It is an increasingly frequent event. Saharan sand on your car in the morning and covering the ski slopes. According to Meteo France the dust cloud formed in the north of Algeria and is rarely seen in such proportions. According to the forecasters "The cloud formed at the front of an unstable weather system associated with strong winds on the ground. It was then carried to our regions by the fast and high southerly airstream".
Col du Lauteret, Hautes-Alpes this morning
The dust adds to other small particles and degrades the air quality. The air quality in Grenoble was classed as "very bad" today with a large quantity of PM10 particles. Not good for people with breathing difficulties. Further south in Nice the PM2.5 level is 11 times the level of the WHO recommendations. There is also a question of how radioactive the dust is. In the 1960s France carried out nuclear tests in the Algerian desert.
l'Alpe d'Huez
As far as skiing is concerned. The strong southerly foehn winds have closes lifts and even ski resorts as falling trees have blocked access roads. The sand itself lowers the albedo of the snow causing it to melt faster and can help create unstable layers in the snowpack when there is fresh snow. These sand events generally mean a shorter spring season and early thaw as the snow absorbs more energy.
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