A global climatology of extreme rainfall rates in the inner core of intense tropical cyclones

Abstract

The localized rain rate maxima (R_M) of the inner core region of intense tropical cyclones (TCs) are investigated using Version 6 of the Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis data-set from 1998 to 2010. Specifically, this study examines the probabilities of R_M exceeding 25 mm h⁻¹ (P25) in intense TCs. The 25 mm h⁻¹ R_M is the 90th percentile of all R_M observations during the study period. The descending order of P25 observed from intense TCs for the six major ocean basins is: the North Indian Ocean, the Atlantic Ocean, the Northwest Pacific Ocean, the South Pacific Ocean, the South Indian Ocean, and the East-central Pacific Ocean. The six major basins have been subdivided into 29 sub-basins to discern regional variability of R_M. P25 increases with increasing TC category in all major basins, except for the South Pacific. Sub-basins with intense TCs that produce extreme rainfall rate maxima include the Bay of Bengal, the South Philippine Sea, the East China Sea, the north coast of Australia, southeast Melanesia, and the Northwest Atlantic. Sub-basins with a higher proportion of category 5 (CAT5) observations than category 3 (CAT3) observations tend to have a greater P25 beyond 60 km from the storm center.

Keywords:

• climatology
• Ocean/atmosphere interactions
• precipitation
• remote sensing
• tropical cyclones

Acknowledgments

The authors thank NASA GES DISC for providing the TRMM 3B42 (TMPA) data and NOAA/OAR/ESRL PSD for providing the NOAA_OI_SST_V2 data. Comments and suggestions from two anonymous reviewers have helped improve the manuscript.