A short-term lightning potential forecasting method

During the summer months, one of the primary roles of forecasters at White Sands Missile Range (WSMR) is to monitor convective activity and warn personnel working on the range of any associated danger, including that from lightning. The goal of this study is to describe a simple automated methodology for forecasting lightning potential at WSMR, located in southern New Mexico.

The methodology employed utilizes radar reflectivity data at two seperate altitudes above the freezing level in conjunction with convergence line detections within the atmospheric boundary layer. The radar data are processed through a filter which removes much of the weaker stratiform precipitation areas, leaving the convective regions and areas of enhanced reflectivity within stratiform regions. The boundary layer convergence line detections and their associated motions are combined with local sounding information to identify regions where further development is favored based on the boundary-relative steering flow. The final lightning potential forecast is produced by combining the radar reflectivity data and the boundary layer convergence line information using the NCAR Auto-Nowcaster, a fuzzy logic based expert system.

Example forecasts will be presented, showing discrernment between lightning producing and non-lightning producing storms. Verification results will also be presented with special emphasis being placed on amount of lead time the methodology provides compared to previously published results from similar studies.