Simulated NWS Tornado Warning Decisions Using Rapid-scan Radar Data

Analysis of a tropical tornadic supercell by NWS forecasters during the 2010 Phased Array Radar Innovative Sensing Experiment (PARISE) suggested that the use of rapid-scan radar data can result in longer warning lead times compared to use of traditional 4.5-min data. To increase the sample size and learn more about forecasters' conceptual models and warning decisions, twelve NWS forecasters participated in the 2012 PARISE, which ran for six weeks during June – August 2012. Two forecasters participated each week. The experiment's goal was to test whether rapid, adaptive sampling with the phased array radar at the National Weather Radar Testbed increases NWS forecasters' ability to effectively cope with tough tornado warning cases.

During the experiment each forecaster worked four cases ranging from 18–52 min in length. Their activity was videotaped. For each case, the forecasters' goal was to decide whether a tornado warning was warranted. Before each case the forecasters received a pre-recorded weather briefing that provided situational awareness of the environment. The forecasters then worked the case in displaced real time using AWIPS II. RecordMyDesktop software recorded forecaster interaction with the radar data. After each case the forecasters reviewed the video and worked with researchers to build a timeline of their actions, what they saw and interpreted in the data, and their decision process. They also completed confidence and mental workload rankings. Finally, forecasters drew pictures and described the conceptual model they developed during each case. Findings from the experiment will be presented.