A powerful Mistral raged in the Western Mediterranean yesterday. The Mistral is a powerful wind that moves south through the valley of the river Rhone and out onto the Mediterranean, caused by significantly lower air pressure at one end of the valley compared to the other. Currently, a low pressure area is located over Italy, providing the exact conditions necessary for the formation of a mistral – you can clearly see the low pressure system on the 00UTC UK Met Office ground analysis:
Peak gusts in southern France and the gulf of Lyon reached hurricane force, with one station reporting 161km/h. The Mistral has largely dissipated since yesterday.