Understanding MCS-Bore Interactions through High-Resolution Data Assimilation and Numerical Simulations

The existence of a nocturnal precipitation maximum in the Central Great Plains has been documented in a variety of climatological studies. Despite the steady progress in numerical weather prediction (NWP), forecasts of warm-season precipitation exhibit one of the lowest skill scores across different parts of the world. To further advance our understanding and predictions of nocturnal convection, it is critical to explore specific mechanisms responsible for its development and maintenance. Recent work has concluded that atmospheric bores can be an important factor in the lifetime of nocturnal MCSs. Therefore, this study explores bore-MCS interactions through ensemble-based data assimilation techniques and high-resolution numerical weather prediction (NWP) models. The main objective of this work is to understand the dynamical importance of bores for maintaining night-time convective systems and to improve forecasts of bore-MCS interactions.

Initial results show that high-resolution forecasts are able to adequately simulate the location and structure of bores. However, the numerical simulations have problems in reproducing bore-related convection, which is deemed to be critical in the MCS maintenance. Finally, this study shows the development of an object-based algorithm for the identification and tracking of density currents and bores. Example applications of this algorithm demonstrate how it could be used as an effective tool to quantify the ensemble variability in the predictions of bore-related phenomena.