NASA's TRMM spacecraft observed this view of Hurricane Dean on August 19, 2007. At this time the storm was classified as a dangerous category four with sustained winds of 125 knots (138 mph). The cloud cover is taken by TRMM's Visible and Infrared Scanner(VIRS) and the GOES spacecraft. The rain structure is taken by TRMM's Tropical Microwave Imager (TMI) and TRMM's Precitation Radar(PR) instruments. TRMM looks underneath of the storm's clouds to reveal the underlying rain structure. Blue represents areas with at least 0.25 inches of rain per hour. Green shows at least 0.5 inches of rain per hour. Yellow is at least 1.0 inches of rain and red is at least 2.0 inches of rain per hour.