https://phys.org/news/2018-10-nasa-walaka-powerful-hurricane.html

The GPM core observatory recently had a couple good looks at tropical storm Walaka as it was intensifying into a powerful hurricane. GPM passed directly over tropical storm Walaka when it was located south of the Hawaiian islands on September 30, 2018 at 8:38 a.m. HST (1838 UTC).

Data collected by GPM's Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments showed that Walaka was well organized and very close to hurricane intensity. GPM's Radar (DPR Ku Band) data revealed intense convective storms in a large feeder band that was wrapping around the tropical storm's northeastern side and storms wrapping around a forming eye wall. GPM's DPR found rain falling at a rate of almost 6.5 inches (165 mm) per hour in the intense storms in the feeder band northeast of Walaka's center of circulation.