Focusing Mechanisms in the Texas Flash Floods of 1978

摘要

This paper documents the meteorological conditions prior to devasting flash floods that occurred in the Hill Country of Texas on 1-2 August 1978 and in the Big Country of Texas on 3-4 August 1978; identifies the mechanisms that focused and prolonged the rains in these areas; enhances understanding of the transformation of tropical air masses as they move on shore in midlatitudes; and provides guidance for forecasting flash floods associated with intrusions of deep tropical air into midlatitudes. The role of tropical storm Amelia is analyzed. An upper air disturbance that moved from the Pacific Ocean into Mexico, and then into central Texas triggering the flash floods is discussed and several focusing mechanisms are described.