One thing I noticed while following the detailed explanations of the teleconnections involved in long range forecasts both here and over on Netweather last winter is that there seemed to be so many potential variables that I'm not entirely convinced of the point.
It seemed to be that present conditions would give rise to such an outcome in 3/4 weeks time. Fair enough but it usually seemed that a week later those present conditions, or at least one of those factors driving those present conditions had changed so considerably as to totally alter the outlook.
No disrespect to any long range forecasters because I really admire the knowledge and work that goes in to those forecasts and I really enjoy reading them. Are there just too many variables to make anything other than a very broad brush forecast for a wide area?
I'm not saying I'm right btw, just how it seemed to me.
I think the best we will ever do is identify conditions which raise or lower the probability of deviations from your standard weather over a 3-month period.
The problem is how few of those there seem to be. Being at the bottom of a solar cycle, or better still, just coming out of one, seems to increase the chance of a cold winter. So does an easterly quasi-biennial oscillation. But neither condition is any sort of guarantee, and you can get memorable winter spells without either. So in neither case can you actually make a forecast in the sense of a chart with dates and symbols.
All the other factors seem far more problematic to me. For one thing, it's a question of how they react with one another which makes it all so complicated and open to variation. And then there's the corollary that, as you say, the interactions result in those factors suddenly flipping the other way a few weeks down the line.
There ought to be some worth in studying sea-surface temperature anomalies, simply because bodies of water take a fair length of time to lose heat over the winter. But by the end of the winter even those anomalies could have flipped, as atmospheric patterns above, and ocean circulations below, do their stuff.
It doesn't help that we have so few years of data to work from. At the most about 150 separate years of global measurements, and a chunk of that, from before the satellite era, is guessed, I mean estimated. Anyone who's ever tried to identify patterns or analogies, or define what constitutes "average conditions", from past results in any field will tell you that 150 is a hopelessly small sample to work from.
Give us another 1,000 winters and then we might be able to start drawing firm conclusions about how seasons will pan out in advance.
2 miles west of Taunton, 32 m asl, where "milder air moving in from the west" becomes SNOWMAGEDDON.
Well, two or three times a decade it does, anyway.