The Use of Single-Doppler Radar for Estimating Maximum Hailstone Size

Abstract

The relationship between a storm's divergent outflow magnitude at upper levels and maximum hailstone size was investigated by analyzing single-Doppler radar data for 49 severe hailstorms. Two different techniques were developed for use with single-Doppler radar data to estimate the magnitude of divergent outflows. The developed techniques show considerable skill at estimating the maximum hailstone size produced by a thunderstorm, with the correlation coefficients between the parameters used and maximum hailstone size being as high as 0.89. The data also show that estimates of maximum hailstone size have an 80% chance of being accurate to within ±1.4 cm. The developed techniques are computationally simple and should be useful for real-time estimation of the maximum hailstone size likely to be produced by a thunderstorm.