Model output discussion - Closing in on Christmas

[Cheshire Freeze]

1 minute ago, Mucka said:

2020 going out with a bang according to this run with a crazy Winter storm and blizzards for the N 

 

Yep, it's actually a part of the TPV being displaced. Crazy.

[Had Worse]

That will be " The day after tomorrow " storm that somebody eluded to further up the thread.

[Mucka]

3 minutes ago, CreweCold said:

Yep, it's actually a part of the TPV being displaced. Crazy.

I would love to see it but next run GFS will have high pressure there instead. 

[Cheshire Freeze]

1 minute ago, Mucka said:

I would love to see it but next run GFS will have high pressure there instead. 

Yep some low thicknesses under that- would ensure snowfall at -6 uppers

[SLEETY]

Highlands would get buried at the end of this run, but this is the gfs we are talking about, so might as just laugh at it, when you compare it to the previous run

[Bartlett High]

9 minutes ago, SLEETY said:

Highlands would get buried at the end of this run, but this is the gfs we are talking about, so might as just laugh at it, when you compare it to the previous run

Does seem a bit odd when you compare it to the 18z ...like chalk and cheese.

[DavidS]

GFS setting up a game of Spot the Difference n FI with the 18z and 00z..........I don’t think it understands the premise of the game.

 

[Battleground Snow]

6 hours ago, Battleground Snow said:

Still a fair few decent ensembles out to Xmas eve (180 hours) 

P16 for example... It will be interesting to see the 0z Ukmo at 144 before being too disheartened by the 18z GFS

 

 

 

So a swing back to a colder prospects on the 0z runs so far.... Generally I usually find the overnight runs tend to swing away from a colder outlook for some reason, so this is encouraging for coldies.

Here is the 144 Ukmo. Not A bad chart... We need the low near the Azores to prop up the high and the low near the ESB to intensify and move north or north west to help pull the high directly northwards... Still time to squeeze a little snow for some parts for Xmas Eve and Xmas day... I think the ECM will look a lot better than the 12z in an hour.

Edited December 17, 2020 by Battleground Snow
Typo

[Frosty.]

Happy New Year to all coldies from the GFS 0z operational!

[swfc]

Morning. Looking at the output this morning seems things are again looking better but towards the new year now. Been some great fi charts recently again and now we're looking way ahead for anything giving a cold /chance of snow shot. Ukmo looks a bit flatter this morning. Anyway hopefully reverse psychology works here and the 6z shoot me down.

[Griff]

4 minutes ago, swfc said:

Morning. Looking at the output this morning seems things are again looking better but towards the new year now. Been some great fi charts recently again and now we're looking way ahead for anything giving a cold /chance of snow shot. Ukmo looks a bit flatter this morning. Anyway hopefully reverse psychology works here and the 6z shoot me down.

So let me get this right, as I prepare to force myself into the world for another day of hard graft (making a TV show about Railway Architecture look pretty - hard life but somebody has to do it), 00z has swung back to a cold shot for Christmas eve and even reloads again at the end of FI? 

Let me guess, outlier? I hope not  

[carinthian]

The UKMO chart makes less of a feature and starts to fill in the low between the British Isles and the Azores compared to the GFS.  Either way looks like a colder Christmas spell for you guys compared to recent  years. Still the day to day detail not decided but the latest UKMO has more extensive colder air covering the British Isles by the middle of next week. See where we go from here !

 C

[Cheshire Freeze]

1 minute ago, Griff said:

So let me get this right, as I prepare to force myself into the world for another day of hard graft (making a TV show about Railway Architecture look pretty - hard life but somebody has to do it), 00z has swung back to a cold shot for Christmas eve and even reloads again at the end of FI? 

Let me guess, outlier? I hope not  

I've looked at the GEFS ensembles and this is no exaggeration...only a handful of members (maybe 20%) don't show a mangled vortex by the end of FI. 20% may even be too generous. A lot of N'lys in there.

[That ECM]

26 minutes ago, CreweCold said:

I've looked at the GEFS ensembles and this is no exaggeration...only a handful of members (maybe 20%) don't show a mangled vortex by the end of FI. 20% may even be too generous. A lot of N'lys in there.

Agreed.

This is why there is so many variations in later output. This is why there is low confidence from the professionals. This is why this year is far more interesting and fascinating than many. This is why toys will be thrown if we don’t get a half decent cold spell.

