Evaluation of the National Convective Weather Forecast Product

The National Convective Weather Forecast (NCWF) product, designed by the National Center for Atmospheric Research (NCAR), provides current convective hazards and 1 hour extrapolation forecasts of thunderstorm hazard locations. The NCWF development is sponsored by the Federal Aviation Administration's (FAA) Aviation Weather Research (AWR) program as part of the Convective Weather Product Development Team. The target users are airline dispatch, general aviation and FAA Traffic Management Units (TMU). The product is available on the WWW via the Aviation Digital Data Service (ADDS) and on FAA-CDMnet. The diagnostic analysis combines WSR-88D national radar and echo top mosaics and cloud-to-ground lightning data. A convective hazard detection field with intensity values between 1 and 6 is derived from these data. Forecasts are determined by applying a stratiform-convective partitioner (Steiner et.al. 1985) and an elliptical filter (Wolfson et al. 1998) to the hazard detection field. These filters eliminate stratiform return and small-scale perishable features that are not a hazard to aviation or are not likely to persist for 1 hour, respectively. Extrapolations are performed based on the Thunderstorm Identification Tracking and Nowcasting (TITAN, Dixon and Wiener 1993) algorithm. Preliminary results show the product does well with long lived mature systems. However, the initiation and dissipation of these systems, as well as shorter lived air-mass storms, are not well forecasted. In this paper, a statistical approach is taken to explore the strengths and weaknesses of the product and the value of some past enhancements. Current and future upgrades will also be discussed.