The Dynamics of Circulations within the Trailing Stratiform Regions of Squall Lines. Part I: The 10–11 June PRE-STORM System

Abstract

Abstract A dynamic version of the two-dimensional kinematic cloud model of Rutledge and Houze has been developed to investigate the effects of microphysics on circulations within the stratiform regions of mesoscale convective systems. The design of the model allows for specified inputs of hydrometeors, water vapor, and heat from the convective line. The stratiform region of the 10–11 June 1985 PRE-STORM squall line is simulated, with initialization based upon appropriate soundings, heat budgets, and ID cumulonimbus model results. The model accurately simulates the evolution of the stratiform rain area. Significant ascent occurs in the stratiform region where in situ condensate production contributes increasingly to the surface rainfall, reaching 65% of the total in the mature stage and averaging 44% over the entire simulation. The ratio of condensate produced within the mesoscale updraft to that advected from the convective line generally agrees with water budgets from other studies. Simulated horizontal ...