Model output discussion - The run up to Christmas

[Allseasons-Si]

The 06z run brings the Greenland height's in three days earlier than the 00z,...same scenario.

06 246 v's 00z 318.

great output this morning and gaining momentum now.

 

Edited December 23, 2020 by Allseasons-si

[kold weather]

2 minutes ago, mountain shadow said:

Nothing much has changed in the past couple of weeks.

Synoptically,  the hemispheric pattern is great but unless you live up a hill in Scotland,  there is very little chance of snow in the next ten days.

That is the reality.

I don't agree MS, there is a heap of potential for snow, especially from the 28-29th. You've got cold uppers aloft (500mbs looks more than good enough), low thicknesses, a wind flow that as any secondary lows that form swings the winds from Europe and any evaporative cooling IMO males a really compelling argument for plenty of snow if there are active fronts in the area.

A near carbon copy set-up gave a fairly decent chunk of EA and Kent snow from an milder version of this a few weeks ago. This time nearly every metric looks colder.

[tight isobar]

6 minutes ago, mountain shadow said:

Nothing much has changed in the past couple of weeks.

Synoptically,  the hemispheric pattern is great but unless you live up a hill in Scotland,  there is very little chance of snow in the next ten days.

That is the reality.

Wow.. bold statement is cutting it nice.. your obviously taking a by now locked in pattern and gambling everything you’ve got in the high odds hoping you’ll win???!!   Every suite for nearly 24 hrs has bound snow chances almost anywhere between 28 December-1january..   and there are plenty of signals for ramping up, considerably.. the forte we are already viewing... and not to mention glancing blows b4 the stated.. what are you viewing???!!

Edited December 23, 2020 by tight isobar

[TSNWK]

4 minutes ago, bluearmy said:

Gonna  be squeaky bum time on this run very soon .........

You thinking  west based nao?

with this lot to our south west scooping up air from Atlantic 

Edited December 23, 2020 by TSNWK

[Kasim Awan]

3 minutes ago, Mapantz said:

Although it  is a bit far out for a high resolution model, it does show the possibilities of disturbances around a parent LP.

That would produce snow for South Wales and higher ground in the Southwest.

They'll be so many small things to watch out for in the coming days!

-5 will be ample for pretty much all ppn in this set up with light winds. This is akin to -8 in a showery sea run feed.

Edited December 23, 2020 by Kasim Awan

[kold weather]

5 minutes ago, bluearmy said:

Gonna  be squeaky bum time on this run very soon .........

Get the feeling it may just be a touch too far west and we may end up in the hands of a SW (at least the south) in deeper FI on this run. Its quite a restricted upper high in terms of size and so could probably do with being a couple of hundreds miles SE.

Could be decent snow further north from it mind you.

Edited December 23, 2020 by kold weather

[SteveB]

6 minutes ago, mountain shadow said:

Nothing much has changed in the past couple of weeks.

Synoptically,  the hemispheric pattern is great but unless you live up a hill in Scotland,  there is very little chance of snow in the next ten days.

That is the reality.

Are you too far West by any chance! Cold for Mainland UK,  but not so for Ireland. 

[Djdazzle]

Can someone please explain what is meant by a west based nao?

[bluearmy]

1 minute ago, TSNWK said:

You thinking  west based nao?

its going to bust by T300 on this run .... there were plenty of gefs runs than weren’t great post T300 ....surprised there wasn’t more noise on this earlier.  Just an apple plucked from the tree at this stage though ....

[kold weather]

Just now, bluearmy said:

its going to bust by T300 on this run .... there were plenty of gefs runs than weren’t great post T300 ....surprised there wasn’t more noise on this earlier.  Just an apple plucked from the tree at this stage though ....

Yes my ears were twitching from as early as 192hrs on this run (my first post on the 06z run said I thought it might be a touch too fr west)

Its a risk for sure, and as you say there were some ensembles that went down this path and it is certainly possible if everything does setup too far west...

Which would be typical right!

[Howie]

Yeah west based -NAO forming on this run but it's too far out to be concerning no? 

[tight isobar]

Yeole crab claw .. or omega block.. she’s eyes only for shutdown!!! 

[bluearmy]

1 minute ago, Djdazzle said:

Can someone please explain what is meant by a west based nao?

