MRMS Product Distributions for NWS Warning Polygons

The Multi-Year Reanalysis for Remotely Sensed Storms (MYRORSS) is a large database of Multi-Radar, Multi-Sensor (MRMS) data for the years 1998 through 2011. The National Weather Service (NWS) has issued polygon severe storm warnings, or storm-based warnings, since 1 October 2007, although polygon data is available for some warnings for a few years prior to that date. The geospatial nature of both MRMS grids, including near-storm environment data, and the NWS storm-based warning polygons allow for data mining of the MRMS data within NWS warnings. These data can be combined with other geospatial data, such as population and land usage, to better stratify warnings beyond a simple hit/false alarm evaluation. Using a long-term radar data set like MYRORSS can also potentially explain trends in warning skill scores and year-to-year changes in warning performance. For instance, supercell thunderstorms are well understood to produce most of the significant-severe weather for the CONUS, could trends in supercell-like characteristics of MRMS grids or environments within warning’s polygon boundaries explain the year-to-year trend of warning skill scores? Discussion on application of findings to the Forecasting A Continuum of Environmental Threats (FACETs) paradigm will be included.