Study: Tropical storms produce most rain

WASHINGTON, Dec. 11 (UPI) -- A NASA-funded study suggested that tropical storms over the Southeastern United States do more to alleviate drought than do hurricanes.

The new study, using National Aeronautics and Space Administration satellite data, showed smaller tropical storms deliver greater cumulative rainfall to an area than do hurricanes during the course of a season.

The study focused on a decade of first-ever daily rainfall measurements by a NASA satellite carrying a weather radar in space. The study's authors said they believe the same insights can be applied to other regions where daily satellite rainfall and storm tracking data are available.

"As much of the Southeast experiences record drought, our findings indicate that weak tropical systems could significantly contribute to rainfall totals that can bring relief to the region," said University of Georgia Associate Professor Marshall Shepherd, lead author of the study. "These types of storms are significant rain producers."

The researchers found although major hurricanes can produce the heaviest rainfall on any given day, smaller tropical storms and depressions collectively produced the most rainfall during the entire rainfall season.

The full report is available at http://www.nasa.gov/mission_pages/hurricanes/archives/2007/smallstorm_largerain_prt.htm.