Abstract
It is shown by the observational data and the numerical experiments, that the local strong wind appears under the lee of a mountain when air crosses over the mountain, being cooled from the earth's surface. It is also shown by the numerical experiment that strong wind appears under the lee when cold air passes over the mountain, but generally it is not so in the unstable layer, and a crowd of convection cells is produced in the unstable layer originated with heating from the ground surface in the daytime. The character of such crowd of convection cells as the gravity waves is discussed.
