https://phys.org/news/2018-09-nasa-hurricane-olivia-hawaii.html

At 4:45 a.m. EDT (0845 UTC) on Sept. 11, from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Terra satellite revealed strongest storms in Olivia had cloud tops with temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.

NOAA's Central Pacific Hurricane Center (CPHC) said "Hurricane Hunters from the 53rd Weather Reconnaissance Squadron found Olivia's low-level center further east than anticipated. Some conflicting data exists as to the current intensity, as the central pressure has risen, but winds in the northwest quadrant were stronger than earlier today."