Storm-Scale Ensemble Hail Analysis and Prediction using EnKF for the Supercell Thunderstorms of 20 May 2013
At sub-kilometer grid-spacing, explicit prediction of hail is possible for storm-scale ensembles using multiple-moment microphysics schemes. Storm-scale analyses and forecasts are verified against observed hail reports and radar-observed maximum estimated size of hail (MESH) obtained from the WSR-88D radar network. The EnKF produces analyses of the supercell storms which match well with observations in terms of radar reflectivity and predicted MESH. The ability of the model to correctly represent and predict hail is assessed, and factors influencing the skill of the hail forecast are investigated, including varying the length of the EnKF assimilation period and altering the dual-moment microphysical scheme used.