A Statistical Assessment of Operational Forecast Products for the Detection of Regional Lightning Hazards At Current and Future Spaceports

As the United States commercial rocketry program grows in support of both federal and commercial demands, and the number of licensed and planned spaceports increases, a tool is desired to provide a regional assessment on the potential for lightning, or triggered lightning, for planning and safety assessment. There are a number of operational forecast products that are already in use to predict areas of aviation hazards associated with convective activity, such as the RUC (Rapid Update Cycle) and CIP (Current Icing Potential) operational systems. A suitable starting point is a statistical assessment of these products for the purpose of detecting areas that did experience natural lightning.For this study the United States Precision Lightning Network (USPLN) data are used to represent areas of known lightning hazards. This network is able to identify cloud-to-ground lightning (with positive or negative polarity assignment) as well as cloud-to-cloud strokes. The USPLN data have been put into 20 km grid boxes that match the CIP and RUC model resolutions. The lightning data have been partitioned into positive, negative, IC (in-cloud), and all strokes events. Hourly counts of these events in the grid boxes have been calculated. These events represent areas of known lightning hazards that are suitable for comparison to other forecast parameters that also represent environmental conditions that could support charge separation.The gridded lightning count data are statistically compared to a variety of routinely produced data sets for the determination of regional hazards to rocket activities. A comparison of the relative skill in identifying the hazard areas for various temporal periods is presented