely interact with the low south of Newfoundland that will create a sharp trough along the Eastern seaboard.

All speculation at the moment of course, but I am struggling to see the pessimism in this outcome. 

[winterof79]

3 minutes ago, D.V.R said:

Poor Eskimo got proper told off for mentioning Bartlett in here  

Even T*scos would have put him on naughty list

[winterof79]

Do we think GFS // is showing the relaxation of cold mid month or has it just got lucky

[Thinon]

5 minutes ago, winterof79 said:

Uppers look iffy for any falling snow......

Yes and many amateur forecasters often overlook the fact that the easterly air flow will likely warm up at the surface as it crosses the North Sea before reaching the UK despite the uppers seeming to be low enough, hence the Meto going with the rather underwhelming but sadly very justified marginal outlook 

[Methuselah]

57 minutes ago, Eskimo said:

Anyone for a Bartlett?


 

He's not a Bartlett, he's a very naughty boy!

[MATTWOLVES 3]

Ok,perhaps not Boom charts just yet,but come on...how much better do things look than the last few years...even Exeter have jumped aboard..Only a matter of time before I will be posting....kaboom charts some cracking ens again from the 12z...they open the Arctic floodgates at times..before  you know it we will have penguins in the street.

Edited January 1, 2021 by MATTWOLVES