Thunderstorm rain vs steady precipitation from layer type clouds, as judged by study of raindrop sizes

Abstract

Quantitatively reliable estimate by radar of precipitation intensity at a distance requires a critical prior study being made of drop size distribution in rain of various kinds and at different phases of rain fall. Observation in this regard have been made in two distinct types of radar synoptic situations-one associated predominantly with widespread continuous and relatively steady precipitation from cold stratiform clouds, and the other in which rain of a showery and more temporary and localised character occurs chiefly from very tall and highly superooled clouds as in a thunderstorm.  Some of the distinguishing features of drop size distribution and associated parameters, such as median volume diameter, total space concentration of drops, and radar reflectivity in the two situations are presented and discussed in the paper.