Simulations of the May 20 MC3E Squall Line Case: Impacts of Evolving Ice Habits on the Transition Region and Stratiform Precipitation

 
Poster PDF

Authors

Edwin Lee Dunnavan — Cooperative Institute for Mesoscale Meteorological Studies
Anders Jensen — Pennsylvania State University
Jerry Y. Harrington — Pennsylvania State University

Category

Microphysics (cloud and/or aerosol)

Description

Microphysical models often have difficulties in reproducing the main precipitation structure of midlatitude squall lines. While all models are capable of producing the leading line of strong precipitation, most models have difficulties reproducing both the transition region of weak precipitation that follows the leading line and the broad region of steady stratiform precipitation that follows the transition region. In contrast, simulations conducted with a model that predicts the evolution of particle shapes during vapor growth and riming (Harrington et al., 2013 and Jensen and Harrington, 2015) can reproduce this observed precipitation structure and for a variety of microphysical scenarios. Prior observational and modeling studies have put forth a variety of microphysical explanations for the transition and stratiform regions, and our simulations suggest that all of the prior explanations are equally viable. This result also provides an explanation for the robust nature of the transition region of squall lines. Results from the model integration are currently being compared with in-­‐situ data and forward modeling radar analysis from the case, and results will be presented at the meeting.