Improving Coverage and Accuracy of Precipitation Estimates for NOAA and NWS through a Multi-Sensor Precipitation Scheme

Accurate high resolution QPE products are critical to operational decision making, flood prediction, and climatological assessments conducted by the National Oceanic and Atmospheric Administration (NOAA), the National Weather Service (NWS), and the National Water Center (NWC). Two primary sources for estimating precipitation are from radar and gauge networks; however, there are considerable coverage gaps with both sensor suites, particularly in the intermountain West, Hawaii, and Alaska. A new precipitation product is being developed in the Multi-Radar Multi-Sensor (MRMS) system that blends together locally gauge-corrected radar quantitative precipitation estimates (QPE), the Mountain Mapper QPE product that maps hourly gauge observations onto background precipitation climatologies, satellite-derived QPE, and high resolution model quantitative precipitation forecasts (QPFs).

The radar-based QPE is the foundational precipitation source, and its influence within the new multi-sensor QPE product is defined by an updated MRMS Radar Quality Index product. Gaps in radar coverage are then filled using a combination of the other precipitation sources based on their strengths. This multi-sensor QPE product for the MRMS system is initially developed for the contiguous United States and will eventually be implemented and tailored to other domains, such as Hawaii, Alaska, and the Caribbean. The final product will allow for improved hydrologic forcing for the National Water Model as well as provide a more accurate precipitation field to be used by the NWS and other entities for flood prediction and water resource management. This presentation will discuss the design of the multi-sensor QPE product and the case study analysis of events over the western United States where observational coverage is sparse. These studies include comparisons of the variety of MRMS and other precipitation sources against independent CoCoRaHS gauge observations over 24-hour accumulation periods.