MIPS observations of the kinematic, thermodynamic, and microphysical characteristics of lake-effect snow bands during The Ontario Winter Lake-effect Systems (OWLeS) Field Project

Scientists and students from a dozen universities and research organizations converged along the shores of Lake Ontario during December 2013 and January 2014 for the Ontario Winter Lake-effect Systems (OWLeS) field project. The purpose of the OWLeS project is to better understand the atmospheric conditions and controlling mechanisms responsible for extreme snow accumulations downwind of the Great Lakes during winter. Mobile radar and profiling facilities, such as the UAH Mobile Integrated Profiling System (MIPS), the University of Wyoming King Air, and the CSWR Doppler on Wheels, sampled long-fetch, short-fetch, upwind effects, and down-wind persistence of Lake Ontario snow bands. Primary research objectives of the OWLeS project include, but are not limited to, the formation mechanisms, cloud microphysics, dual-polarization radar signatures, boundary layer processes, lightning characteristics, influence of downwind topography, and the dynamics of these intense lake effect snow bands.

December 2013 and January 2014 were among the snowiest months in recent memory for the lee-side of Lake Ontario, providing numerous intense long-fetch bands to study during the OWLeS field project. The Mobile Integrated Profiling System (MIPS) played an active role in sampling the internal structure of lake-effect snow bands during the OWLeS field campaign. The primary goal was to place the MIPS in the core of long-fetch bands on the east side of Lake Ontario. The MIPS sampled the core regions for extended time periods during eight IOPs, sampling a variety of radar structures quite similar to those of mesoscale convective systems and severe local storms but on smaller vertical scales. MIPS vertically pointing radar data commonly displayed Bounded Weak Echo Regions (BWERs) associated with updrafts, over-shooting tops, outflow boundaries, and cloud top Kelvin-Helmholtz waves. In one case, a snow squall developed a gust front and exhibited an overhanging weak echo region filled with updraft. Liquid water was commonly sampled in the convective core regions by the microwave profiling radiometer. Integrated liquid values up to 1 mm were common. This presentation will consist of an overview of profiling radar and thermodynamic retrievals from the UAH MIPS, as well as a discussion of the significance of these profiling observations when combined with data from scanning radars and aircraft facilities.