On the morning of September 15, 2004, NASA's Tropical Rainfall Measuring Mission (TRMM) satellite captured a 3-D look inside Hurricane Ivan, still a Category 4 storm. This unique look at Ivan shows the structure of rainfall inside the storm where red represents precipitation of 2 or more inches per hour. NASA scientists are watching the tall spires or "hot towers" inside the storm for clues about intensity fluctuations as Ivan approaches landfall. Ivan will be the third major hurricane to make landfall in the U.S. while another tropical storm, Jeanne, waits in the wings.