https://phys.org/news/2018-08-nasa-hector-large-eye-hawaii.html

At 5 a.m. EDT (0900 UTC) on Aug. 9 (11 p.m. HST on Aug. 8) NOAA's Central Pacific Hurricane Center said "Based on reflectivity data from the South Point WSR-88D radar om the Big Island, microwave images, and satellite data, it appeared that Hector went through an eyewall replacement cycle late this afternoon. Since this reorganization of the hurricane appears to be complete now, the eye of Hector has warmed and become much better defined in infrared satellite imagery during the past few hours."

On Aug. 9 at 8:25 a.m. EDT (1225 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite analyzed Hurricane Hector's cloud top temperatures in infrared light. MODIS found cloud top temperatures of strongest thunderstorms were located west of the center. In that area, cloud top temperatures were as cold as or colder than minus 70 degrees (red) Fahrenheit (minus 56.6 degrees Celsius). Cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain, so the heaviest rain was likely falling on Hector's western side.