A comparison of precipitation occurrence from NCEP's StageIV QPE Product and CloudSat's Cloud Profiling Radar

The NCEP StageIV is a WSR-88D radar and gauge precipitation accumulation product that is merged and interpolated from each of the River Forecast Centers to a 4km polar stereographic grid across the CONUS. Started in late 2001, StageIV accumulations are produced at 1-, 6-, and 24-hour resolutions and are used to aid flood detection and prediction as well as inputs to hydrological downscaling models. While the WSR-88D systems are suitable for observing heavy rain events that are likely to affect flooding, distance from the nearest radar and WSR-88D sensitivity can cause them to miss precipitation especially over rough terrain and in the western CONUS. This study compares the frequency of occurrence of precipitation in StageIV against precipitation observations from collocated overpasses of CloudSat's 94GHz Cloud Profiling Radar, which provides excellent sensitivity to light and frozen precipitation.