Comparisons of a squall line properties between observations and bin microphysics simulations

This work compares simulations of a squall line event on May 20, 2011, during the Midlatitude Continental Convective Clouds Experiment (MC3E) using different state-of-the-art bin (spectral) microphysics schemes coupled with the Weather Forecast and Research (WRF) model in a three-dimensional quasi-idealized setup. Driven by the observed thermodynamic sounding launched about an hour before the squall line passed the sounding site, the schemes simulate well-defined squall lines that compare qualitatively well with the observed radar reflectivity. A preliminary analysis of the squall line dynamical structure, cold-pool evolution, the precipitation features and the microphysical processes in the simulations will be presented, along with brief comparisons using available radar and in-situ aircraft observations. A particular focus is on comparisons between the simulated and the detailed aircraft- observed microphysical properties near and within the melting layer of the stratiform rain region. Broadly, this work quantifies differences in organized deep convection among bin model simulations, with implications for their use as benchmarks in testing and improving bulk microphysics schemes.