A Kinetic Energy Analysis of a microburst-Producing Thunderstorm Based on JAWS Dual-Doppler Data

Abstract

Dual-Doppler data collected from 1646 to 1648 MDT 14 July 1982 in Colorado are used to study the kinetic energy budget of a microburst-producing thunderstorm during its mature stage. Values of each term in the kinetic energy budget equation are assessed from the Doppler derived winds and retrieved thermodynamic fields using a fourth-order finite differencing with 0.5 km grid spacing. Results indicate that vertical totals of the horizontal generation and horizontal flux divergence terms act as a source of kinetic energy, while a vertical total of dissipation is a sink. The horizontal flux divergence term is nearly in balance with the vertical flux divergence term. Similarly, the vertical generation and total buoyancy production terms have the same order of magnitude but opposite signs at most levels. In the lower layer, where the microburst dominates, the kinetic energy is transported downward. In the middle and upper layers, the kinetic energy is transported upward due to the storm's strong convective updrafts.