French Riviera the weather between various locations. Strong winds such as the Mistral, a cold dry wind from the northwest or from the east, are another characteristic, particularly in the winter. Nice and the Alpes-Maritimes département are sheltered by the Alps. The winds are usually gentle, from the sea to the land, though sometimes the mistral blows strongly from the northwest, or, turned by the mountains, from the east. In 1956 a mistral from the northwest reached at Nice Airport. Sometimes, in summer, the sirocco brings high temperatures and reddish desert sand from the Sahara. (See Winds of Provence.) Rain can be
Mistral (wind) reputation for making the sky especially clear. There is also, however, the mistral noir, which brings clouds and rain. The mistral noir occurs when the Azores High is extended and draws in unusually moist air from the northwest. The long and enclosed shape of the Rhône Valley, and the Venturi effect of funnelling the air through a narrowing space, is frequently cited as the reason for the speed and force of the mistral, but the reasons are apparently more complex. The mistral reaches its maximum speed not at the narrowest part of the Rhône Valley, south of Valence, but much