It has been known for some time that mesoscale convective systems in the tropics may develop rotational circulations of sufficient strength that the systems transform into tropical cyclones. More recently, mid- latitude mesoscale systems have been shown to form mesoscale vortices which outlive their parent mesoscale convective system. It also has been established that these mesoscale vortices can have significant impacts on the location, timing and severity of subsequent convective weather. Due to their relatively small size and amplitude, mesoscale vortices typically are not sensed by the current operational weather system and the important physical processes are not well understood and, therefore, not accounted for in operational prediction models. Using a state-of-the-art mesoscale model, the Principal Investigator will perform a series of numerical simulations of the formation of mesoscale vortices in both mid-latitude continental and tropical maritime regimes. Results will lead to increased understanding of the physical processes by which mesoscale convective systems initially develop rotational circulations. This understanding may lead to significant improvements in our ability to forecast convective weather systems and their attendant severe weather such as heavy rainfall, hail, high winds and tornadoes.
