The Dynamical Coupling of Convective Updrafts, Downdrafts, and Cold Pools in Simulated Supercell Thunderstorms

The initiation of second-generation convective storms by the cold pools of first-generation storms is known to depend on cold-pool characteristics such as depth and speed. It is not clear, however, how these characteristics relate back to the convective-storm components and, in turn, to the environment. Using high-resolution simulations numerical model simulations of supercells, we investigate the hypothesis that wider updraft cores result in wider downdraft cores, which subsequently lead to the development of deeper cold pools that are more likely to initiate new convection. Quantifications of the convective components show strong inter-relationships between updraft area, downdraft area, and cold pool depth. The inter-relationships are highly sensitive to the environmental buoyancy and vertical wind shear, with large convective available potential energy, strong wind shear, and a deep mixed layer ultimately contributing to the deepest (and strongest) cold pools. These results, overall, have implications on the development (or improvement) of cold-pool parameterizations in weather and climate models.