The ensemble forecasts revealed WRF-ARW sensitivity to microphysics and PBL schemes. For example, over the 7-week Experiment, the Mellor-Yamada-Janjic (MYJ) PBL and Ferrier microphysics parameterizations were associated with relatively high precipitation totals, while members configured with the Thompson microphysics or Yonsei University (YSU) PBL scheme were comparatively dry. Additionally, as the first known real-time application of a convection-allowing ensemble, the forecasts allowed us to explore different approaches for generating probabilistic severe weather guidance. In this regard, a neighborhood approach is described and shown to considerably enhance model forecast skill of severe events when combined with traditional techniques of producing ensemble probability fields.
These results have important implications for convection-allowing guidance in both deterministic and ensemble frameworks. The implications for severe convective storm forecasters will be discussed at the conference.