Anomalies of the general circulation are shown capable of producing very dry and very wet rainy seasons over Venezuela. In 1969, a wet year, migratory synoptic systems kept passing through the area; in 1972, a dry year, a classical stationary circulation prevailed. At least part of the difference is accounted for by effect of wind shear on cumulonimbus precipitation. During large vertical shear (1972) most falling water evaporated while in 1969; with deep easterlies, cloud drops could grow to rain drop size through accretion.
1 English version of talk given at Maracay, Venezuela, as part of the 25th anniversary of the Venezuelan Air Force (FAV). This lecture was sponsored by the Meteorological Service, FAV.
2 Present Address: Institut fuer Meteorologie, Freie Universitaet Berlin.