During Spring 2013, the Mesoscale Predictability Experiment (MPEX) sought to improve short-term (here 6-15 h) forecasts of convective weather episodes over the Great Plains. MPEX approached this challenge by increasing observation density with mesoscale spaced (~150 km) dropsonde observations in the vicinity of disturbances upstream of uncertain convective weather events. Potentially uncertain ICs were identified in part by formal ensemble sensitivity analysis (ESA) from longer-range forecasts. Fifteen dropsonde missions were conducted, which included events with a wide range of convective organization.
In retrospective case studies, the impact of the additional dropsonde observations is determined through a set of data denial experiments with the WRF/DART ensemble data assimilation system and subsequent ensemble forecasts. Verification of ensemble forecasts is made against conventional and research observations. Further, we assess the relative utility of ESA to identify a priori targeted observation locations for convection forecasts. At the conference, a brief overview of MPEX will be presented along with a discussion of results.