Roger Cox: Long-range snow forecasts could transform skiing in Scotland

Roger Cox. Picture: TSPL
Roger Cox. Picture: TSPL
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Although the Scottish ski season is far from over, it’s probably fair to say that even if it snows non-stop from now until May, 2015/16 will still go down in history as a bit of a slow starter.

Following a largely snow-free December and a decidedly mixed January and early Feb, even the most die-hard optimists would have to concede that things are now looking bleak. It’s been a frustrating time for skiers and even more so for the ski centres, who have to be prepared for things to improve right the way through the season, whether that improvement materialises or not.

“Ah yes,” say the veterans, stroking their beards sagely before tucking them into their salopettes, “but the uncertainty is all part of the fun. Skiing in Scotland has always been like this, and it always will be.”

But will it?

Try to imagine a time in the not-too-distant future when it has become possible to predict with a reasonable degree of accuracy whether Scotland is in for a good snow year or a bad one. A time when, towards the end of each autumn, the folks at ski-scotland feel able to issue a bulletin that says something like: “Be advised: 2025/26 is expected to be a 4-star snow year (a 3-star year being roughly average, a 1-star year being dire and a 5-star year being spectacular).” The advantages hardly need to be spelled out: following a good forecast, skiers and boarders could postpone expensive foreign trips and plan to make the most of good conditions at home, while the ski centres could hire extra staff to deal with the anticipated crowds – perhaps using some of the money they saved the year before, when they took heed of the 1-star snow forecast and kept running costs to a bare minimum.

If that all sounds too good to be true, then allow me to introduce Michael Spencer of the University of Edinburgh’s School of GeoSciences, whose groundbreaking research, due to be published in a few weeks’ time, may pave the way for just such a forecast (although I should point out that he didn’t undertake his study specifically with skiing in mind – I’m shamelessly adapting his PhD for my own selfish ends here.)

Spencer’s work centres on something called the North Atlantic Oscillation – an irregular fluctuation in the difference in atmospheric pressure between the Icelandic Low (a semi-permanent area of low pressure which drifts around between Iceland and Southern Greenland) and the Azores High (a semi-permanent area of high pressure found near the Azores). Using four sets of Scottish snowfall records, some dating as far back as 1875, Spencer set out to determine whether these fluctuations were indicative of how much snowfall we get in Scotland and – with a few caveats, which we’ll come to in a moment – he discovered that yes, they are. Put simply, when the difference between pressure in these two areas is at its greatest (ie when the pressure in the Icelandic Low is very low, and the pressure in the Azores High is very high) we tend to experience mild conditions and warm, westerly winds; when the difference in pressure between the two areas is less marked, however, cold air is likely to blow across the European continent from the east, bringing with it more wintry conditions.

Does this mean the sci-fi snow forecasts mentioned earlier are just around the corner? Yes and no. Spencer says the Met Office have been doing seasonal forecasts of NAO for a while now, although “they’re not something that they release to the general public,” so the raw materials already exist. When it comes to predicting snow cover at ski centres, however, things get a little bit more complex. The correlation Spencer found between NAO and snow cover was strongest in the south west of Scotland, where most land is less than 750m high, and in eastern areas, which are the most exposed to easterly air flows. In inland areas where much of the land is higher (and where most of the ski centres are located) the link is not as pronounced, as low temperatures mean snow can fall even if the airflow is predominantly from the west.

“The thought is also that these central areas, perhaps because they’re further from the coast, may be more subject to local weather systems rather than windflow,” Spencer adds.

Still – let’s not sweat the little things. As far as skiing goes, a general forecast will do just fine, thanks very much. I predict November NAO forecast parties in the future, as skiers gather to find out what they’re in for in the coming winter. The brilliantly-named Edinburgh band North Atlantic Oscillation should probably brace themselves for a flurry of bookings.