Convective updraft and downdraft characteristics of continental mesoscale convective systems in the model gray zone

This zone typically covers Delta x from a few kilometers to several hundred meters, wherein the realistic representation of convective cloud processes can be challenging. This study characterizes the convective draft behaviors at multiple Delta x across the gray zone and determines the appropriate Delta x that can reliably capture these salient convective properties.

We perform an ensemble of idealized simulations of mesoscale convective systems (MCS) using the Weather Research and Forecasting model at various Delta x from 4 km to 250 m over the central U.S. An evaluation of key MCS kinematic properties is constrained using unique, long-term vertical velocity estimates obtained by radar wind profilers deployed by the Department of Energy Atmospheric Radiation Measurement user facility.