Model output discussion 24/01/21

[Methuselah]

   

[Chesil View]

There's no need to fret over temperamental GFS or gem runs. The Meto via the latest 6-15 and 16-30 day outlooks  are fully on board and going forward that is all we need to know. You'll find it  saves a lot of angst every six hours.

[Griff]

Para 144

[StormyLincs]

1 minute ago, General Cluster said:

   

Dear god, that’s a horror show! 

[ICE COLD]

The GEFS mean at T180 . 

[IDO]

No idea if the GFS 12z is right but it was more my thinking based on runs prior to the 06z. That seemed to be a strat response as it went from a wedge(s) setup to a warming in the trop at northern latitudes. Maybe it will be repeated in a subsequent run but it was a statistical outlier at the end so it was a wait and see?

This run looks similar to the earlier Greenland wedge colder spell where we got an easterly to our north and we were in the westerly undercut:

The first thing I usually look for is a repeating pattern, as that could indicate an underlying NH trop state. Hopefully this is just one run and a coincidence, but the above looks very familiar!

At this far out we definitely need lots more runs and hopefully more like the 06z as I suspect relying on wedges may be like chasing that pot of gold!

[MJB]

1 minute ago, ICE COLD said:

The GEFS mean at T180 . 

Stunning it has to be said 

[Methuselah]

1 minute ago, YellowSnow said:

Dear god, that’s a horror show! 

Trust the 12Z to have a Bartlett up its sleeve! It's got to be a rogue run... surely!

[Allseasons-Si]

5 minutes ago, Griff said:

I'm genuinely stumped, does it go mild or very cold? 

I have Edited the post as i didn't realize how rude it was

anyway the parra is getting there.

[TSNWK]

11 minutes ago, BLAST FROM THE PAST said:

Anyone else thinking we’re gonna get a relatively poor 12z set?...apart from UKMO which is very nice at t144

 

BFTP

Cup of tea, come back around 5:30 for the mean, ensembles in particular the spaggetti plot see where it lays - Although the spaggetti plots look dated in format they powerfully illustrate where a run sits - I'm hoping that dark Green lines is way at the top... and the control blue is amonst the main pack

[joggs]

17 minutes ago, MJB said:

DEEP DEEP DEEP into FI

Have to also remember just how different the 0z and 6z were , its a variation of the cold theme from the East 

We would kill for the above chart normally

Gfs overblows lows at that range. If that's the way forward I'd expect that to be alot weaker and disrupt. Another cold theme.

[StormyLincs]

1 minute ago, General Cluster said:

Trust the 12Z to have a Bartlett up its sleeve! It's got to be a rogue run... surely!

It’s an outlier. More runs needed

[East_England_Stormchaser91]

Could say we’ve hit the post with this run towards the latter stages. At least the idea to bring the initial blast of cold from the east is still there. 

On to the ECM we go. 

[Cheshire Freeze]

Weaker Arctic heights anomaly in the GEFS at D8, which isn't good to see...but could be inter-run changes.

As I said yesterday, so many pitfalls and hurdles to overcome with this set up. We're relying on luck and even if we do get that initial cold shot from the NE, it may only last a day or two.

I'm going to take a back seat over the weekend because IMO the whole set up is on a knife edge.

[Allseasons-Si]

The mean is a tad of an upgrade here at 192.

the ens are split at short range with the op on the mild side.

Edited January 29, 2021 by Allseasons-si

[nick sussex]

6 minutes ago, MJB said:

Just to clarify when you say downgrade you are talking about the OP .

No one can make any judgement until the ENS are out .

Take the Control , there is more in the way of cold over the UK at this point than on the 6z , so is that an upgrade ? 

The ensembles are useful but the wheels come off quite early here .  The changes though between runs aren’t though a surprise but the longer it takes to develop low pressure in northern Italy the worse the evolution will be . I’ve yet to see a single easterly that delivers without that key feature .

[Griff]

12 minutes ago, Allseasons-si said:

Yes,the door has opened up nicely,but a long way off and there is too many scenarios to pinpoint what is going to happen,lets get the trough digging further SE from 120 and go on from there.

 

 

3 minutes ago, Allseasons-si said:

I have Edited the post as i didn't realize how rude it was

anyway the parra is getting there.

Ha i was thinking out loud, we posted at the same time, I hadn't read your post, just my inner monologue, not a reflection on you at all!

Could go long fetch easterly on gem right? 

And I was about to post same // charts for Friday morning.

Looks good. 

FYI you're too quick

[ICE COLD]

The mean at T192 on the 12z is a slight upgrade on 850s from the 6z 

[londonblizzard]

GEFS looks like it's coming to the rescue

[Tim Bland]

Re ensembles...wouldn’t usually look at them for close range but this caught my eye for snow tomorrow at midday in the south...

[feb1991blizzard]

17 minutes ago, nick sussex said:

I think to be blunt this is quite a downgrade from the 06 hrs run and this all stems from the day 6 and 7 output.

The disruption of energy is too south and not se . You need low pressure in northern Italy as this funnels a wider pool of colder air sw wards , it also impacts the longer term in sustaining the block in a favourable position for any Atlantic attack .

After a weekend at the Ritz we’re now back to the Premier Inn. The UKMO is equally uninspiring .

Hopefully the ECM can repair some of the damage . 

Wait for the ensembles first, -6c mean reaches the South East where as a lot higher on the op, very precarious yet but you could still do better in the SE when it comes to verification than further North, i wouldn't mind betting on it TBH.

[Griff]

// looks marginally better than 06z run at 180 if that counts for anything? 

[feb1991blizzard]

Look at the clustering -8c to -10c in London now, another uupgrade if you ask me.

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

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Forecasted 850 hPa Temp. from GFS, 12Z

 

[Duncan McAlister]

14 minutes ago, General Cluster said:

   

Last February a run that looked like the 12z from ~156-240 would have been like a dream 

[londonblizzard]

Best 850 mean of the entire winter so far at around day 9. It gets under -7 for London now