Improving QPE Coverage and Estimation: The MRMS Multi-Sensor Merged QPE Phase I
Steven Martinaitis, University of Oklahoma/CIMMS and NOAA/NSSL, Norman, OK
Youcun Qi, University of Oklahoma/CIMMS and NOAA/NSSL
Carrie Langston, University of Oklahoma/CIMMS and NOAA/NSSL
Jian Zhang, NOAA/NSSL
Kenneth Howard, NOAA/NSSL

Abstract
Numerous challenges exist with estimating precipitation in areas with sparse ground-based observing platform densities and limited observational coverage due to beam blockage. This is especially true in the western United States. As part of the Multi-Radar Multi-Sensor (MRMS) version 12.0 update, the quantitative precipitation estimation (QPE) product suite will include Phase I of the Multi-Sensor Merged QPE product (hereinafter denoted as Q3MS). This Q3MS product will initially blend the MRMS local gauge corrected radar QPE (Q3GC) with the MRMS gauge plus precipitation climatology product called Mountain Mapper (Q3MM). The weight of each product in Q3MS is primarily dependent upon radar coverage through the use of an updated Radar Quality Index (RQI) product and the influence of gauge observations. The development and implementation of the Q3MS product also includes updates to the gauge quality control (QC) algorithm by utilizing satellite precipitation coverage as a proxy for assessing gauge observations in areas of poor radar coverage. This work will define the logic utilized in blending the products together to create a more accurate depiction of precipitation and statistical results showing the improved precipitation estimation. This work will also show the future of the Q3MS product (i.e., Phase II), which will include satellite QPE values and numerical weather prediction (NWP) quantitative precipitation forecasts (QPFs) in areas of poor data coverage across the contiguous United States (CONUS) and other MRMS domains, such as Alaska, Hawaii, Guam, and the Caribbean.