Hurricane season in the eastern Pacific started off with a whimper late last month as Alma, a Category 2 hurricane, slowly made its way up the coast of Baja California, packing sustained winds of 110 miles per hour and gusts of 135 miles per hour. The above image of the hurricane was acquired on May 29, 2002, and displays the rainfall rates occurring within the storm. Click the image above to see an animated data visualization (3.8 MB) of the interior of Hurricane Alma. The images of the clouds seen at the beginning of the movie were retrieved from the National Oceanic and Atmospheric Association?s (NOAA?s) Geostationary Orbiting Environmental Satellite (GOES) network. As the movie continues, the clouds are peeled away to reveal an image of rainfall levels in the hurricane. The rainfall data were obtained by the Precipitation Radar aboard NASA?s trmm.gsfc.nasa.gov/ Tropical Rainfall Measuring Mission (TRMM) satellite. The Precipitation Radar bounces radio waves off of clouds to retrieve a reading of the number of large, rain-sized droplets within the clouds. Using these data, scientists can tell how much precipitation is occurring within and beneath a hurricane. In the movie, yellow denotes areas where 0.5 inches of rain is falling per hour, green denotes 1 inch per hour, and red denotes over 2 inches per hour. (Please note that visibleearth.nasa.gov/cgi-bin/viewrecord?13511 high resolution still images of Hurricane Alma are available in the NASA Visible Earth in TIFF format.)
