3-DIMENSIONAL KINEMATIC AND MICROPHYSICAL EVOLUTION OF FLORIDA CUMULONIMBUS .2. FREQUENCY-DISTRIBUTIONS OF VERTICAL VELOCITY, REFLECTIVITY,AND DIFFERENTIAL REFLECTIVITY

High-resolution radar data collected in Florida during the Convection and Precipitation/Electrification Experiment are used to elucidate the microphysical and kinematic processes occurring during the transition of a multicellular storm from convective to stratiform stages. A stat istical technique is employed to examine the evolving properties of th e ensemble small-scale variability of radar reflectivity, vertical vel ocity, and differential reflectivity over the entire storm. Differenti al radar reflectivity data indicate that the precipitation at upper le vels was nearly glaciated early in the storm's lifetime. Dual-Doppler radar data show that throughout the storm's lifetime both updrafts and downdrafts were present at all altitudes and that most of the volume of the radar echo contained vertical velocities incapable of supportin g precipitation-size particles. Thus, the ensemble microphysical prope rties of the storm were increasingly dominated by particles falling in an environment of weak vertical velocity, and the radar reflectivity began to take on a statistically stratiform character during the early stages of the storm. This stratiform structure became more distinct a s the storm aged. Two dynamically distinct downdrafts were indicated. Lower-level downdrafts were associated with precipitation. Upper-level downdrafts were dynamically associated with the stronger upper-level updrafts and were likely primarily a consequence of the pressure gradi ent forces required to maintain mass continuity in the presence of buo yant updrafts.