https://phys.org/news/2018-10-nasa-lot-strength-infrared-view.html

Cloud top temperatures determine strength of the thunderstorms that make up a tropical cyclone. The colder the cloud top, the stronger the uplift in the storm that helps thunderstorm development. Basically, infrared data helps determine where the most powerful storms are within a tropical cyclone.

The Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard Aqua provided that infrared data on Oct. 2 at 9:30 a.m. EDT (1330 UTC) MODIS data showed cloud top temperatures in strongest storms around Walaka's center and in a fragmented band of thunderstorms east of the center of circulation. They were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius). NASA research indicates very cold cloud tops with the potential to generate very heavy rainfall.