This infrared image of Tropical Storm Harvey occurred at the same hour of landfall in southwestern Louisiana. The AIRS instrument aboard NASA's Aqua satellite captured this image on Aug. 30 at 4:17 a.m. EDT (0817 UTC), and purple indicates the strongest storms. Credit: NASA JPL, Ed Olsen

Infrared data provides temperature information and the highest, coldest cloud tops in tropical cyclones indicate where the strongest storms are located.

NASA's AIRS instrument provides that critical temperature information and captured an image of Harvey within the hour of its landfall in southwestern Louisiana.

Harvey made landfall just west of Cameron, Louisiana at 4 a.m. CDT, Aug. 30.

Radar images of Houston, Texas before and after Hurricane Harvey made landfall were taken by The German Aerospace Center's TerraSAR-X satellite. Flooded areas appear in light blue. Waterways appear in darker blue. Credit: German Aerospace Center (DLR)