https://phys.org/news/2018-09-nasa-tropical-depression-olivia-strength.html

On Sept. 13, Olivia was moving rapidly toward the west-southwest, far southwest of Hawaii, however, flooding rainfall continues across parts of the main Hawaiian Islands.

At 2:20 a.m. EDT (0230 UTC) on Sept. 13, Moderate Resolution Imagine Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite analyzed Tropical Depression Olivia in infrared light. MODIS found coldest cloud top temperatures in powerful storms with cloud tops as cold as or colder than minus 70F (minus 56.6C) west of the Hawaiian Islands. NASA research has found that cloud top temperatures as cold as or colder than the 70F/56.6C threshold have the capability to generate heavy rainfall.