Forecasting Wet Microbursts Associated with Summertime Airmass Thunderstorms over the Southeastern United States
Date of Award
Master of Science
Department of Engineering Physics
Cecilia A. Miner, PhD
Microbursts are intense downbursts from thunderstorms that affect an area less than 4 km and have a lifespan less than 10 minutes. Wet microbursts are associated with heavy precipitation and are common in the eastern and southeastern part of the country. The greatest threat from microbursts is to low flying aircraft, where the rapid fluctuations in horizontal and vertical airflow create tremendous shear zones. Microbursts have been determined to be the causal factor behind at least three major aircraft accidents resulting in numerous fatalities. Due to the short lifespan of microbursts, they often strike without warning and pose a serious challenge to operational forecasters trying to protect Air Force assets. This thesis seeks to develop a technique to forecast wet microbursts using currently operational technology, including upper air soundings and WSR-88D products. The technique developed is comprised of three distinct phases. First, recognize the potential threat for given environmental conditions. Second, predict the maximum outflow velocities from microbursts using predictive equations. Third, highlight key NEXRAD radar products that demonstrate a strong potential to serve as precursors to microburst formation. Using the technique developed, warning leadtimes on the order of 10 to 20 minutes appear to be reasonable in operational applications.
DTIC Accession Number
Mackey, James B., "Forecasting Wet Microbursts Associated with Summertime Airmass Thunderstorms over the Southeastern United States" (1998). Theses and Dissertations. 5705.