Factors Affecting the Size Distribution of Raindrops and Snowflakes

Many observations have been made of size distributions of raindrops, aggregated snowflakes, graupel and hailstones under various meteorological conditions. The size distributions have been studied in conjunction with upper air soundings which were used to determine the original shape or snow crystal form of the hydrometeors. It was concluded that the size distribution of raindrops is dependent on that of the precursor snowflakes which is controlled by the shape of the snowflakes and the upper air conditions.