Model output discussion - Closing in on Christmas

[That ECM]

So the gfs took a mahoooooosive step towards the ukmo right? Cause that always happens.

[Sweatyman]

2 minutes ago, blizzard81 said:

And just keeps on giving. 

that is one lovely mean

[sheikhy]

Mean is a massive improvement!!more ridging into greenland!!!this could actually be happening guys❄

[Allseasons-Si]

The gfs  looks OK for these guys in the Atlantic....

joke aside,it is still showing the same synoptic outlook that it has been showing for a couple of days now so that's a good trend and the overall pattern is in similar format,it's way too far out for the fine details yet so i wouldn't worry about it for now

here are gfs,UKMO,gem and ICON at 144 hrs

the key here is as someone mentioned is the amplifying downstream trough in eastern states of America,the more amplified the better upstream ridging into the Atlantic,the other factor to take into account is that Arctic/Urals high of which again will play it's part further on into the output.

 

 

[Scott Ingham]

1 minute ago, Sweatyman said:

that is one lovely mean

The mean further east with the Polar low. Thats good to see!

[Jeremy Shockey]

UKMO 12 z for Christmas Eve 850s

GFS 12 z Precipitation charts for Christmas Eve 

Any precipitation on 24th down the East coast (and a bit further inland perhaps ) would likely be Wintry. Will be interesting to watch Arpege and other high res. models over the coming days. Upgrades possible with the -8 isotherm in place for parts of the UK

[SLEETY]

9 minutes ago, swfc said:

Amazing from a semi greenland high and northerly to a south westerly???

yeah like a gfs chart in fl ever verifies,even before then the run looks suspect,too much concern about gfs charts over t+192 hours again

[nick sussex]

Just now, Howie said:

Interesting! So hopefully a halfway house would be decent?

It’s important to build sufficient heights into Greenland so we do need the amplification but timing could be crucial .

So more about when that happens . The key feature is that shortwave you see over the eastern seaboard .

That pivots, to its right warmer air pushes north into west Greenland which promotes heights building by WAA.

As the jet amplifies upstream heading north , downstream the jet goes south taking that low near Greenland s/se.

The coldest air will be on the nw and west flank of the low so that needs to get to the se of the UK and not just fill over the country .

[swfc]

2 minutes ago, SLEETY said:

yeah like a gfs chart in fl ever verifies,even before then the run looks suspect,too much concern about gfs charts over t+192 hours again

It's was tongue in cheek f--,chill out 

[Weathizard]

This is the MEAN, yes yes a thousand times YES.

[Howie]

Just now, nick sussex said:

It’s important to build sufficient heights into Greenland so we do need the amplification but timing could be crucial .

So more about when that happens . The key feature is that shortwave you see over the eastern seaboard .

That pivots, to its right warmer air pushes north into west Greenland which promotes heights building by WAA.

As the jet amplifies upstream heading north , downstream the jet goes south taking that low near Greenland s/se.

The coldest air will be on the nw and west flank of the low so that needs to get to the se of the UK and not just fill over the country .

Fingers crossed! The mean is much further east with the low so hopefully the operational run was an outlier

[Skullzrulerz]

6 minutes ago, sheikhy said:

Mean is a massive improvement!!more ridging into greenland!!!this could actually be happening guys❄

It's not over till it's over 

[Scott Ingham]

4 minutes ago, SLEETY said:

yeah like a gfs chart in fl ever verifies,even before then the run looks suspect,too much concern about gfs charts over t+192 hours again

I think your thinking about the GFS with other syoptics. Like Steve Murr says. The GFS is absolutely the best model in this situation. Id bet my house on the ECM moving further to the GFS than the other way round but there will be a coming together. Id say 70% to 30% GFS blend

[Battleground Snow]

5 minutes ago, nick sussex said:

It’s important to build sufficient heights into Greenland so we do need the amplification but timing could be crucial .

So more about when that happens . The key feature is that shortwave you see over the eastern seaboard .

That pivots, to its right warmer air pushes north into west Greenland which promotes heights building by WAA.

As the jet amplifies upstream heading north , downstream the jet goes south taking that low near Greenland s/se.

The coldest air will be on the nw and west flank of the low so that needs to get to the se of the UK and not just fill over the country .

I guess we would want something like p19 then Nick? High further east around Greenland which nudges the trough further east too, which allows us slightly colder uppers over UK

Edited December 19, 2020 by Battleground Snow
Typo

[That ECM]

3 minutes ago, Howie said:

Fingers crossed! The mean is much further east with the low so hopefully the operational run was an outlier

 

[Scott Ingham]

3 minutes ago, That ECM said:

 

Many more with Atlantic n Greenland highs. Some momentum building. Lets see where we are come the 12z on monday 

[Allseasons-Si]

The gefs mean at 240 and much more improved from this mornings with the Atlantic ridge.

 

[Sweatyman]

10 minutes ago, Weathizard said:

This is the MEAN, yes yes a thousand times YES.

yes

[Matt H]

A few more GEFS 12z ensemble members dropping to the -8C territory this afternoon. Slow progress, certainly nothing overly mild on the horizon!

[That ECM]

3 minutes ago, Frosty Winter said:

A few more GEFS 12z ensemble members dropping to the -8C territory this afternoon. Slow progress, certainly nothing overly mild on the horizon!

A lot more below the op than above it towards the end.

[Jason M]

Looking at the output tonight I'm thinking more about rainfall amounts tbh. Could be some really nasty secondary lows spawned off the base of such a deep trough. Lots of snow to high ground? lots of flooding in some other places.

Could be great for the Scottish Ski industry though.....oh, wait, were all under house arrest until Easter .

[Cold Winter]

Just now, That ECM said:

A lot more below the op than above it towards the end.

Yes I noticed that, nice to see the op isn’t at the colder end 

[Scott Ingham]

1 minute ago, That ECM said:

A lot more below the op than above it towards the end.

Quite a few below the opp for Christmas day as well. The near term is coldening up never mind mid

[Scott Ingham]

1 minute ago, Jason M said:

Looking at the output tonight I'm thinking more about rainfall amounts tbh. Could be some really nasty secondary lows spawned off the base of such a deep trough. Lots of snow to high ground? lots of flooding in some other places.

Could be great for the Scottish Ski industry though.....oh, wait, were all under house arrest until Easter .

Its not necessarily just to high ground with the thicknesses and slack cold dense air. I think were in danger of underestimating snowfall potential 

[feb1991blizzard]

The GEFS are a relative stonker, will the eps follow suite after a few downgrades recently?