Misovortices and Boundaries within Long Lake-Axis-Parallel (LLAP) Lake-effect Snow Bands East of Lake Ontario during the 2013–2014 Ontario Winter Lake-effect Systems (OWLeS) Project
One of the cases from the OWLeS project featured a boundary that originated within the middle of the snow band and propagated southward through the band. Locations on the south shore of Lake Ontario, such as Oswego, NY, experienced a drop in surface temperatures of 1-2°C in less than 15 minutes with the passage of this boundary. This boundary may be similar to a gust front, only the cold outflow behind can be attributed to sublimation, not evaporation.
While it is likely that the misovortices form owing to horizontal shear instability along the low-level convergence zones in the bands, it is uncertain as to why the convergence boundaries and shear zones form. It is possible that the broader region of low-level convergence associated with the secondary circulation plays a role. Upper-air soundings, surface mesonet transects, mobile Doppler radar data, and microwave profiling radiometer data will be analyzed and presented to determine the crucial processes involved in the formation of these convergence boundaries and low-level cold pools. Boundary-layer wind direction and speed will also be analyzed to determine on which side of the band the greatest low-level convergence exists and whether this is a factor in the location and movement of these boundaries.