 

ECM still going for a festive Christmas Day.

Edited December 17, 2020 by That ECM

[carinthian]

28 minutes ago, carinthian said:

The UKMO chart makes less of a feature and starts to fill in the low between the British Isles and the Azores compared to the GFS.  Either way looks like a colder Christmas spell for you guys compared to recent  years. Still the day to day detail not decided but the latest UKMO has more extensive colder air covering the British Isles by the middle of next week. See where we go from here !

 C

A bit of a difference showing between the UKMO and latest ECM op run at 144h.  ECM makes more of a feature of the Low and holds much of England and Wales in the milder air mass longer. So looks like UKMO may be out on its own this morning.  Who will be right or none of the main models out at 144t  ? Keep watching folks !

C

Edited December 17, 2020 by carinthian

[TSNWK]

Darn you ECM looks like you’re continuing with the toppling high route post Christmas Day 216 not unlike 240 yesterday..

[tight isobar]

Gotta be honest I like the ec this morning.. and from Xmas eve/boxing day the opportunity for a good few seeing the white stuff in 1 descript or another.. is beginning to ramp up.. finer details between models now.. on hits n misses .. things getting “really interesting now”@ Christmas period!!!!.. the details beyond there are massively up for debate... but perhaps even more interesting..@going into early January!!

Edited December 17, 2020 by tight isobar

[carinthian]

Looking at the temperature profile from ECM, looks like much Euroland heading for a mild spell after a short cold spell over Christmas.  Maybe, its out in its own on this particular run .?

C

[bluearmy]

As has seemed likely for a while now, the initial Atlantic ridge is flattened before it can do much damage so we don’t bring down any really cold uppers, nor do we drive a wedge to disrupt the next trough and deflect/split the jet  

and now it also seems unlikely that the following amplification will be particularly notable with a mid Atlantic/east Atlantic  high of some description the probably outcome - we will become reliant on the development of an upper sceuro trough to bring us any really wintry conditions as the Atlantic ridge will ebb and flow (with the chance of a transient northerly) - and we know how unpredictable euro troughing is and how it generally fails to deliver rather than the opposite ..... hemispheric developments from top to bottom will continue to keep this place fairly busy .....

[West is Best]

Reasonable prospects of a 2 - 3 day colder spell to coincide with Christmas. Nothing seismic and my big worry is that these northerlies have a nasty habit of downgrading at the last minute which is what I expect to happen again. This is all the more the case given the evolution of the ECM which looks very likely to me going speedily from:

 

to this:

 

The ensembles are pretty mixed. Quite a bit of scatter and the 0z operational definitely on the colder side in the key period:

 

There continues to be one cold outlier which was insane on the 18z:

I don't think I've ever seen -15C 850hPa reached on an ensemble member before.

 

Generally though it looks like something more festive for the key two or three days. It's bizarre how often that happens. I would however urge some realism. Nowhere is going to 'get buried' by snow next week. Well, nowhere in Britain anyway. (Sleety was referring to a chart two weeks away rather than next week)

 

 

Edited December 17, 2020 by West is Best

[Penicuikblizzard]

4 hours ago, CreweCold said:

Worth pointing out, the signal for cold gets stronger now towards new year on the GEFS

Of course it does it’s past the 10+ day stage, next it’ll move to the middle of January then to the end of January and so on

[Daniel*]

I found progression quite odd 192 > 216 the ridge just collapses into main heights it seems rushed to me. 

GFS for same timeframes at 192 it’s really not that dissimilar different in Atlantic sector. And well 216 looks very different.

 

From what I’ve seen there’s flexibility to get a little more out of this than ECM 00z depicts.

[West is Best]

The likeliest progression is that a couple of days before the colder snap the 'northerly' will get slacker and slacker and turn into a damp squib. The ECM points the way here I suspect.

Sorry to be a grinch but we've all seen this sooooooooo many times. It needs to pep up considerably for the inevitable downgrade to retain potency.

Edited December 17, 2020 by West is Best

[Vikos]

Good morning

EC seems to be a bit more consistent

00z from yesterday -->

 

 

[mountain shadow]

So, a 1 or 2 day cooler spell with perhaps some frost on Christmas Day then back to chasing something interesting in FI.

Manyana manyana.