Disdrometer measurements during an intense rainfall event in central Illinois: implications for differential reflectivity radar observations.

Empirical relationships for estimating rainfall rate, liquid water content and median volume diameter from radar measurements of reflectivity factor and differential reflectivity are derived from a disdrometer record of a highly variable, heavy rainfall event in central Illinois. Comparisons with relationships representing exponential and gamma model drop-size distributions are made. Simulations, employing these and Z-R relationships for rainfall estimation, are performed. Statistical measures are tabulated for comparing results. These show an excellent agreement between the disdrometer- and radar-derived rainfall parameters when the latter are obtained from the empirical relationships.-Authors