AIRS image of Francisco (image) NASA/Goddard Space Flight Center Share Print E-Mail Caption On Aug. 6, 2019 at 1217 a.m. EDT (0417 UTC). the AIRS instrument aboard NASA's Aqua satellite analyzed cloud top temperatures of Tropical Storm Francisco in infrared light. AIRS found coldest cloud top temperatures (purple) of strongest thunderstorms were as cold as or colder than minus 63 degrees Fahrenheit (minus 53 degrees Celsius). Credit NASA JPL/Heidar Thrastarson Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.