A Tale of Two Mesovortices: Analyses of a Simulated Severe MCS Observed by PECAN on 5-6 July 2015
Understanding and forecasting nocturnal thunderstorms and their hazards remain elusive goals. To this end, an expansive array of fixed and mobile observing systems were deployed in the summer of 2015 for the Plains Elevated Convection At Night (PECAN) field experiment to intercept and observe nighttime atmospheric phenomena. During the night of 5 July 2015, an array of eight mobile radars and numerous ground-based surface and upper-air profiling systems sampled a severe mesoscale convective system (MCS) as it moved through southeastern South Dakota. The MCS was responsible for several severe wind reports, including one over 80 mph, and produced a high-end EF-0 tornado near Dolton, SD.
In this study, observations of these phenomena from mobile mesonets, radars, and aircraft are assimilated into the NSSL Experimental Warn-on-Forecast (WoF) System for ensembles (NEWS-e) to generate high-resolution analyses and short-term ensemble forecasts of the event. Tests are conducted to determine the grid spacing required to simulate the mesovortices. Progress on determining the meteorological processes influencing the development of significant low-level rotation will be presented.