https://phys.org/news/2018-10-nasa-infrared-vision-reveals-rosa.html

The Atmospheric Infrared Sounder or AIRS instrument aboard NASA's Aqua satellite passed over Tropical Storm Rosa on Oct. 1 at 5:23 a.m. EDT (0923 UTC). and analyzed the storm in infrared light. Infrared light provides temperature data and that's important when trying to understand how strong storms can be. The higher the cloud tops, the colder and the stronger they are.

When Aqua passed over Rosa, the AIRS instrument found coldest cloud top temperatures in thunderstorms mostly northeast the center where temperatures were as cold as minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Those storms were stretching over northwestern Mexico and into Arizona. Storms with cloud top temperatures that cold have the capability to produce heavy rainfall.