Ten-year climatology of summertime diurnal rainfall rate over the conterminous U.S.

Abstract

Diurnal cycles of summertime rainfall rates are examined over the conterminous United States, using radar-gauge assimilated hourly rainfall data. As in earlier studies, rainfall diurnal composites show a well-defined region of rainfall propagation over the Great Plains and an afternoon maximum area over the south and eastern portion of the United States. Using Hovmoller diagrams, zonal phase speeds of diurnal composite rainfall are estimated in three different small domains, and are evaluated with background meteorological conditions. These rainfall propagation speeds are better linked to the convective available potential energy than to the boundary-layer dryness.