I'm not dreaming of a white Christmas...

[xmetman]

I'm not dreaming of a white Christmas...

Courtesy of www.netweather.tv

[Richard Dixon]

Certainly suggestions that things have tended towards a warming over time of the ensembles on "The Big Day".

Animation of 12Z 25th 850mb temps shows a progression northwards of that 0c line. That said it's still a 2 week forecast even today...

Richard

[Paul Garvey]

Hahaha! It's two weeks away! I'm not dreaming of one either, Bruce, but at this distance...

[Dave C]

It shows a mild trend but after a week or so there is the usual random scatter which generally means everything is possible but the default will be the most likely statistically. There was a date back at November 16th where the GFS 12z 850 hPa ensembles showed one tight cluster only, with the mean,control and operational all overlaid on each other for 10 days. There was also reasonable cross model support. (Don't worry Paul, I'm not nicking your ideas ;-)   )  . So I plotted the 850 hPa's for that period. They were very good, never more than a degree or two out for 7 days then the cold snap  arrived and they were way out after that despite a main though more varied single cluster then into the predicted uncertainty.

[Scott W]

Even in cold Decembers it nearly always warms up just before Christmas before cooling down again just after. This year will be no exception.

[Freddie]

2010 was!

--
Freddie
Fishpool Farm
Hyssington
Powys
296m AMSL
http://www.fishpoolfarmweather.co.uk/
https://twitter.com/FishpoolFarmWx for hourly reports

[xmetman]

I don't think we realised how truly exceptional that spell was, once in a lifetime kind of stuff.

[Freddie]

Oh I dunno - I remember 1981 as well :-)

[David Mitchell]

On Tuesday, 12 December 2017 20:21:01 UTC+1, Freddie wrote:

2010 was!

Or was it? We has consecutive "white christmases" in the East Riding, 2009/2010, with around 6 inches both times, but I don't recall a snowflake on the day, so it obviously wasn't white. 

[Freddie]

What Scott W said was that cold Decembers warm up on the approach to Christmas, and cool down again afterwards. I don't think white Christmas was mentioned...

--
Freddie
Hyssington
Powys

[Richard Dixon]

On Monday, 11 December 2017 23:21:11 UTC, Dave C wrote:

It shows a mild trend but after a week or so there is the usual random scatter which generally means everything is possible but the default will be the most likely statistically.

I think what we don't see - and what separates us on here from the forecasters - is the stuff beyond just the model output that bolsters confidence in what the models are producing in the long range - i.e. La Nina and how that feeds in winter patterns in early/late winter as well as what phase of the MJO we'll be moving into and the MJO phase's propensity (or lack of) for blocking round the UK - as well as the state of the polar vortex.

Richard

[Scott W]

2010 was very cold and there was snow on the ground (regarded by many as a 'white christmas'). But, because there was no precipitation on the day, it doesn't count.

[Richard Dixon]

Yippee!

[Scott W]

I can't find any bookies that is 'odds-on' otherwise I'd possibly lay a bet. What rubbish!

[John Hall]

On Tuesday, 12 December 2017 16:37:10 UTC, Scott W wrote:

Even in cold Decembers it nearly always warms up just before Christmas before cooling down again just after. This year will be no exception.

It happens often enough to have been named by climatologists as the Post-Christmas Stormy Period/

[John Hall]

The idea that a White Christmas has to have snow falling on the day was one promoted by bookmakers a few decades ago, who wanted something suitable for people to bet on. I continue to regard a White Christmas as one having a snow cover on the day, which seems to me far more logical.  

[John Hall]

I think it used to be more typical for the warming up to happen anywhen from the 25th to the 27th, so more often immediately after Christmas rather than before it. 1981 was a notable example.

[Richard Dixon]

On Wednesday, 13 December 2017 03:06:13 UTC, Scott W wrote:

I can't find any bookies that is 'odds-on' otherwise I'd possibly lay a bet. What rubbish!

I don't know: this looks 100% nailed on to me.

[xmetman]

Yes, perhaps that comment was a bit over the top!

My particular favourite was the Winter of 1978/79 in Sheffield.

And January 1987 in Lincolnshire.

[John Hall]

Talking of which, there's some good stuff about this and other so-called "singularities" in the British climate here. (There's lots of other very useful material on that site too.) 

[Trevor Harley]

I remember the winter of 1962-63 - just. I remember the first snowfall, and as it was the first snowfall I'd experienced I was amazed by it, and remember being amazed by it. I also remember my granddad putting up Christmas decorations on Christmas Eve, and they were the best decorations ever.

It wasn't my first weather memory though - I remember thunder and lightning in London before that, and also a dense London fog. Strangely it was the fog that made me most interested in the weather, wondering what on earth it was.

[xmetman]

Probably all the spiders webs it revealed in people's hedges...

[Trevor Harley]

Aren't we starting to dream a little bit after all?

[Dave C]

Talking of decorations, you can stick your LED front garden reindeers up your Arctic Pole - there was nothing more rewarding than licking and sticking those paper chains ;-)

[John Hall]

As a small child, assembling paper chains was probably my favourite part of Christmas - apart from the presents of course! Can you still buy them, or are modern children no longer enthralled by such simple pleasures?

[David Mitchell]

Indeed, very fond memories of paper chains.

[Dave C]

When my mum and dad got a bit more affluent we added to them with these kind of concertina paper lanterns that hung down from the ceiling. With an open fire we had some pretty good fire hazards by this stage! 

[George in Edinburgh]

Well, you can although the design has gone up-market. What a soft lot - double sided sticky tape indeed. There's a nice concertina ball for Dave C as well

https://www.dotcomgiftshop.com/paper-chain-kit-vintage-party

George in Edinburgh

[Len W]

Sure can still buy paper chains.
Just go down to Wilko.
Bought some for the grandchildren.

Only 3 colours though for the chain.

More environmentally friendly than LED chains but not the same impact.

http://www.wilko.com/search?q=paper+chains

Len

[Richard Dixon]

The GFS was a bit flighty at times with its "keep the snow lovers interested" winter parameterization in recent days but there's a broad agreement there now the EC ensemble mean data goes out to Xmas Day:

London's snow probabilities from the EC ensembles: