Microbursts within landfalling tropical cyclones, and the associated environmental conditions

Microbursts within landfalling tropical cyclones, and the associated environmental conditions

Tornadoes in the outer spiral bands of tropical cyclones have been well-documented.  While hurricanes and microbursts have been widely studied separately for many years, however, there has not been any work examining potential microbursts during tropical cyclones. Microbursts are sudden, powerful descending air currents that are produced by thunderstorms. When microburst winds reach the surface, they spread out horizontally, causing property damage and a threat to aviation. Previous work has shown microbursts are characterized by dry lapse rates at the 500 MB level with moist lapse rates directly below it and a subsidence inversion near the surface. Examining landfalling tropical cyclones from 2004 – 2015, 10 possible cases were found using a combination of severe wind reports and radar.  Using both sounding and reanalysis data, the environmental conditions favorable for microburst occurrences within tropical cyclones are investigated.