The spatial and temporal distribution of lightning in hurricanes before and after landfall has been examined. The study makes use of cloud-to-ground lightning locations from the National Lightning Detection Network. During hurricane stage a common radial distribution in ground flash density was evident: a weak maximum in the eye wall region, a clear minimum 80-100 km outside the eye wall, and a strong maximum in the vicinity of outer rain bands (210 to 290 km radius). The results support the division of precipitation in the hurricane into three distinct regimes. The eyewall is a unique phenomenon, but shares some attributes with deep, weakly electrified oceanic monsoonal convection. The region outside the eyewall and under the central dense overcast has characteristics of the trailing stratiform region of mesoscale convective systems, including a relatively high fraction of positive polarity flashes. The outer bands, with mean maximum flash density at the 250 km radius, contain the vast majority of ground flashes in the storms.
Subsequent work has focused on two areas: lightning after landfall, and lightning in the hurricane eye wall. This work will be presented at the conference. The focus will be on (i) Changes in the radial distribution of flash density in the 12 hours after landfall; (ii) Azimuthal distribution of lightning and its relationship to vertical wind shear and direction of storm motion; and (iii) Unusual lightning in the eye wall before and after landfall. The emphasis of the work is to use knowledge of lightning to understand the convective structure of the hurricane and its evolution during intensification and after landfall