Radar Characteristics of Tornadic Convection in Pennsylvania Sampled by Radar at Short Range

The Warning Decision Training Division (WDTD) of the National Weather Service (NWS) coaches operational meteorologists on how to monitor tornadic convection by employing guidelines they’ve developed using decades of U.S. tornado research. Notably, the NWS has achieved moderate-to-high probability of detection (POD) scores for tornadoes in dozens of states, with POD in tornado-prone states scoring the highest. However, states such as Pennsylvania (PA) which encounter a lower—yet still significant—number of tornadoes have relatively low POD scores. To investigate this issue, dual-pol radar signatures for PA tornadoes which occurred between 2012–2022 and touched down within 50 nautical miles of a radar site were studied. This investigation illuminated a number of unique challenges for monitoring tornadic convection in the state, serving as justification for the development of state-specific standards. To determine how the national guidelines could be modified to improve POD scores for tornadoes in PA, we compared the radar signatures of our studied tornadoes to radar thresholds and storm-scale features emphasized by the WDTD.