| Abstract: | Heavy precipitation is one of the most significant natural hazards in the United States today. Knowledge of the climatography, including the temporal characteristics, of this phenomenon is necessary in order to better plan, design for, and predict this hazard. In this study, cluster analysis is used to simplify and clarify the spatial patterns in the time of day heavy precipitation most frequently occurs. Regions with similar diurnal properties are delineated, and the substantial seasonal fluctuations in the regional patterns are traced. Of particular interest is the expansion during the cool season and contraction during the warm season of the nocturnal precipitation regime in the central United States. |
