https://phys.org/news/2018-08-gpm-weakening-hurricane-john.html

GPM flew over John at 2:59 a.m. EDT (0659 UTC) on Aug.8. At that time John's maximum sustained wind speeds had started to decrease. GPM's Microwave Imager (GMI) and Dual-Frequency Precipitation Radar (DPR) instruments showed that most of John's precipitation was then located in the eastern half of the hurricane. A large cloud free area had developed between the center of the hurricane and an intense feeder band wrapping around the northern and western side of the hurricane. GPM's radar (DPR Ku Band) revealed that extremely heavy rainfall was still falling at a rate of over 202 mm (almost 2 inches) per hour just east of John's eye.

At NASA's Goddard Space Flight Center in Greenbelt, Md. a 3-D cross-section through hurricane John's precipitation was derived from GPM radar data (DPR Ku Band). Those data showed that the tops of powerful storms in the eastern side of John's eye wall were reaching altitudes of about 12 km (7.4 miles). Storms in the intense feeder band well north of John's eye were even higher. Probes by GPM's radar showed that storms in that area that were reaching heights above 13.5 km (8.4 miles). GPM is a joint mission between NASA and the Japan Aerospace Exploration Agency, JAXA.