Tropical Cyclone Intensity Changes Associated with Inner Core Lightning

Recent studies have found contradictory results on the intensity change associated with lightning outbreaks in the inner core of tropical cyclones (TCs).  These studies, which focus on the flash density of lightning in the entire inner core region (generally 0–100 km), have found an association with weakening in some studies and intensification in others, suggesting that flash density alone cannot provide a definitive sign of future intensity change.

This study will utilize data in eastern North Pacific and North Atlantic TCs from the World Wide Lightning Location Network (WWLLN) between 2005 and 2014 to better understand the discrepancies found in previous studies, and further evaluate the utility of lightning data in TC intensity forecasting.

A climatology of deep convective bursts (i.e., concentrated regions of lightning flashes) in the TC inner core region (0–150 km) is created. These bursts are analyzed for patterns that may support or hinder intensification, such as: 1) the intensity change prior to the burst, 2) the azimuthal location of the burst relative to the deep-layer vertical wind shear vector, and 3) the radial location of the burst relative to the radius of maximum wind.