Model Output Discussion - Winter arrives

[tight isobar]

Siberian lobe is the daddy.. and wants to drain mummy’s resources .. from here it’s cold spilling into the mid latts  and no prizes for what sector is prime.

Edited November 29, 2021 by tight isobar

[I remember Atlantic 252]

Just now, Penicuikblizzard said:

The uppers don’t look especially cold over the UK in these runs -4c - -6c so cannot see it being widespread snow apart from high ground…..cold rain for many

Okay for sliders/fronts, but not for anything convective

[Penicuikblizzard]

2 minutes ago, Allseasons-si said:

Holy sheet!!!!,...at 216

Just need those bitter temps to cross the North Sea then bingo  

[sheikhy]

Low thicknesses!!slack air flow!shortest of days!perfect for snow and freezing temps!!

[Man With Beard]

Bit of a snow dream this ECM - southerly tracking jet with channel lows ... don't be fussy coldies, this is good stuff for the first week of December!

[Allseasons-Si]

On 29/11/2021 at 18:52, Penicuikblizzard said:

The uppers don’t look especially cold over the UK in these runs -4c - -6c so cannot see it being widespread snow apart from high ground…..cold rain for many

 

On 29/11/2021 at 18:52, sheikhy said:

Not mega cold uppers but the ecm is the exact kinda run that brings copious amounts of snow!!

Don't need to be in battle ground scenarios or sliders into cold air.

 

[Panayiotis]

-4C to -6C 850hPa in that setup on the ECM can deliver snow for most of UK. Very cold for Scotland, possible for -20C over the snowfields.

Edited November 29, 2021 by Panayiotis

[Man With Beard]

3 minutes ago, I remember Atlantic 252 said:

Okay for sliders/fronts, but not for anything convective

The slider will keep a few people happy 

[Tim Bland]

Just for fun of course but… A SOUTH of the M4 event here ️

[Ali1977]

Great ECM, now let’s see what the ENS mean shows at around 144 

[Ali1977]

Just now, Man With Beard said:

The slider will keep a few people happy 

Yep, I’d take that

[carinthian]

11 hours ago, carinthian said:

Morning all. Still the snow piles up over here, 35 cm just measured and temp down to -6c ! Just an update  follow on from the above post.  The  extended period UKMO run I been following for Friday morning continues to hold the disturbance even further west this morning with any snow reserved for the Welsh /Irish mountains. This is an correction westwards as the colder air close to Eastern Britain continues to intensify towards the next weekend. So broadly looking at this mornings models, I think there is a good chance or even surprise snowfall events in the making. The ups and downs shown in the operational runs still trying to work out the cold/ milder scenario in the medium/ longer term. However, even in the shorter term there will be many corrections this coming week just as I have highlighted with the chart for Friday below. Cold lover keep the faith. Think UKMO met office updated fax runs may hold the key in the 96h -120 shown later today.

C

Evening all , just an update from the above post earlier this morning. Of course all the attention is on the post 144t charts looking for an upgrade in  cold potential or not but as we can see in the updated fax for Thursday, even in  the short term an upgrade is possible. That chart below now has the triple point location on the frontal system approaching the British Isles further south than previously plotted with a tighter squeeze on any warmer sector. So transient snow could occur across the spine of the country on Friday, even towards Southern Counties for a short time but amounts should not be too great. The wave along the frontal boundary could be more interesting over the weekend as it tracks across Southern Britain. Its exact track could determine the areas that could get some wrap around snowfall as it moves into the North Sea. So a lot to play for and as I report in the above post surprise upgrades are in the offering as the week progresses.

[MATTWOLVES 3]

I'm liking this..just check out the eye of Heights over the Arctic...and we also see Heights attempting to spread into East scandy come the end...Im sure the 87 cold snap had the Heights pushing out of Russia towards scandy...then boom...frigid air was on tap to the NE...and its pretty rare to be seeing such intense cold there at this stage...

Again are the met missing something...or are us lot barking mad.

Tell you what folks...tonight's EC46 is gonna be a pressure cooker situation...any takers for the updates...I may be hiding behind a very large curtain

Edited November 29, 2021 by MATTWOLVES

[swfc]

Northwestsnows wedges have gone into snorter drive. That said keep that powder dry EC was binned not so long ago

That said Ec and the nhp look pretty awesome for early December. 2 snowfalls in and its got a late 70s early 80s feel and look to it. Uto

[Mike Poole]

Well that was fun!

Just wanted to pick up on differences between the ECM and GEM back at T96, as it may be relevant to the amount of uncertainty we are seeing.  The upstream low (ECM) or lows (GEM) quite different.  Bound to have an impact later in the run.

 

[Kasim Awan]

7 minutes ago, Panayiotis said:

-4C to -6C 850hPa in that setup on the ECM can deliver snow for most of UK. Very cold for Scotland, possible for -20C over the snowfields.

