Abstract

This study investigates the performance of the NOAA/NESDIS operational rainfall estimation algorithm, called the Hydro-Estimator (HE) with and without its orographic correction method, in its depiction of the timing, intensity, and duration of convective rainfall in general and of the topographyr... Show moreThis study investigates the performance of the NOAA/NESDIS operational rainfall estimation algorithm, called the Hydro-Estimator (HE) with and without its orographic correction method, in its depiction of the timing, intensity, and duration of convective rainfall in general and of the topographyrainfall relationship in particular. With a few exceptions, validation of satellite rainfall estimates in complex terrain has been lacking to date due to the paucity of pre-existing dense observation networks in mountainous areas. An event rainfall observation network in northwest Mexico, established as part of the North American Monsoon Experiment (NAME), provides gauge-based precipitation measurements with sufficient temporal and spatial sampling characteristics to examine the climatological structure of diurnal convective activity over northwest Mexico. In this study, rainfall estimates from the HE algorithm were evaluated against point observations collected from 49 rain gauges from August through the end of September in 2002 and from 79 gauges from August through September in 2003. While the HE with orographic correction in some extent captures the spatial distribution and timing of diurnal convective events, elevation-dependent biases exist, which are characterized by an underestimate in the occurrence of light precipitation at high elevations and an overestimate in the occurrence of precipitation at low elevations. The potential of the HE in providing high spatial and temporal resolution data is tested in a hydrological application over the NAM region. The findings suggest that continued improvement to the HE orographic correction scheme is warranted in order to advance quantitative precipitation estimation in complex terrain regions and for use in hydrologic applications. Show less