Model output discussion - late November

[SMU]

ICON more amplified through 108 in the atlantic over & above the 12z 114!

It will only go out to 120 however could we see that advection getting more vertical !

[MATTWOLVES 3]

For anyone who have not viewed the extended ens from ECM out to the 9th of December...... Not all bad... The mean for the Midlands is still just under 0C for the most part, and for Scotland we have it closer to - 3C. So at this stage I'm not seeing real signs of a milder SWtly type scenario pattern setting up. I think we start the new month on a colder note, and I wouldn't be surprised for this to become more stubborn than some think it maybe.... LRF to fail 2 years running...... What an Headline that would make.

[Mucka]

Icon sticking to its guns 18z (actually marginally better than 12z at 120h

 

18z/12z

 

Edited November 24, 2019 by Mucka

[feb1991blizzard]

4 minutes ago, Steve Murr said:

ICON more amplified through 108 in the atlantic over & above the 12z 114!

It will only go out to 120 however could we see that advection getting more vertical !

Yes looks an improvement with a sharper upper ridge at 120 - so even better - an improvement coming off an already high base as the 12z ended a stonker!

EDIT : beaten to it.

Edited November 24, 2019 by feb1991blizzard

[WxHerts]

ICON 18z, as well as having improved amplification due to WAA being even more vertical than earlier, is also further west than 12z with deep cold closer to us by d5...GFS will make for very interesting viewing if it shows the same - think we've latched onto something really significant today and who would've thought it just judging solely by the models 2/3 days ago?! Something tells me the coming spell could be more than transient too, let's hope the OP runs begin to toy with that scenario...if not though, how often do we get to say that cold weather looks set to start bang on cue with meteorological winter? Interesting times ahead

[Jordan S]

A quick look at the wet weather tonight with arome below..

2am..tomorrow

4am..

6am..

Showery areas of rain perhaps quite heavy in a few spots pushing northeast tonight followed by heavy showers behind. 

Now the Ecmwf update is blended with the Gem and Gfs here's the average synoptic output from all three for the weekend into monday as there is a fair amount of interest regarding this period.. 

Sunday 1st..

2nd..

You can see the trend has shifted to have higher pressure out West with an obvious northerly flow for the UK. Quite cold too with some wintry showers for particularly northern and Eastern areas. This northerly then shown to turn northeasterly as that high starts to topple over the country and by Wednesday 4th it sits to the south of the UK with an Atlantic flow coming in but how quickly this happens is still open to doubt as you would expect at 7-10 days away.

4th..

In the meantime pretty wet with the GFS here's an animation of the next 10 days..

GFS 10 day accumulated rainfall chart below..

GFS 10 day temperature anomaly chart below

Colder than average generally. 

GEFS.. Temperature anomaly for the next 10 days too..

Milder than average at first during this week then Colder than average temperatures generally shown. 

GFS ensembles..

Quite a few rainfall spikes showing throughout the period for the next week or so although drier days early next week likely. Upper air temperatures above average then dropping to below average after the end of the week then remaining below for a few days before shown to lift back to atleast average. 

Gem ensembles..

Note the upper air temperatures only drop close to average or slightly below for a time late this week compared with the gfs before rising quite a bit above average although it must be noted there are some very cold ensemble members there but they are the minority atm with the majority trending mild. 

Edited November 24, 2019 by jordan smith

[SMU]

Off we go 18z

Here is the daddy of Vertical advection Nov 21 2010

[northwestsnow]

Just now, Steve Murr said:

Off we go 18z

Here is the daddy of Vertical advection Nov 21 2010

I'm not overly bothered about GFS - its a junk model.

The 00z UKMO run tomorrow holds most interest for me, i'm on nightshift so will seeyou here about 4am steve

[Allseasons-Si]

36 minutes ago, Steve Murr said:

Just as the 18z fire up a reminder of where we want to see the under cutting developing

Also the ECM control goes deep cold out to day 15 !

It is a cold outlier though Steve so hope it's a trend setter

my interest lies at the weekend into early next week(black circles),could we possibly get an easterly in!

Just waiting for the 12z London eps ens to come out but this mornings wasn't bad.

 

[Mike Poole]

16 minutes ago, Steve Murr said:

Off we go 18z

Here is the daddy of Vertical advection Nov 21 2010

Steve, if you are pressing the starting gun on a model watching shenanigans for a repeat of Dec 2010, then I'm the first to back you up, not sure it will be resolved by the pub run, but it might be, let's see....... 

