Date Last Updated
August 8th, 2025
Document Description

The Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission (IMERG) combines precipitation retrievals from all available low-orbit passive microwave (PMW) data, together with geosynchronous infrared (GEO-IR) providing baseline retrievals to compute merged global precipitation every half hour. The IMERG Early Run includes forward propagation of PMW data, while the Late Run also uses backward propagation. IMERG includes the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager/Sounder (SSMIS) constellation operated by the U.S.

File Downloads
IMERG Hurricane Harvey (2024) 30-minute summary
NASA's Worldview website now allows you to explore global estimates of rainfall and snowfall from 1998 to the present at 30-minute intervals. Researchers and application developers have been using this dataset since 2014 (Portier 2024; Portier et al. 2023), but now it is also available as images in Worldview.
3D view of the Texas storms from the GPM satellite
Over the fourth of July weekend, the Texas Hill Country was devastated by a powerful flash flood event. River levels rose rapidly, on the order of 20 feet or more in 1 to 2 hours or less, all along the upper part of the Guadalupe River. The main flood event started overnight and continued throughout the morning of July 4, resulting in widespread destruction, hundreds of water rescues, many deaths, and numerous people still reported as missing. The Hill Country can be susceptible to flash floods as water tends to run off rather than being absorbed by the soil and plants. The culprit for this