Hailstone size distributions and their relationship to storm thermodynamics.

Abstract

From 10 storms, 184 time-resolved hailstone samples have been collected at the ground in Alberta. For each of the samples collected, hailstone size and concentration were determined and a truncated exponential distribution was fitted to the data. From the fitted size distributions an intercept parameter No and slope parameter Lambda were obtained for each hail sample. It was found that the intercept parameters are related to the slope parameters by a power relationship of the form No= A Lambdab and that such a relationship applies to each storm individually. Furthermore, it appears that the exponent parameter of the power law b is constant from storm to storm, whereas the coefficient parameter A depends upon the storm thermodynamics. Relationships between the coefficient parameter A and cloud base temperature and maximum water mass flux are derived.-Authors