On the other hand, if the blue crosses in the right-hand diagram at the bottom left of that pdf are meant to indicate the outcomes of various model runs for Oct/Nov/Dec, then the scatter is so wide and equally spaced that a better statement might be "anything could happen at that range, how should we know?" I honestly wouldn't have any problem with that.

But I do take their point that if they're more confident in the near term (Oct) having above-average temps, then by extension Nov and Dec should be below-average for the overall result to be average.

I would like to see them reveal more of their workings though. Clarity as to where those blue crosses derive from would help, though it might well be clear and that's just me being thick.

The document isn't intended to provide that level of detail, as the intended audience are contingency planners, for whom the probabilistic outcomes are useful. However, the propensity for colder solutions, as described through Nov-Dec, have been based on (continuing) GloSea5 signals (including stratospheric modelling). Glosea ENS members drive the blue crosses you mention. Coupled to the UKMO modelling is broad support that's emerged from the other key seasonal models given higher weighting in UKMO Seasonal Team assessments (principally ECMWF Seasonal, which is due to update 8th Oct; and MeteoFrance's Arpege-Climate... the combined output from GloSea with those other two centres creates the EUROSIP model via ECMWF). UKMO Seasonal meetings each month then examine all this collective output (plus from other nations) after which the contingency planning document is written. Cheers.

Quite an escalation of snow cover over siberia

For reference - 2015

Many thanks. I wouldn't have posted in such a sarky manner if I'd known I was going to get such a useful and detailed reply!

So the blue crosses are no more than a reflection of the various runs of the Met's GloSea5 model, while the conclusions reflect the combined probabilities of that model plus all the other inputs you list. 

I feel a lot more comfortable about the possibility of an average or colder-than-average Nov/Dec period after that. (While bearing in mind milder than average is still a possibility too of course - the number of blues crosses from the GloSea5 model in that area of the scale make that unavoidable.)

It really depends on what sort of 'average' is being discussed - with 20 of the last 29 winters containing 2 or 3 DJFs that were above average, then an 'average' winter based on the longer term averages would be cold relative to the modern era.

That's a very good point. What do the Met Office mean by an 'average' winter. In my experience most winters in lowland England either bring little or no snow, or several accumulating falls of snow. Basing a definition on temperatures doesn't cut the mustard either because that could mask cold and very mild periods.

How can you tell a if there is gong to be a significant snow event this far out?!

An example:- anyone who was around Yorkshire in late January 1995 will remember the huge wet snowfall they got. That was a significant snow event in a very mild winter.

There is no way you can tell if there is going to be a significant snow event this far out.

Isn't that just saying though that 'we have haven't the foggiest?" As said above, 'average' can cover a lot, or very little, depending on your view point. To me, an 'average' winter just means some wet spells, some dry spells, some mild and some cold. Sorta what happens every winter really.

its the same thing in my book.

Top forecasters are paid an awful lot of money to put their neck on the line. Either do it properly or say nothing. 

1) I'm not sure they're paid an awful lot of money

2) They are paid (unless you're referring to the more esoteric ones) to analyse the data from computer models and background signals and then reach a logical conclusion, not give their subjective opinion. There is a place for the latter IMO but it should be clearly separated out from the data based forecasts.

I think there is a very good chance I could see the heaviest snowfall in years this winter.

All I need is half an inch of level snow lasting a couple of hours

Half an inch?  Pah! All I can do is dream about half an inch!  A dusting would be the heaviest snowfall for years.

Siberian snow cover continues to grow

Current ^ much better than last year, but on par with the previous years before then  2012 also a standout poor year at this stage.

2015:

2014:

2013:

2012:

So TWO is a long range forecasting site according to the Bristol Post

However, support for the initial forecast comes from The Weather Outlook, another long-range forecasting site, which said a range of factors meant there were strong suggestions a colder and potentially white winter was in store for people across the country.
Read more at http://www.bristolpost.co.uk/forecaster-warns-people-in-bristol-should-be-hunkering-down-for-four-months-of-snow/story-29765880-detail/story.html#JY13ZDzJv4O6s2Up.99

Don't you just love it!!

What's Matty been telling them?

Fancying some warm, golden autumn weather, I was musing at the charts for the end of the first week of October. I thought the predictions looked rather like October 2010, and even the Friday seemed to have the happy 20 degrees that the Friday in 2010 had. Totally unscientific (not spectacular, but it felt warm on the day). Then I remembered how it worked out 6 weeks later. I got excited for a moment.

Accuweather has released a preliminary winter forecast for the States and overall it looks cold for the north and warm for the south with frequent storms for the east coast. Hard to judge if this would indicate a more positive or negative NAO for the N. Atlantic though.

http://www.accuweather.com/en/weather-news/2016-2017-us-winter-forecast-northeast-above-normal-snow-freeze-hurt-citrus-south/60277878 

http://www.msn.com/en-gb/news/weather/uk-weather-britain-faces-four-months-of-snow-as-forecaster-predicts-long-winter-with-sub-zero-temperatures/ar-BBwQz7J?ocid=spartanntp

I'm hoping they are not referring to this 'The Weather Outlook'- never known TWO to make such tabloid-hype-like statements or long-range pretences in such an assertive & extreme way.

See Brian's "Mirror Comments" thread. 

As Ben says, have a look here http://www.theweatheroutlook.com/twocommunity/default.aspx?g=posts&t=16881 

I suspect the comments may actually have originated from another forecaster not associated with TWO who has "form" with this type of hyperbole.