Model Output Discussion - Into Winter

[Hoghtonwhite]

Christ the lord that is some chart on the pub run. This is exactly what took place in December 2010. A cold front moved south preceded by a band of rain. What followed was freezing temps and instability everywhere with hefty outbreaks of snow moving here there and everywhereright down to sea level at coasts. The Irish Sea on the evening of Friday 17th December decided to plaster the north west with a foot of snow which lasted on the ground until well beyond Christmas with nightly minimums -12 Celsius through till Boxing Day. 

I just have a feeling it could happen again. 2010 isn’t that long ago in the grand scheme of things, considering all the noise around recent global warming. 
 

Anything can happen at any time. 

 

[alexisj9]

8 minutes ago, andy989 said:

I distinctly remember Kasim being jumped on for saying the cold air will be swept away easily. 

It wasn't swept away easily though, the cold stayed in place even while the uppers warmed, hence the freezing rainany got. It warmed after that though, but what happened to the real cold in the north east, scandi, not much yet, also part of the UK are still cold, and temps in many places are not cold enough for snow granted, but still chilly, and likely to stay that way till Friday. 

[Wold Topper]

Just now, alexisj9 said:

It wasn't swept away easily though, the cold stayed in place even while the uppers warmed, hence the freezing rainany got. It warmed after that though, but what happened to the real cold in the north east, scandi, not much yet, also part of the UK are still cold, and temps in many places are not cold enough for snow granted, but still chilly, and likely to stay that way till Friday. 

Thanks for clearing that up...

[Hoghtonwhite]

I think the GFS is sniffing something here. You don’t see charts like this often. 

[Snowy L]

1 minute ago, Hoghtonwhite said:

Christ the lord that is some chart on the pub run. This is exactly what took place in December 2010. A cold front moved south preceded by a band of rain. What followed was freezing temps and instability everywhere with hefty outbreaks of snow moving here there and everywhereright down to sea level at coasts. The Irish Sea on the evening of Friday 17th December decided to plaster the north west with a foot of snow which lasted on the ground until well beyond Christmas with nightly minimums -12 Celsius through till Boxing Day. 

I just have a feeling it could happen again. 2010 isn’t that long ago in the grand scheme of things, considering all the noise around recent global warming. 
 

Anything can happen at any time. 

 

This is good but 2010 was a whole other beast. That PV chunk over Scandi on your charts was actually over the UK in 2010, dropped directly down from the North Pole. It's what allowed a rare westerly lake effect event for Northwest England.

 

Won't be seen again for a very long time imo, but will make do with what the GFS 18z is offering

[Cheshire Freeze]

That’s some N’ly at the end of the GFS. A part of the trop vortex drops into Scandi…beautiful. Over the past few years it has been the other side of the pond seeing that!

Air mass wouldn’t be too modified under and around that either. Severe cold if something like that occurred.

Edited December 4, 2023 by Cheshire Freeze

[Hoghtonwhite]

1 minute ago, Snowy L said:

This is good but 2010 was a whole other beast. That PV chunk over Scandi on your charts was actually over the UK in 2010, dropped directly down from the North Pole. It's what allowed a rare westerly lake effect event for Northwest England.

 

Won't be seen again for a very long time imo, but will make do with what the GFS 18z is offering

Thank you for clarifying. Yes it definitely did feel like a lake affect snow event, as it was hardly forecast. Only the US can forecast lake affect it seems . 
 

unfortunately during most cold spells, we just don’t get the temperatures low enough. Otherwise north west England would be prime position whenever we get a westerly during cold spells. 

[Metwatch]

9 minutes ago, Hoghtonwhite said:

Anything can happen at any time.

With that logic winter months milder than December 2015, January 2007 or February 2019 could also happen

Edited December 4, 2023 by Metwatch

[Hoghtonwhite]

Just now, Metwatch said:

With that logic winter months milder than December 2015, January 2007 or February 2019 could also happen

Yea although one would say we are now due the opposite. (Hopefully).

[damianslaw]

1 minute ago, Hoghtonwhite said:

Thank you for clarifying. Yes it definitely did feel like a lake affect snow event, as it was hardly forecast. Only the US can forecast lake affect it seems . 
 

unfortunately during most cold spells, we just don’t get the temperatures low enough. Otherwise north west England would be prime position whenever we get a westerly during cold spells. 

South Cumbria just experienced a lake effect snow, and temps were at or above freezing. No deep cold needed.

