Coherent structures are known to contribute to boundary layer fluxes, influence the development of boundary layer clouds and, in some cases, lead to deep convection. Coherent structures, particularly rolls, are common in highly convective boundary layers during lake-effect events over Lake Michigan. Previous work has primarily examined the structure and evolution of coherent structures near the eastern (downwind) shore of Lake Michigan. However, numerical modeling and observational results suggest that these convective structures developed over the upwind half of the lake. No data had been available to examine the upwind conditions in which the structures evolved.
A recent field project, the Lake-Induced Convection Experiment (Lake-ICE), has collected data on the evolution of mesoscale coherent structures across Lake Michigan. The Lake-ICE data, particularly measurements from the NCAR Electra (airborne) Doppler Radar (ELDORA), provide quantitative information on the structure and evolution of convective systems in the growing boundary layer across Lake Michigan. This investigation will utilize Lake-ICE data to discuss conditions leading to the development of the observed convective structures and examine the ability of ELDORA to observe the evolution of coherent structures in a case with a shallow, lake-effect boundary layer with snow. Estimates of vertical motions and convective structure from ELDORA measurements will be compared with aircraft in-situ, WSR-88D, and satellite data.