Tropical Rainfall Potential (TRaP) has been performed operationally in the U.S. National Oceanic and Atmospheric Administration 's (NOAA) National Environmental Satellite, Data and Information Service (NESDIS) since the mid-1980s. Today the process incorporates a satellite based observation of instantaneous microwave rain rates from NOAA's Advanced Microwave Sounding Unit (AMSU-B), National Aeronautics and Space Administration's (NASA) Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), Defense Meteorological Satellite Program 's (DMSP) Special Sensor Microwave Imager (SSM/I), European Space Agency's(ESA) MetOp and NASA's Advanced Microwave Scanning Radiometer(AMSR-E). These products are then projected over time using the official track forecasts of the Joint Typhoon Warning Center and the Regional Specialized Meteorological Centers (RSMC) in Miami, Honolulu, Tokyo, La Reunion, Perth, Darwin, Brisbane, Nadi, New Delhi and Wellington to determine a rain rate over any point. Rain amounts are then integrated for every point in the image over a 24 hour period.

Validation of the TRaPs for U.S. landfalling hurricanes during the 2004 through 2007 Atlantic hurricane seasons will be shown. TRaP amounts will be compared with Stage IV observed amounts using a validation package that objectively computes a number of statistical parameters between the two rain fields. The next generation TRaP, an ensemble approach dubbed eTrap will also be described.