GFS18z on one tonight, or is it spotting the evolutionary pattern right. It can often do so when it comes to northerlies, probably be gone tomorrow and then reappear again, dropped again, back again...

[Cheshire Freeze]

1 minute ago, damianslaw said:

South Cumbria just experienced a lake effect snow, and temps were at or above freezing. No deep cold needed.

GFS18z on one tonight, or is it spotting the evolutionary pattern right. It can often do so when it comes to northerlies, probably be gone tomorrow and then reappear again, dropped again, back again...

The back end of the GFS runs will probably need to be followed now as they take us out to the next period of interest.

[Dignity]

Is this GFS sniffing out the start of the trend way out before the flip flopping happens?

Would be lovely if it verifies!

[minus10]

Incredible 850 temp anomalies being modelled over Baffin Bay, north west passage and western Greenland ...

[The Enforcer]

17 minutes ago, Hoghtonwhite said:

I think the GFS is sniffing something here. You don’t see charts like this often. 

Not at T+0, but at T+388? All the time.

[Allseasons-Si]

I have been watching the gefs control run coming out and i think that it might do a run similar to the op,...here at 300 for comparison.

[Scott Ingham]

Looking at that profile in the outer reaches two things appear plausible.

1) The Uk high (MJO 7) 17th. 7 days after the phase is reached on the 10th. High enough amplitude to be 7-10 days including lag which then leads to (MJO 8). 
The Greenland high. 

2) The polar vortex pushed away from Canada 2-3 weeks from the Canadian warming! 

What a set up eh? Northern Heights to our west and incredible cold to our north east (the massive low over scandi is a piece of the polar vortex. Extremely similar to 2010!

The danger could be a west based set up over time with the polar vortex pushed away from Canada and Greenland but that’s too much detail to worry over for now!

[Bricriu]

I'd take a west based nao, provided we got a dumping of snow beforehand.  With that set up there would surely  be a polar low or two popping up to do just that. Let's hope this is the GFS sniffing out a new trend and the other models will follow it- just as we saw with this soon to be departed cold spell  

[Windysun1]

I dont think anyone would be interested. Bit marginal! ; )

La la land but be nice if it got support. Although would not be far off some back ground signals. See what the morning brings.

Just noticed those..those high pressure reading are extroardinary. Interesting.

Edited December 5, 2023 by Windysun1

[Windysun1]

28 minutes ago, Windysun1 said:

I dont think anyone would be interested. Bit marginal! ; )

La la land but be nice if it got support. Although would not be far off some back ground signals. See what the morning brings.

Just noticed those..those high pressure reading are extroardinary. Interesting.

A Dickens winter indeed..maybe throw in a frost fair. Silly hour now good night folks.

[KTtom]

GFS day 10 has the blocks firmly in place which generalise a typical UK mid-winter..High pressure to the south and a solid slab of PV to the north west. The UK situated on the fast running weterly highway in between. This is going to be a bit more than a mild 'blip'.

Edited December 5, 2023 by KTtom

[Vikos]

00z hangover after 18z Pubrun?

 

[nick sussex]

Some ugly looking charts for coldies barring the ECM which wants to try and squeeze a ridge ne towards Scandi day 9 into 10.

Unfortunately the attempt fails . 

You really need that deep troughing to remain sharp , so that the jet can bounce ne and then back sw .

Day 9 gave some hope which sadly didn’t materialize as any dig into the Atlantic is lost as the pattern flattened day 10.

 

Barring the Scandi high longshot it’s looking pretty grim for coldies .

[Gowon]

That cold air doesn't fully budge over Scandinavia - Watch how the energy from the lows break up as it bumps into it:

  

Edited December 5, 2023 by Gowon

[Nick2373]

00z there looks to be some sort of trend setting up from around the 14th i think we'll see a dryer spell with temps just below or average for the time of the year.  

[IDO]

The trend we saw in FI late last week for the tPV to shift back to our NW looks like it was forecast correctly. So D8-16 mean:

Obviously this restricts the colder options for the UK. When this sets in, it is usually for a while unless interrupted by background forces. 

The forecast of an Atlantic ridge (weekend) looks like the models usual bias of over-playing heights, so UK heights maybe the best we can expect as that Atlantic high pushes east. The more likely is a return to the classic Winter, low pressure to the NW and the Azores high: a NW to SE flow at times...zonal.