Radar Characteristics of Two Afternoon Thunderstorm events during the 2022 PRECIP field campaign

Afternoon thunderstorms can result in extreme rainfall in a relatively short duration and cause severe damage from flooding and landslides. Accurately forecasting the precise initiation location, intensity, and duration of afternoon thunderstorms in Taiwan with enough lead time has been particularly challenging, partly due to the complexity of thermodynamic and kinematic processes across multi-scales, different synoptic forcings, and orographic impacts.

The Prediction of Rainfall Extremes Campaign in the Pacific (PRECIP) collected detailed radar and sounding data in Taiwan and southern Japan in conjunction with the Taiwan TAHOPE and Japan T-PARCII experiments. Two afternoon thunderstorm events with distinctive features observed during the field campaign were analyzed. On June 23rd, an afternoon thunderstorm event initiated over the mountains and became intense, with an overshooting cloud top up to 18 km in height. On June 25th, afternoon thunderstorms initiated over the northwestern plains of the island, and convection over the plains and nearby ocean became widespread. A mid-level mesocyclone persisting for around 40 minutes was observed by the S-Pol and CAA radars and dissipated when the precipitation became widespread and stratiform. Different radar signatures and initiation locations of these two afternoon thunderstorm events suggest differences in the organization and forcing mechanisms. This study focuses on identifying key similarities and differences in the radar signatures and mesoscale environments of the two thunderstorm events observed during PRECIP 2022.