Multiple modes of convection in moderate-to-high shear environments

A longstanding challenge in severe weather forecasting is determining the mode that the convective storms will ultimately take. In the case of moderate-to-high shear environments this includes supercells as well as convective lines with leading and parallel stratiform linear precipitation. Previous research has generally linked selection among convective modes to the vertical wind shear and hodograph shape. However, making this determination operationally can be difficult on its own, and it becomes further complicated in light of numerous events where multiple modes of convection are experienced within a region of generally similar vertical wind shear. One such multi-modal event occurred 30 March 2006 over central and eastern Kansas. For no less than three hours, a group of isolated supercells evolved, first ahead of one squall line, and eventually between a pair of squall lines (one to the east and one to the west). During the event leading, parallel and trailing stratiform characteristics were observed with at least one of the two squall lines. These various modes were present in an area less than 300km wide from east to west, wherein morning radiosonde observations had suggested similar vertical wind profiles. The structure and evolution of this event has been investigated through a careful study of surface, upper air, satellite and radar observations. These observations, along with both real-world and idealized simulations with the WRF model, will be used to test the effects of specific features that may contribute to multiple modes of convection in ostensibly the same wind shear regime.