Strong winds swept through the Alps over the weekend forcing the closure of a number of ski lifts.
SRF Meteo reported that the Joran, a wind which blows in the Jura, reached 111 km/h at Chasseral. Organisers of the Bienne carnaval were forced to close festivities between 15:00 and 17:00 on Saturday. In 2013, the same wind left one dead and around one hundred injured.
According to Meteo Swiss, the Joran is an avalanche of dense cold air. Cold air from the Atlantic accumulates in France north of the Jura. Eventually the pressure difference between this cold air and the warmer mediterranean air on the Swiss side of the Jura becomes so great than the cold heavy air rushes over the mountains and “falls” into the Swiss plateau. It is a cold, violent, “heavy” wind driven largely by gravity.
The Joran is forecast to strike again on Monday evening.
In the Alps winds were even higher over the weekend. The foehn buffeted the Gornergrat near Zermatt with gusts as high as 181 km/h and blew as fast as 143 km/h at Attelas, high up at Verbier. At Jungfraujoch in the canton of Bern, winds were as high as 141 km/h.
The foehn is different to the Joran. The foehn is a warm “light” wind, blowing in the opposite direction, which is essentially driven by pressure difference.
The foehn forced a number a ski resorts across both French- and German-speaking Switzerland to close lifts. In addition, some ferries on Lake Constance and the train between Grindelwald and Jungfraujoch were stopped.