Analysis of Relationships Between Lightning, Precipitation, and Runoff

More than 70% of the total annual precipitation in New Mexico can be produced by convective thunderstorms during the “monsoon season” of June through September. These thunderstorms generally are accompanied by intense lightning and characteristically produce heavy, localized rainfall often resulting in flash floods. The technology for locating cloud-to- ground lightning strikes has the potential to pinpoint these intense precipitation events as well as quantify the volume of water associated with them. This documents the spatial and temporal variability of this phenomena over large scales and can also be used for real-time flood forecasting in critical areas. This study developed algorithms between lightning and precipitation depth, used lightning data to determine rainfall depth for input to a distributed parameter hydrologic model, and tested the model to predict discharge. There was a significant correlation between rain-gauge measured precipitation and lightning within a 3 km radius of the gauge location. Precipitation prediction was greatest using regressions that included lightning strikes and relative humidity. The preliminary hydrologic modeling reinforced the need for future research to improve the estimate of spatial and temporal characteristics of lightning related precipitation events. Lightning location technology, combined with a Geographic Information System (GIS) approach, has potential value for defining the spatial and temporal resolution of intense, summer precipitation patterns.