Comparison of model analyses and observations of impacts by deep convection on the surrounding environment

Christopher Kerr* and David Stensrud, Xuguang Wang
University of Oklahoma, Penn State University, University of Oklahoma

Convective environments nearby deep convective storms were sampled during the Mesoscale Predictability Experiment (MPEX). Few previous studies have focused on the environment surrounding convective storms to explore how convection influences this environment. In particular, upsondes released in near-storm environments provide unique opportunities to evaluate convective-scale numerical weather prediction model capability and accuracy. A four-day sequence of convective events in May 2013 will be the focus of this study. 28-May features a thunderstorm cluster in southern Kansas. An MCS develops in the Texas Panhandle and moves into western Oklahoma on 29-May. 30- and 31-May include a nontornadic and tornadic supercell, respectively. MPEX soundings were released in a variety of locations near the target convection to sample the environments. The events are modeled using a 36-member nested ensemble of the Weather Research and Forecasting Model (WRF). Observations are assimilated using an ensemble adjustment Kalman filter (EAKF) with the Data Assimilation Research Testbed (DART). Results show reasonable ensemble spread of wind shear surrounding the target convection, especially in the convection's wake. There is an apparent underprediction of wind shear in areas where convection has enhanced the environmental wind shear, mainly in the wake of convection and inflow region of supercells. Model analysis biases of wind and thermodynamic profiles are evaluated to assess the model's accuracy.

*Preference: Oral