The Man-In-The-Loop (MITL) Nowcasting Demonstration: Forecaster input into gridded nowcast products

The NCAR automated, short term (0-1 hr) thunderstorm nowcasting (Auto-nowcaster) system is currently being run at the U.S. National Weather Service (NWS) Weather Forecast Office (WFO) in Ft. Worth, Texas as part of the NWS Man-In-The-Loop (MITL) nowcasting demonstration. The MITL demonstration is a new endeavor in the NWS directed at emphasizing the increased role of the forecaster in 0-6 hr nowcasting applications, particularly in improving automated, short term nowcast products being generated for the aviation community and the public. The MITL concept was precipitated in part by results from a Federal Aviation Administration demonstration of the Auto-nowcaster documented in Roberts et al. (2003) that showed that boundaries entered into the Auto-nowcaster system by scientists during real-time operations led to significant improvement in thunderstorm initiation nowcasts. To operationally test the MITL concept, forecasters at the WFO are using the Auto-nowcaster interactive display tools to enter the locations of low-level convergence boundaries such as synoptic scale fronts, mesoscale outflows and boundaries between moist and dry boundary layer air (drylines). These boundaries are integrated into the feature detection algorithms running in the Auto-nowcaster system prior to the generation of thunderstorm nowcast products that are updated every 6 min. This task has been added to the regular list of duties ascribed to the NWS Short Term Forecaster position.

In this paper we will describe the role of the forecaster and the enhancements he/she provides to the automated nowcasting system, along with preliminary results of the performance of the forecaster-computer generated nowcast products. A qualitative evaluation of the MITL demonstration will also be discussed based on forecaster surveys and real-time log files that registered when Auto-nowcaster products were used in issuing NWS Short Term Forecasts, Area Weather Updates, Terminal Aerodome Forecasts (TAFSs) and for briefing the Spotter network. We will also discuss a parallel effort by the NWS to implement the capabilities of the Auto-nowcaster system and forecaster-interactive tools into a future build of AWIPS.