Validating Hail Production and Accumulation from the New Three-Moment Thompson Microphysical Scheme

Deep-hail events, which can feature enough accumulation to require removal by snow plows, occur routinely in Colorado and the High Plains. These extreme weather events damage plants and infrastructure, and snarl traffic causing significant inconvenience to business and interstate commerce. Though radar-based, observational analyses of hail metrics exist, but do not allow advance prediction of hail events. This work compares a new 3-moment microphysics scheme by Greg Thompson (NCAR) to radar-based metrics to assess the potential of such a scheme in providing predictive capability for hail size and accumulation. We find that deep hail potential, but not placement may be diagnosed with this model. However, the microphysical scheme does produce reasonable hail accumulation depths, though graupel/hail accumulation in cold sector regimes may be overdone.