The hidden enemy: valley winds
The route’s longest leg between Monte Baldo and the Matterhorn will see athletes do all they can to get back into the high mountains. Here’s why.
The 2,218m peak of Monte Baldo marks the halfway point of the race but ahead lies one of the most challenging – and longest – legs in the whole course. From here, it’s 251km to the Matterhorn and the route options are numerous.
There is the shortest and most direct line over Italy’s northern lakes, Como and Maggiore – but the shortest is not always the quickest and this option will not benefit from the best flying conditions.
Then there is the route that weaves its way back into the mountains, over the Adamello and into the Valtellina valley system which looks favorable, running due west, but is prone to strong winds. Many athletes flew this route in 2011.
There are those like Gavin McClurg who believe we’ll even see athletes venturing even further north over the Bernina Alps, near Piz Corvatsch like in 2015.
If it’s raining or just not possible to fly, Paul Guschlbauer even raises the possibility that athletes could stay south and hike over flat ground. Will we see indomitable Toma Coconea take this line?
One factor above all will govern the decision. It’s complicated, says Cross Country magazine’s editor Ed Ewing, but to understand the choices that athletes face, one needs to understand what will be happening over Italy’s northern plains.
“You tend to get a big build up of heat from them,” he says. “The mountains heat up, draw air in from the south side. That air is hot and stable and it comes in as a strong afternoon wind. It’s why on all those lakes you get kite surfers. But afternoon wind kills flying. The way to avoid them is to fly high and get into the mountains. The higher up you are, the better.”
“You can start earlier and finish later in the high mountains,” he adds. “You can stitch your route together much more easily from spur to spur, rather than a route across the flatlands – the flats can be slow.”
And getting caught in those valley winds is no fun, he says. “Imagine Lake Garda as a bath tub sloshing with water. The winds draw in like water; they slosh up the side of the mountains over mountain passes, taking the easiest route. If you want to use valley winds to fly you have to have a very good understanding of what that wind is doing in that valley at that particular time of day. It gets very technical. The problem is they tend to get strong and they kill thermal development. It’s hard to escape up and out of a valley wind.
”So if we see athletes venturing 100s of kilometres to the north to get into higher terrain, we will now know why; if we hear of athletes struggling in valley winds, we’ll have a new-found respect; and if we see them taking the safer option of hiking, we’ll get that too. One thing’s for certain – this leg promises to be one of the most exciting to follow.