Collaborative Research: Investigations of Non-Classic Lake-Effect Boundary Layer Processes

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

Advances in research and operational weather observation systems and numerical modeling techniques have led to progressive improvements in understanding of physical processes involved in the development and evolution of lake-effect snow storms. In particular recent observations taken during the Lake-Induced Convection Experiment (Lake-ICE) and mesoscale numerical models have been utilized to better understand isolated "classic" lake-effect systems that develop primarily from lake surface heat and moisture fluxes in fall and winter months. The enhanced scientific understanding of interactions between microscale and mesoscale processes in classic lake-effect systems can now be applied to more complex, and perhaps more common and intense, non-classic lake-effect storms. This collaborative research project will build on past research results and use new observations and numerical models to develop a physically-consistent understanding of complex interactions of synoptic systems and mesoscale lake-effect systems and factors controlling the coherence of, and structure along, mesoscale lake-effect convective bands. In particular the Principal Investigators will analyze data obtained from radars, aircraft, satellites and surface instrumentation and perform detailed mesoscale model simulations to study unresolved issues for non-classic lake-effect situations. Four specific research objectives are to: 1) Determine differences in the cloud microphysical structure and thermodynamics of lake-effect boundary layers that occur with and without large-scale precipitation aloft; 2) Determine the effects of a warm lake on the mesoscale dynamics and structure of moving mesoscale precipitation systems (such as associated with synoptic fronts); 3) Determine the processes by which the convective boundary layer and mesoscale circulations from an upwind lake influence lake-effect development over a downwind lake; 4) Determine the dynamic mechanisms leading to the development of mesoscale structures along lake-effect snow bands and the influence of vertical wind shear on band structural coherence. Successful completion of this research could help improve the forecast of intense lake-effect snowstorms.