Comparison of Horizontal Cloud-To-Ground Lightning Flash Distance Using Weather Surveillance Radar And The Distance Between Successive Flashes Method

摘要

On April 29th, 1996 an airman servicing a C-130 aircraft on Huriburt AFB Florida was struck and killed by a lightning flash that traveled an estimated 7 to 10 miles from storms south of the airfield. Ten other workers were injured in the incident. The fatal flash occurred just 8 minutes after the base weather station allowed a lightning advisory to expire. The incident brought to question the adequacy of lightning advisory criteria. Very little research has been done on the horizontal distance that cloud-to-ground lightning flashes occurs from the center of a thunderstorm. This thesis used the WSR-88D method, which used the WSR-88D Algorithm Testing And Display System (WATADS) to calculate the distance from a lightning flash to a thunderstorm centroid. The WSR-88D method was compare with a lightning spatial and temporal clustering method known as the Distance Between Successive Flashes (DBSF) method. This method can use enormous amounts of lightning data, and is well suited to accomplish a climatology of horizontal flash distance from a lightning centroid. For the combined April and July 1996 data used in this thesis, the average percentage of lightning flashes that occurred beyond the 5 nautical niile lightning safety radius outlined in AFOSH 91-100 for both the WSR-88D method and the DBSF method was 30.86%. This result questions the adequacy of the 5 nautical mile lightning safety distance criterion currently being used at most United States Air Force Bases for protection both life and property.