Kinematic and precipitation structure of the 10-11 June 1985 squall line

Abstract

First, a difference in the horizontal scale was found between the mesoscale updraft, which at upper levels was on the scale of the trailing stratiform cloud, and the strong mesoscale downdraft, which at mid-to-lower levels was on the scale of the trailing stratiform precipitation. Second, the region of heaviest stratiform precipitation (the secondary band) was found to be immediately downwind of the most intense portions of the convective line, and the width of the trailing stratiform precipitation region was controlled by a combination of the wind velocity and microphysical fall-speed scales. Third, the radar reflectivity minimum observed at mid-to-lower levels in the region just behind the convective line was found to coincide with deep subsidence from mid-to-upper levels, which may have reduced the mass of the hydrometeors through sublimation and evaporation. -from Authors