So, to kick things off - hours of heavy snowfall in Tokyo (around 12 degrees below average). Until this morning it was just forecast to be rain at 4C, but it's been upgraded to snow in this morning's run.

http://www.metoffice.gov.uk/public/weather/forecast/xn76vrqe1#?fcTime=1479945600 

Hopefully we don't see a repeat of what happened frequently in the 2000s; HLB unable to develop so HP ends up ridging SSW out of Russia and Greece/Turkey/N Africa get snow

You're omitting Dec 2009, where a large area of the country got decent lying snow before the 20th, lasting until beyond the 26th. Of course, it depends on one's definition of 'prolonged', but a week+ is very good for the UK.

But if it's any consolation, Verkhoyansk, in Arctic Siberia, one of the coldest inhabited places on Earth, hit 19.2c last Friday


http://siberiantimes.com/ecology/casestudy/news/n0793-no-global-warming-in-siberia-donald-trump/

So we probably don't want much Siberian air just yet

UK Outlook for Thursday 8 Dec 2016 to Thursday 22 Dec 2016:

After an unsettled start to December, the rest of the month is likely to be calmer overall. High pressure is expected to dominate, especially in the north and east, leading to drier than average conditions. Interludes of more unsettled weather are expected to be fairly limited, though these could still lead to some snow. Whilst it may be relatively mild at times, temperatures on the whole through this period are likely to be below average.

Updated at: 1315 on Wed 23 Nov 2016

The latest METO update.Still sticking to its guns ie HP taking over after an unsettled start.They mention HP dominating particularly in thei the north and east.

Question where would HP centre be located -sometime to the north and sometime to the east  or generally to the north east.?The exact position has a huge impact on the temperature of the air flwing over us.

Another question when is the next METO contingency forecast due?

It usually comes out a couple of days before the end of the month so probably Monday or Tuesday next week. But it can vary.

"Forecast Background

From the outset this has been an incredibly difficult forecast to work through, with multiple variables this season that are outside expected parameters. In essence, it is a winter where wildcards are in abundance.

Temperatures - Front Loaded Cold

During December and January, there is a greater probability (60%-70%) of colder than average conditions as high pressure systems become situated in, around and particularly to the north of the UK. This points to an increased risk of cold air masses originating from the north or east affecting the UK. A lower likelihood outcome is that temperatures during this period will be close to average, but even so, relatively cold conditions can be expected at times, and especially so when compared with last December and January. There is the potential for a change to milder conditions later in the winter, but this is an uncertain development at the current time.

Rainfall - Dry First Half, Potentially Becoming Wetter Later

The overriding signal this winter is for a greater chance (>75%) of slightly drier than average conditions during the first half of the season. This is due to the expectation of frequent high pressure and 'blocking patterns'. This signal is in contrast to last winter, with December expected to be very different to the exceptionally wet and windy December of 2015. There may well be a recovery in precipitation totals to nearer average through February and the latter half of the winter in general, but given the time frame involved this is an uncertain development, with a lower likelihood (>25%) of drier conditions continuing throughout the winter period."

http://www.netweather.tv/index.cgi?action=longrange;sess= 

All the best to Tony and Matt with that forecast, Tony doesn't have the best of records over the years (apart from predicting a couple of pretty obvious mild Decembers) when doing it with Chiono so we shall see how this partnership does.

The key word is "drier." than average.I have posted elsewhere that I think the most likely cold spell is mid December and marked by frost and fog rather than shed loads of snow.

In H.H Lambs classic book "The English Climate " written in 1964,he identified singularities being periods of weather that appeared more regularly than not. December split into 

Early winter storms  26/11-10/12  Winter return of the westerlies after autumn anticyclonic episodes.

December Continental Anticyclones  17-24 Dec -Before Christmas frosts dryest period of December.

Storms of Mid Winter  26 Dec.-12 Jan 

So December Continental anticyclone is the most likely weather type for  a possible winter cold pell this year.

It is also true to say that rarely is there prolonged prolonged snowy spells in December.Of course there was 2010 but before that only 1981 really had prolonged snow cover. Earlier than that  only December 1961 come to mind with a two week cold cold spell from around Dec 20th.

There are occasions when a cold snowy  spell set in around Christmas and then persists  into a cold January.Into this category comes December 62,December 78  and December 85.

December 1970 was a good snowy Christmas for me.
Do Lamb's theories hold up statistically in the last 5 decades?

I must say, after being quietly confident for this winter following early pronouncements by the Met Office & BBC, my faith is shot through now.

It's not because current NWP is poor (it flips about like anyway), but rather that the semi-permanent HLB which was forecast to be in place for the first half of winter at least and be the driver for feeding generally cold conditions to the UK is being shown to diminish to such a point it has little or no influence on the UK, whilst crappy lows just barge through at will.

Bertwhistle I believe that original classification had some criteria for regularity of occurrence but i think that criteria related more to Germany (the Flohn and Hess criterion ) than the UK.

