Re: the current output...

Whilst I'd love a really prolonged period of overall cold to last from late November well into the second half of winter, that's hugely unlikely. Even the amazing 2010 spell only managed to last until late December (not even that in some more southern areas). I've seen a few winters with a sprinkle of early promise dissolve into a mild and wet borefest.

I'm hoping (not that this makes any difference) that this late Nov chilly spell is just a scene-setter. We've had plenty of periods over the past couple of decades where the weather has 'got stuck in a rut', or a recurring general pattern. Not usually that favourable, but it's a theme - and something mentioned by climate experts as likely to be more common with climate change. A winter of recurring blocks to our NW/N would be very welcome.

Mid-November has turned out more interesting than I was anticipating, but not in terms of the immediate weather, rather the bigger picture.

Long story short, I've been noticing some sacrificing of the potential depth and persistence of cold weather across the UK in the final third of November, in exchange for increased potential in Dec generally, via raised likelihood of blocking patterns that also have more potential to disrupt the polar vortex.

Notably, blocking highs across the Urals have begun to appear in some model projections for late Nov / early Dec. This has been majorly missed in the past fortnight, as it's a key instigator of stratospheric warming events.

During a La Nina December, an inherent tendency for high pressure to locate west of the UK means that only a weakened polar vortex is required to open the door for some notable -NAO episodes; we don't need a SSW to do the trick.

Uncertainty is still considerable, mind. Especially with the La Nina having changed shape a little in the past week, the largest cold anomalies now being focused in the eastern rather than central Pacific. This takes it away from the 'classic' La Nina configuration and reduces support for a -NAO in Dec while considerably increasing it in Jan-Feb.

That could prove a major wildcard for this winter, if the largest cold anomalies remain in the east Pacific. Also uncertain... the joys of long-range forecasting!

Mid-November has turned out more interesting than I was anticipating, but not in terms of the immediate weather, rather the bigger picture.

Long story short, I've been noticing some sacrificing of the potential depth and persistence of cold weather across the UK in the final third of November, in exchange for increased potential in Dec generally, via raised likelihood of blocking patterns that also have more potential to disrupt the polar vortex.

Notably, blocking highs across the Urals have begun to appear in some model projections for late Nov / early Dec. This has been majorly missed in the past fortnight, as it's a key instigator of stratospheric warming events.

During a La Nina December, an inherent tendency for high pressure to locate west of the UK means that only a weakened polar vortex is required to open the door for some notable -NAO episodes; we don't need a SSW to do the trick.

Uncertainty is still considerable, mind. Especially with the La Nina having changed shape a little in the past week, the largest cold anomalies now being focused in the eastern rather than central Pacific. This takes it away from the 'classic' La Nina configuration and reduces support for a -NAO in Dec while considerably increasing it in Jan-Feb.

That could prove a major wildcard for this winter, if the largest cold anomalies remain in the east Pacific. Also uncertain... the joys of long-range forecasting!

Fascinating stuff, SC, thank you. I hadn’t appreciated the subtleties within a La Niña pattern; always assumed it just favoured a colder start to winter and milder later.

I would quite happily trade a cold spell at the start of winter for something more durable in January and February.

Part Two of the eleventh winter 2021/22 update on Monday was an ENSO/La Nina special 

Part Two of the eleventh winter 2021/22 update on Monday was an ENSO/La Nina special 

 

 

👍👍👍 Top man Gavin P

 

👍👍👍 Top man Gavin P

Thanks so much my friend. Was an interesting video! 

Looks like it's going to be a mild winter ...... or a cold winter 


https://www.dailymail.co.uk/news/article-10224851/Its-weather-wars-Met-Office-forecasts-mild-winter-BBC-predicts-big-freeze.html 

Over the last few weeks there has been an obvious tendency for the synoptics to resemble the synoptics often seen in the 60's,70's and early 80's.

The MeteoGroup in its winter forecast for November onwards sees 'a weak polar vortex' leading to a ‘cold, dry and calm winter’. The Met Office concentrates on climate change influencing the outcome and bets on a '60 to 80 per cent chance of above-average temperatures across December to February'.

The last few weeks has seen weather indicators which favour the MeteoGroup's outlook.

We have seen -    

                              synoptics suggesting a weaker polar vortex  

                              high Pressure building in the North Atlantic without the ridge into Europe leading to more NW'ly winds

                               ............rather than SW'ly

                              the rapid growth of Arctic Ice cover after a very warm October along the Russian Arctic coastline

                              record snowfallsand temps? in China.

                              record low temperatures in Siberia

                              and......

                              Record Snowfall reported today 25th Nov. in Hokkaido, Japan

                              and.....

Place you bets!

My money would be on a changeable winter, with any cold spells being brief (under a week)

My money would be on a changeable winter, with any cold spells being brief (under a week)

I think presently I'd have a £10 bet each way.

...and you could well be right, Saint!

It's a sign of the times that we get so aerated about the possibility of a snowy late November day!

R

Following all of this closely - I think we'll have to wait til January for a good cold spell.

This December is showing signs of being colder than what we've had for some time - But don't get carried away.

The last week of the month may make a change.

Apologies - I've seen this mentioned somewhere, but can't locate the thread. Mods - please feel free to relocate this.

We've just watched Chris Packham's Winterwatch showing of a classic documentary from the BBC's archive, which takes a look at the worst winter of the 20th century in 1963. It was 60 minutes well spent - strongly recommended if you have not seen it.

1963 - The Big Freeze
https://www.bbc.co.uk/iplayer/episode/b01q9d86/winterwatch-1963-the-big-freeze

Roger

1962-63....now that was incredible..will we ever see the like again? 2010 was about the closest we have got in recent decades and that was nowhere near the impact of the Big Freeze. Mindblowing black and white film footage of that simply unthinkable winter. Well worth watching if you missed it!

Was chatting with my Mum via Skype yesterday and she was born in 1940. She clearly remembers 1963 but also the winter of 1947. They were so far removed from modern British winters that it's not even funny!!

I've given up on this winter now.

Not saying 'winter is over' and there may well be some snow to come, but all enthusiasm has drained from me.

I still say, also, that snow and cold in the lead up to and over Xmas is the nirvana.

But I'd also love to experience a real snow-mageddon event, with at least 30cm of snow over the whole country, which would be totally paralysed for several days.

I've given up on this winter now.

Not saying 'winter is over' and there may well be some snow to come, but all enthusiasm has drained from me.

I still say, also, that snow and cold in the lead up to and over Xmas is the nirvana.

But I'd also love to experience a real snow-mageddon event, with at least 30cm of snow over the whole country, which would be totally paralysed for several days.

My thoughts exactly but sadly not this time around