Mesoscale Processes and Severe Convective Weather

Abstract

Severe convective weather events---tornadoes, hailstorms, high winds, flash floods---are inherently mesoscale phenomena. While the large-scale flow establishes environmental conditions favorable for severe weather, processes on the mesoscale initiate such storms, affect their evolution, and influence their environment. A rich variety of mesocale processes are involved in severe weather, ranging from environmental preconditioning to storm initiation to feedback of convection on the environment. In the space available, it is not possible to treat all of these processes in detail. Rather, we will introduce several general classifications of mesoscale processes relating to severe weather and give illustrative examples. Although processes on the mesoscale are often intimately linked with those on smaller and larger scales, we will exclude from discussion those that obviously lie outside the mesoscale domain (e.g., baroclinic waves on the synoptic scale or charge separation in clouds on the microscale).