This is the name given to a wind which blows in the Rhone Valley in France. The wind is caused by an exchange of air between the cold hinterland of France's Central Plateau and the warm Gulf of the Lion in the Mediterranean Sea.
High mountain ranges near flat country produce unpleasant winds, especially where the mountains descend to a warm sea. Atmospheric pressure is high above the cold mountains, but low above the sea. Air, therefore, flows towards the sea and is not warmed because it has not crossed enough land.
The north-westerly mistral, funneling down the construction of the Rhone Valley, blows at a speed of 30 to 60 mph on at least 50 days each year. It bursts out on to the Mediterranean coast, filling holidaymakers' caravans with sand and capsizing yachts caught unaware at sea.