Overview of the Tropical Cyclone Rapid Intensification (TCRI) Program

The Tropical Cyclone Rapid Intensification (TCRI) Experiment, sponsored by the Office of Naval Research (ONR), is a multi-year program focused on developing new understanding of rapid intensification (RI) of tropical cyclones through insight gained from new observations and results from high-resolution numerical models. Although the ingredients for and basic mechanisms of TC intensification are well-understood, the processes governing the transition from genesis to rapid intensification remain largely unknown. Additionally, TC prediction models have great difficulty accurately predicting the onset and subsequent rate of intensification for such post-genesis, weak TCs.

Motivated by these deficiencies in our understanding and prediction of RI, the ONR TCRI observing program has been closely coordinated with the NOAA Hurricane Research Division (HRD) Advancing the Prediction of Hurricanes Experiment (APHEX) utilizing two NOAA P-3 Orion aircraft and the NOAA G-IV jet. The instruments onboard these aircraft have included flight-level measurements, tail Doppler radar (TDR), stepped frequency microwave radiometer (SFMR), GPS dropwindsondes, cloud microphysics probes, the Imaging Wind and Rain Airborne Profiler (IWRAP), the Wide Swath Radar Altimeter (WSRA), and the Compact rotational Raman Lidar (CRL). A total of 15 storms have been intensively observed during the 2020-2023 seasons including noteworthy storms Hurricanes Delta (2020), Ida (2021), Ian (2022), and Idalia (2023) in which RI conditions were observed in multiple flights. In this presentation, we will provide highlights of the TCRI observing campaign, as well as new insights and questions motived by these observations and companion modeling studies.