Numerical Simulation of an Intense Squall Line during 10–11 June 1985 PRE-STORM. Part II: Rear Inflow, Surface Pressure Perturbations and Stratiform Precipitation

Abstract

Abstract An intense rear-inflow jet, surface pressure perturbations, and stratiform precipitation associated with a squall line during 10–11 June 1985 are examined using a three-dimensional mesoscale nested-grid model. It is found that the large-scale baroclinity provides favorable and deep rear-to-front flow within the upper half of the troposphere and the mesoscale response to convective forcing helps enhance the trailing extensive rear inflow. However, latent cooling and water loading are directly responsible for the generation of the descending portion of the rear inflow. The role of the rear inflow is generally to produce convergence ahead and divergence behind the system, and thus assist the rapid acceleration of the leading convection when the prestorm environment is convectively favorable and the rapid dissipation of the convection when encountering unfavorable conditions. In this case study, the rear-inflow jet appears to have caused the splitting of the surface wake low as well as the organized ...