Rain Microphysical Characteristics of Rapidly and Slowly Intensifying Tropical Cyclones over North Indian Ocean

This study investigates the rain microphysics of tropical cyclones (TCs) that underwent rapid (RI) and slow intensification (SI). TCs that formed in the North Indian Ocean (NIO) are considered, particularly over the Arabian Sea (AS) and Bay of Bengal (BOB) regions for years 2014-2023. Among the 114 TCs recorded in NIO, 42 underwent intensification (RI-22; SI-20). The probability density functions (PDFs) of rain microphysics parameters vary with the intensification mode (RI and SI) and the type of rain (total, stratiform, and convective). The storm height is slightly taller in RI than SI TCs, most notably in convective systems, which underscores the structural difference between the two intensification categories. The contour frequency by altitude diagrams, as well as the vertical mean profiles, reveal that for all rain types, RI TCs have higher rain rates (R), stronger reflectivity (𝑍), larger drop size diameters (𝐷𝑚), and lower drop concentrations (𝑁𝑤) as compared to SI TCs. Results from this study may be used to delineate an impending RI from SI.