FORTE and GPS satellite studies have shown that satellite-based VHF lightning sensors are particularly sensitive to a ubiquitous and unique type of strong in-cloud RF lightning pulse that is sometimes accompanied by a Narrow Bipolar Event (NBE). The physical relationship between NBEs and their impulsive VHF counterparts is not clear. Presumably, the “Strong VHF Pulses” are associated with an initiating breakdown process while the NBE emissions are linked to subsequent large-scale charge flow. Strong VHF Pulses may or may not lead to NBE production (significant charge relaxation) but a NBE is always accompanied by a Strong VHF Pulse. More recent and ongoing work has focused on establishing the meteorological context of both NBEs and Strong VHF Pulses as they relate to satellite-based VHF lightning monitoring. Of particular interest is the possibility of using NBE/Strong VHF Pulse occurrence as a tool for remotely detecting severe weather.

This paper presents a case-study investigation into the relationship between NBEs, GPS-observed Strong VHF Pulses and the occurrence of severe weather. Strong VHF Pulse data from lightning-sensitive VHF receivers aboard the GPS satellite constellation will be compared to NBE data collected by the ground-based Los Alamos Sferic Array (LASA) located in Florida and the Great Plains, NEXRAD radar scans and severe weather reports in order to evaluate the relationship between these lightning types and severe weather. The GPS analysis will make use of two-satellite geometries that allows for GPS-based geolocation of lightning events in both latitude and longitude. Several case studies will be used to quantify the occurrence rates of Strong VHF Pulses with respect to NBEs and severe weather. The results will be compared to the study of Wiens and Suszcynsky (2007) to determine whether Strong VHF Pulses relate to severe weather in a manner similar to that of NBEs. The results will also be used to assess the performance of planned GPS-based VHF receivers for global lightning and severe weather monitoring.