https://phys.org/news/2018-08-nasa-infrared-tropical-storm-ileana.html

On Aug. 6 at 4:40 a.m. EDT (0840 UTC) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Terra satellite analyzed Tropical Storm Ileana's cloud top temperatures in infrared light. MODIS found cloud top temperatures of strongest thunderstorms were as cold as or colder than minus 80 degrees Fahrenheit (minus 62.2 Celsius) around the center. Cloud top temperatures that cold indicate strong storms that have the capability to create heavy rain.

The National Hurricane Center cited that infrared temperature data in their 5 a.m. EDT discussion, "A strong burst of deep convection consisting of some cloud top temperatures of minus 85 to minus 90 degrees Celsius near the center has developed during the past several hours."