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STAR Satellite Rainfall Estimates - Hydro-Estimator

The Hydro-Estimator (H-E) uses infrared (IR) data from NOAA's Geostationary Operational Environmental Satellites (GOES) to estimate rainfall rates. Estimates of rainfall from satellites can provide critical rainfall information in regions where data from gauges or radar are unavailable or unreliable, such as over oceans or sparsely populated regions.

Satellite-based estimates of rainfall have been used operationally at NOAA / NESDIS since the late 1970's, starting with the largely manual Interactive Flash Flood Analyzer (IFFA; Scofield 1987), and then progressing to the fully automated Auto-Estimator (Vicente et al. 1998). The Hydro-Estimator (H-E; Scofield and Kuligowski 2003) is the current-generation operational algorithm at NESDIS and has been used since 2002.

Estimates are produced routinely every 15 minutes for the continental United States, and are also produced for the rest of the world using available geostationary data over Europe, Africa, and western Asia (METEOSAT), and eastern Asia (MTSAT).

Details on the algorithm, which also uses data from numerical weather prediction models to correct for evaporation of raindrops, topographic influence on rainfall, and other factors, can be found at the "Technique Description" link and also in Scofield and Kuligowski (2003).


Scofield, R. A., 1987: The NESDIS operational convective precipitation estimation technique. Mon. Wea. Rev., 115, 1773-1792.

Scofield, R. A., and R. J. Kuligowski, 2003: Status and outlook of operational satellite precipitation algorithms for extreme-precipitation events. Mon. Wea. Rev., 18, 1037-1051.

Vicente, G. A., R. A. Scofield, and W. P. Menzel, 1998: The operational GOES infrared rainfall estimation technique. Bull. Amer. Meteor. Soc., 79, 1883- 1898.