Utility of Total Lightning Data in the NCAR Thunderstorm Nowcast System

The practice of nowcasting requires the forecaster to review and assimilate a variety of disparate observations and model results within the context of their knowledge of how the atmosphere works. By the nature of the nowcast problem, the time available for a human to review data and make a nowcast is always very limited. Data fusion techniques mimic much of what is normally done by the human (but without feeling the time stress). The NCAR Auto-nowcast system (ANC) provides a unique human-computer interface which allows forecasters to enter boundaries and regions of potential storm initiation. Forecaster-entered predictor fields are used along with predictors derived from NWP (RUC), Variational Doppler Radar Analysis System (VDRAS), observations, extrapolation, and feature-detection algorithms to provide detailed time and space specific forecasts of thunderstorm location and area with 0-60 minute lead times.

This paper explores the utility of total lightning data to help improve the ANC short-term forecasts. The utility of total lightning to improve forecasts of: (a) convection initiation, (b) storm severity (including C-G lightning), (c) storm top height, (d) convective organization, and (e) dissipation are explored. Individual lightning products are derived and analyzed for potential use in the ANC. Preliminary work on implementing various lightning products into the ANC at installations in the Dallas/Ft. Worth WFO offices and at the White Sands Missile Range are presented. Examples from a limited number of cases at these installations are used to demonstrate the strengths and weaknesses of this preliminary approach to the application of total lightning data.