Ice days in places imo with such low heights, slow moving heavy snow events producing widespread snow cover and light winds. 

[tight isobar]

The gfs toyed with Canadian lobe separation, to shunt progress on any heights exeling. And can be forgiven.. as will look certainly for bk to default. As a mobile king!.. It’s the Atlantic prog model by way of design.. anyway, I think we’ll see the decipher- and revert in its nxt suite &@18z- if not for sure it’s 00z run.

Edited November 29, 2021 by tight isobar

[Man With Beard]

10 minutes ago, MATTWOLVES said:

I'm liking this..just check out the eye of Heights over the Arctic...and we also see Heights attempting to spread into East scandy come the end...Im sure the 87 cold snap had the Heights pushing out of Russia towards scandy...then boom...frigid air was on tap to the NE...and its pretty rare to be seeing such intense cold there at this stage...

Again are the met missing something...or are us lot barking mad.

The issue for me is getting onto the right trajectory. At T120 it looks promising to get the southerly tracking jet, but it still looks like it could go either way, and that would have implications for the area you mention. If the ECM/UKMO still show the same charts tomorrow at this time, we'll be in a much better position to call another snow conducive spell and potential block that you show here.

Edited November 29, 2021 by Man With Beard

[sheikhy]

Difference occur between ecm and gfs at only 96 hours near the eastern states with that low!!the facts are the ecm trumps gfs at that time frame all day long if we go according to history!!!

[bluearmy]

What’s not to like ?

Bit concerned that it’s ec op which amplifies enough to create a stonking Svalbard wedge but we’re not taking the run as gospel

Note the polar profile late on as the Canadian segment begins to send its low heights back towards its Asian parent - crucially the other side of the pole. 

Plenty of swings and roundabouts still to go through but it remains more than interesting ! 

[danthetan]

I would love to see the Dewpoints and surface temperature's but that looks like a very snowy run from the ECM. Enough moisture to produce precipitation and cold enough air to undercut. Scandinavia being so cold is a big help with this pattern.

[JBMWeatherForever]

Yes those upgrades almost in the short term on the UKMO FAX run are sign posting the charts we are now seeing further out. The pendulum seems to be swinging toward a more prolonged cold outlook. And given those synoptics a snowy outlook for the UK next week too. Also getting such deep cold in place to our N E so early bodes very well indeed.     

 

 

 

Edited November 29, 2021 by JBMWeatherForever

[Ali1977]

9 minutes ago, danthetan said:

I would love to see the Dewpoints and surface temperature's but that looks like a very snowy run from the ECM. Enough moisture to produce precipitation and cold enough air to undercut. Scandinavia being so cold is a big help with this pattern.

-10c showing by 10th Dec in Wales , with temps staying well below freezing in the day time 

 

 

Midday temps are very cold 

Edited November 29, 2021 by Ali1977

[SqueakheartLW]

Even the dreaded CFS is now sniffing out an easterly next week would you believe it

Yes, I repeat, the CFS is SEEING THE EASTERLY TOO

Here's the 06z run from Thursday 2nd onwards to the 12th but by the time we get to the 12th we can say for sure things will very likely change before then

Thu 2nd Dec

Fri 3rd Dec

Sat 4th Dec

Sun 5th Dec

Mon 6th Dec

Tue 7th Dec

Wed 8th Dec

Thu 9th Dec

Fri 10th Dec

Sat 11th Dec

Sun 12th Dec

 

I know it's the CFS and it's probably having one of its ...

Computer Fantasy Scenario

moments but you never know, it may be onto something here

GEM 12z

Couldn't help but see the decent GEM 12z Op run too

Thu 2nd Dec

It does go onto a less cold blip before it turns colder and colder as it progresses and ends like this

Thu 9th Dec

 

Having said that P9 from the GEM 12z is also a decent cold member too

[blizzard81]

1 hour ago, tight isobar said:

Looks like a snapshot - of where the GFS was the 1st mod to churn out these very Synoptics!!!

Absolutely. The gfs first spotted this and was like a dog with a bone about it. Quite a few were too quick to disregard the gfs just because ecm and mogreps didn't agree. However, the ukmo op runs were leaning towards the gfs ops over the last couple of days. Ukmo has now jumped into bed with the original gfs prognosis along with the gem and now ecm. Kudos to the gfs. Two decades of model watching has taught me one thing. Although very erratic at times, the gfs has also had a habit of picking out these amplification events and correctly stuck to it. Every dog has its day as they say and the gfs has had more of these than what it has ever been given credit for. Yes, tonight's op has taken a step back somewhat but it isn't a full on backtrack. I will say one thing here. The ecm op has been playing catch up big style these past few days.