The proposal examines the feasibility of using NASA and other satellite observations in regional operational flash-flood warning and response systems worldwide, and assesses any resultant flash-flood warning improvements. The observations are (a) radiance by the AIRS, AMSU-A, AMSU-B, HIRS, and MHS instruments aboard various polar orbiting satellites and GPS radio occultation refractivity for improving real-time precipitation forecasts by the Weather Research and Forecasting (WRF) model in regions of sparse upper air observations; (b) snow cover area (SCA) and LST from MODIS satellites for estimating the snow line location; and (c) surface reflectance and normalized difference vegetation index (NDVI) from MODIS (TERRA/AQUA) satellites for detecting standing water over large areas. The proposal addresses the NASA Disasters priority topic of flood prediction. Evaluation of improvements will be made by simulated operations for three regional systems: (a) the Central America Flash Flood Guidance System (in operation since 2004) for the WRF application; (c) the Black Sea and Middle East Flash Flood Guidance System (operational in 2012) for the snow line application; and (c) the Mekong River Commission Flash Flood Guidance System (in operation since 2009) for the standing water application. In collaboration with regional centers, in situ data from these regions will be used to evaluate the feasibility of using the NASA products in an operational environment to improve flash flood warnings. It is expected that ingesting the radiance and GPS data would directly improve the short term forecasts of WRF precipitation over the large domain of Central America. The snow line application is expected to allow better estimation of threat for events that cause flash floods in the mountainous terrain of the Black Sea region during and immediately after the melt season. The standing water application will benefit soil moisture estimates and warnings during the flood season in South East Asia.