 

Edited November 24, 2019 by Mike Poole

[ALL ABOARD]

16 minutes ago, Steve Murr said:

Off we go 18z

Here is the daddy of Vertical advection Nov 21 2010

Just to show people how background signals can sometimes skew a FI on a model until such an event happens. 

For example this chart was taken on the 19th of November GFS for the 21st

 

 

And 384 hours of the same run 

 

What actually transpired. 

 

 

Hold onto your hats it's going to be a fascinating ride. 

 

I'll add a bit so that it's relevant as don't want it moved although one would argue I'm highlighting sufficient details as to why the models shouldn't be taken at face value until said amplification has taken place. 

The icon was an improvement from the 12z and although we can't see it any further I'm expecting the 18z to pick up the baton. 

Edited November 24, 2019 by ALL ABOARD

[Mapantz]

Can we keep to the present day, please?

There are other threads for discussing previous weather events.

Cheers!

[Mucka]

GFS already a slight improvement over the 12z.

So long the upgrades keep coming tomorrow should be exciting.

No more commentary from me, hope it is a pub run special.

Edited November 24, 2019 by Mucka

[Allseasons-Si]

Just touching on the ICON and how consistent it is...

today's 12z 156 v  12z 180 yesterday.

 

 

 

[shaky]

Guys what's happening with the 18z!!any improvementsthe icon 18z looks pretty darn good at 120 hours!!

[Allseasons-Si]

2 minutes ago, shaky said:

Guys what's happening with the 18z!!any improvementsthe icon 18z looks pretty darn good at 120 hours!!

Not much at 120,just slightly higher heights ahead of the trough in the Atlantic of which should be a good thing.

[Jordan S]

This low on Saturday needs close watching as it may move into the southern half of the uk this will be moving into pretty cold air over the Uk. 

GFS below.. 

Saturday 6am.

Rainfall..

Freezing level..

This is obviously a fair few days out so some uncertainty will ofcourse exist and any snowfall will likely be confined to hills but that's if the rain makes it north enough, I suspect in future runs this low will be trended south though. 

Edited November 24, 2019 by jordan smith

[StretfordEnd1996]

HP looks a tad further East (and South) at +150 to me

[Allseasons-Si]

At 144 hrs and there is better heights in the Atlantic but i fear this will topple more,hmmm!

18z v 12z 

[bluearmy]

The WAA on the 12z was better ....the interest for me on this run given that change is how the cold high behaves to our north in the day 6/8 period 

[Mucka]

I came back to apologise for myself and GFS. 

It actually did start well out to 60h but then goes mental with the rapid cyclogenesis of the low as it crosses N.America.

That is why should wait a little longer before calling them I guess but I give GFS at least half the blame 

I guess tomorrow will reveal whether the 18z is onto something or just a pile of 

ensembles might also help.

Edited November 24, 2019 by Mucka

[SMU]

& That concludes the runs for the day - 18z to far East compared with the ICON - remember the Advection needs to be west of the SW tip of Greenland.

May be an ok run but onwards to the 00z

[feb1991blizzard]

As long as the GEFS hold rock solid i wont be losing any sleep over the op.

[StretfordEnd1996]

Hmmm yes just doesn't quite cut the mustard on the GFS 18 op..

HP topples in perhaps a tad quicker compared to other runs today - 

But it'd be still cold - as indicated by the uppers, with the -5 isotherm getting down over much of the country throughout much of the period from Friday to Sunday.

It's not a dream run but its acceptable - more so if it turns out to be one of the 'milder' runs in the suit - (milder meaning in this particular comment, toppling the HP in too early).

 

[Jordan S]

4 minutes ago, StretfordEnd1996 said:

Hmmm yes just doesn't quite cut the mustard on the GFS 18 op..

HP topples in perhaps a tad quicker compared to other runs today - 

But it'd be still cold - as indicated by the uppers, with the -5 isotherm getting down over much of the country throughout much of the period from Friday to Sunday.

It's not a dream run but its acceptable - more so if it turns out to be one of the 'milder' runs in the suit - (milder meaning in this particular comment, toppling the HP in too early).

 

Whatever happens it looks quite cold as we head into the first couple of days of December which will be a nice opening to meteorological winter.