A Study of Thunderstorm Microphysics with Multiparameter Radar and Aircraft Observations

Abstract Excellent agreement was found between multiparameter radar signatures of hail, raindrops, and mixed-phase precipitation and in situ precipitation particle measurements made by aircraft in a northeastern Colorado hail-storm. Radar reflectivity estimates determined by remote measurement and from observed particle distributions generally agreed within 5 dB. Maximum values of differential reflectivity (ZDR) and the fractional contribution of liquid water to total reflectivity (frain) differed by less than 0.8 dB and a factor of 2, respectively. A positive ZDR column, which extended more than 2 km above the freezing level, was nearly coincident with the storm updraft. The column contained mixed-phase precipitation, but the ZDR measurement was dominated by a small number of very large raindrops (some exceeding 5 mm in diameter). Trajectories computed with a precipitation growth model suggest that many drops originated with partially or totally melted particles from a quasi-stationary feeder band within...