NASA's TRMM spacecraft observed this view of Tropical Storm Hanna on September 1, 2008 at 1418 UTC (10:18 EDT). At this time the storm was a tropical storm with sustained winds of 50 knots (57.5 mph) and a pressure reading of 994 millibars. Three hours later, The National Hurricane Center upgraded this storm to a category 1 hurricane with sustained winds of 70 knots and a pressure reading of 984 millibars. TRMM documented one reason for this rapid intensification - strong thunderstorms with heights of over 17 kilometers (10.5 miles) in the eastern eyewall of this tropical storm. 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. The rain structure is colored by the height of the clouds. Note: TRMM's Precipitation Radar (PR) instrument observed this 17 kilometer tower in the eatern eyewall as Tropical Storm Hanna was intensifying to a category 1 hurricane on September 1, 2008. Data Collected: 9/1/08. Animator: Lori Perkins (NASA/GSFC). Scientist: Scott Braun (NASA/GSFC). Platforms/Sensors/Data Sets: GOES, TRMM/PR, TRMM/TMI, TRMM/VIRS.