Given all the failures to find significant links between weather types and analogue years i doubt very much that  the is any significant link over the last five decades. Have a look at Appendix 1 of The English Climate and see what you make of it.!

Yes 2009/10 was excellent here. Snow lay from the 17th December and lasted for 30 days at sea level. The river began freezing for the first time since 1995. Inland at my family home at 100 Mtrs asl there were 75 snow lying days over the Winter with the best falls being 40 cms on the 27th Decmber and 30 cms in late February.
Meanwhile this year it looks like a UK high may well be in place in mid December. Ok dry and cool but a waste of possible snow time by that time of year if it hangs around.

Someone posted that recent winters have seen the really cold weather going off down to Greece and the Med, instead of staying north where it 'belongs'. (might have been in the model thread - can't find it now)

Anyway, here we go again

http://www.wxmaps.org/pix/temp4.html

So here’s my final prognosis on the upcoming Winter 2016-17.

I’ve used 6 different indices to try and determine the Winter outcome, these being ENSO, Solar cycle, QBO, North Atlantic SST profile, PDO and the November 2016 synoptic anomalies. I dropped two other elements, (1)the October synoptic anomalies, because there were only 2 matches overall !!, and (2) the October AO index, again because there were too few decent matches. So from all these, here’s my thoughts:

December 2016
What I found striking was that all indices are pointing to a High Pressure anomaly in the mid-Atlantic and towards the Azores, with a chain of Low Pressure anomalies stretching from Iceland to Scandinavia. So, Low Pressure areas are likely to swing down from near Iceland on a NW-SE trajectory, and occasionally bringing some colder interludes, especially for the NE of the UK. However, due to a dominant W-SW flow, December looks to be slightly milder than average, and also a little drier than average too.

January 2017
The general theme seems to be an encroachment of the Russian High westwards somewhat, and also a build of High Pressure over the Arctic, although no major blocking is indicated. Some signals also for a weak Low Pressure anomaly over Europe, and still a mid-Atlantic or Azores High signal, though less strong by then. The net result looks like being a near average month for both rainfall and temperatures, with no one weather type dominating this month. Probably a real mix of Atlantic spells, some Anticyclonic set ups, and the risk of a few colder spells from the north and east.

February 2017
This is where there is a definite divergence of what the indices are suggesting. In fact there is a straight two-way split between what the Oceanic indices are indicating (ENSO/PDO and Atlantic SSTs), and what the Solar/QBO and November analogues are saying. So we have the Oceanic indices suggesting a fairly benign February with a lot of High Pressure stretching from the mid-Atlantic, through to the UK and into Northern Europe, giving us a fairly settled, dry, and near to average month for temperatures. However the other indices suggest more of a Northern High Pressure block setting up, Low Pressure over the Med, and with a definite easterly anomaly into the UK resulting in a colder month. On balance, I think it will be more a mix of the two scenarios, but perhaps more favouring the benign option. That still gives us a February with a decent chance of some colder, wintry weather, but probably for much of the time, February will be fairly uneventful, settled and dry with temperatures near normal.

WINTER 2016-17 SUMMARY
The Winter overall is likely to be near average to slightly mild, and with rainfall a little below average generally.

http://www.bbc.co.uk/weather/features/38122653 

I've issued my full winter forecast on my blog. Here I'll just post my thoughts for each of the three winter months:

December

Out of all three winter months, I am forecasting December to hold the best chances of colder weather for the UK. It appears as though this month could actually be a very anticyclonic month, with an area of high pressure centred quite close to the UK. Of course at this time of year, this would produce cold conditions at the surface due to temperature inversions. This means that many parts of the country will see a fair amount of frost and fog this month. Furthermore, this means that I also predict the month to be rather dry.

It is also worth noting that there is a chance that this high pressure system could possibly move westwards out into the mid-Atlantic, on some occasions. This would have the effect of bringing a northerly wind down across the country, which could increase the chances of snow and harder frosts, even for southern areas of the country.

January

I am forecasting January to be somewhat of a transitional month, with colder conditions being more dominant in the first half, before more of a milder Atlantic flow increases in the second half. In terms of individual weather, this means that this month could actually be very varied. There is the potential for some cold and snowy weather early on, followed by an increased chance of more stormy weather later on. I expect temperatures to overall come out very near to average, with northern areas being more prone to colder conditions and more southern areas being milder. Rainfall, I predict to be very near average in eastern and southern areas, whilst northern and western areas will see the wettest conditions.

February

Obviously confidence does naturally fall away for later in the season, but as of current, I am expecting February to be the mildest of the three winter months. Here I expect any UK blocking to collapse into Europe and for a predominantly west-to south westerly flow to set up nationwide. In February I expect both temperatures and rainfall to be above average especially for northern and western areas, with south-eastern areas seeing the driest conditions, closer to the Euro high. I also wouldn’t rule out some northern areas seeing some potentially stormy weather at times.