https://phys.org/news/2018-09-nasa-affecting-tropical-storm-paul.html

Infrared satellite data at 2:30 a.m. EDT (0630 UTC) on Sept. 10 from the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite revealed the strongest storms in Tropical Storm Paul were displaced from the center.

MODIS found coldest cloud tops had temperatures near minus 70 degrees Fahrenheit (minus 56.6 degrees Celsius) being pushed southwest of the center from northeasterly vertical wind shear. NASA research has found that cloud top temperatures that cold have the capability to generate heavy rainfall.