Some Causes of United States Drought

Abstract

Some physical causes of United States drought are outlined. Among the associated factors is subsidence,either in the upper level anticyclones or to the south of strong jets, or sometimes under prevailing northerlycomponents of upper level flow. These conditions are engendered by abnormal forms of the atmosphere'sgeneral circulation. Causative factors vary in kind and degree according to area, so that droughts over theFar West differ from those of the Great Plains or the East. Examples of each of these are shown as well astreatment of a rapidly developing drought. It should be obvious from this report that a successful numerical(dynamical) solution of the drought problem should be high on meteorologists' agendas. Abstract Some physical causes of United States drought are outlined. Among the associated factors is subsidence,either in the upper level anticyclones or to the south of strong jets, or sometimes under prevailing northerlycomponents of upper level flow. These conditions are engendered by abnormal forms of the atmosphere'sgeneral circulation. Causative factors vary in kind and degree according to area, so that droughts over theFar West differ from those of the Great Plains or the East. Examples of each of these are shown as well astreatment of a rapidly developing drought. It should be obvious from this report that a successful numerical(dynamical) solution of the drought problem should be high on meteorologists' agendas.