The role of microphysical cooling processes in mesoscale convective system morphology

Mesoscale convective system (MCS) development is dependent on many factors, including environmental instability, vertical shear magnitude, orientation of the developing line to the shear, and synoptic forcing. An additional and crucial component is the development and distribution of latent cooling as the convective system evolves. Our research using microphysical and airborne radar data collected during BAMEX (McFarquhar et al. 2007, Grim et al. 2007, Smith et al. 2007) is providing insight into the importance of sublimation, melting and evaporation in different regions (and stages of evolution) of mid-latitude MCSs.

A series of simulations with the Weather Research and Forecasting (WRF) model are being carried to further our understanding of latent cooling in MCSs. Idealized simulations using environmental soundings in the vicinity of BAMEX MCSs as well as simulations over a range of vertical shear and instability are used to assess the role of cooling in MCS evolution by modifying the WRF latent cooling rates at various stages of simulated MCS lifetimes. Traditional measures (e.g. precipitation at ground, vertical velocity and simulated reflectivity structure) as well as statistical analyses (Guarente et al., this conference) will be employed to assess the convective evolution and mature structure and the role of latent cooling in mesoscale convective systems.