Look at this run dazzle

Low heights Azores, high heights greeny = neg NAO

but if this is too far to the west then the Azores trough pivots ne and lifts the flow into Europe from the sw 

[Sky Full]

And now, a pre-Christmas prayer to our own special god...

Our Father, who art in ‘ternet,

Netweather be thy name;

thy models run;

thy charts be done;

on earth as it is in heaven.

Give us this day our daily thread.

And forgive us our ramps,

as we forgive those who ramp against us.

Lead us not into zonality,

But deliver us from mild.

For thine is the UKMO,

the GFS and the ECM,

for ever and ever.

Amen.

And now, altogether, the Netweather mantra....

“LET’S GET THE COLD IN FIRST”

️️️

Merry Christmas, everyone!  Let’s hope we all get a dumping before the New Year.  And don’t share those mince pies with anyone outside your bubble....

[TSNWK]

Another 2020 surprise.. we need the Greenland high to topple!!!!

[chionomaniac]

Frustrating to see something so close. The cold gets closer from the NE but the milder air comes from the south. LOL the block may be slightly west based, but it is also too far north so that the Atlantic gets the easterly!

[kold weather]

1 minute ago, Howie said:

Yeah west based -NAO forming on this run but it's too far out to be concerning no? 

Its worth keeping a watchful eye on it is the best way to describe it.

06z GFS is it came off might just about be ok for N.Egland and Scotland, the rest of the country ends up in milder air by 300hrs, though with a surface flow from the SE it won't feel that way at the surface.

[kold weather]

1 minute ago, chionomaniac said:

Frustrating to see something so close. The cold gets closer from the NE but the milder air comes from the south. LOL the block may be slightly west based, but it is also too far north so that the Atlantic gets the easterly!

The other thing is the actual block itself is one of those small ones on this run, so effectively we need the core much closer to our shores. The 00z GFS for example is much larger so the core placement doesn't matter as much.

It may end up eventually opening up again from the NE down the lin,e but we'd have wasted 4-7 days of prime time blocking to get to that point if the 06z GFS was right.

[Guest]

12 minutes ago, mountain shadow said:

Nothing much has changed in the past couple of weeks.

Synoptically,  the hemispheric pattern is great but unless you live up a hill in Scotland,  there is very little chance of snow in the next ten days.

That is the reality.

I think that is an unduly pessimistic outlook given many areas at even a half decent altitude will be at risk of seeing snow over the coming week to ten days.

To say 'very little chance' away from Scottish mountains, given small features and disturbances will appear at very short notice almost anywhere, in a cold setup when days are at their shortest, is setting yourself up for a fall which (with all due respect as you're normally a little more pragmatic) I hope you take*

*For the benefit of the coldies

[Jeremy Shockey]

Christmas Eve 6pm

Christmas Eve 9pm

Our new friend Harmonie 06 z brings some snow showers for Eastern counties tomorrow evening. Very festive !

[bluearmy]

Just now, chionomaniac said:

Frustrating to see something so close. The cold gets closer from the NE but the milder air comes from the south. LOL the block may be slightly west based, but it is also too far north so that the Atlantic gets the easterly!

Yes Ed - I should have added to my post to dazzle that if the greeny high is too far north then it allows the jet to be also too far north and the lw trough on a west to east axis at a latitude which means it heads ne before it gets to Europe ....

[Sceptical]

14 minutes ago, mountain shadow said:

Nothing much has changed in the past couple of weeks.

Synoptically,  the hemispheric pattern is great but unless you live up a hill in Scotland,  there is very little chance of snow in the next ten days.

That is the reality.

Theres yellow warnings, for snow and ice, that cover the northern half of Scotland today and tomorrow.

[sheikhy]

Doesnt matter which way you look at it!!west based east based north based its cold regardless!!!!looks whats coming in from the north east!!06z threatened a west based nao but never went full whack so now the low is disrupting!

[southbank]

although a potential solution remember we are talking about the GFS6z + 300 , its just about trends nothing more the surface features will be completely different 

[Nick F]

Looks a bit west-based -NAO to me from day 9, fortunately FI is quite close in range at the moment. Nice seeing Greeny high, but the block not exerting far enough SE to stop Atlantic lows rolling in west to east toward UK on this run.

Edited December 23, 2020 by Nick F