Yesterday saw strong foehn winds blasting into Chamonix valley, and we saw many skiers waiting at lift stations, for cable cars that couldn’t ever open in those conditions. Several people called our Windermere office to ask for advice on how to escape the foehn. So what is it? A foehn wind is a strong mountain wind caused by damp air being forced by frontal or katabatic effects, up one side of a mountain. The air cools, moisture condenses, and it rains or snows, with the net effect that the air mass dries out. On the far side of the mountain the drier air mass drops down, and it warms up rapidly as it is compressed. The air is squeezed over the mountain tops, and accelerates downwards.
In the case of Chamonix yesterday, the wind came from the SW, so was squeezed over Mont Blanc, and the highest peaks generate the strongest foehn, to the strong warm winds to the opposite aspect was the Chamonix valley. The strong winds kept many lifts closed, and strong winds whipped the snow up in the valley. So how do you avoid he foehn? Simply move slightly East or West to get out of the firing line. Some of our groups headed to Les Contamines, and enjoyed good weather there instead. The foehn winds are easy to predict, and it’s a case of knowing the mountains well, to forecast the event, and to know how to escape it. There you go, no need to join the lemmings in a closed lift queue next time!