A Subsynoptic-Scale Kinetic Energy Analysis of the Red River Valley Tornado Outbreak (AVE-SESAME I)

Abstract

The kinetic energy balance during the Red River Valley tornado outbreak (10?11 April 1979) is examined using mesa a-scale rawinsonde data from the first regional-scale day of AVE-SESAME 1979. Computational procedures account for non-simultaneous sonde releases, sonde drift downwind, and the substitution for some missing data. When the entire area is considered for the composite 2A h period, horizontal flux convergence due to jet intrusion is the primary kinetic energy source to the region. Cross-contour destruction of kinetic energy is the primary sink. Using the 3 h data, the energy balance is seen to change considerably throughout the experiment. Horizontal maps and limited area budgets are used to examine the energetics of a low-level jet stream and an upper-level wind maximum. Both features are maintained primarily by cross-contour kinetic energy generation that may be related to feedback mechanisms from the severe storm outbreak. Random error analyses are used to quantify confidence limits in the energy budget parameters.