Understanding the Interaction between Short-Wave Troughs and Lake-Effect Snow Events off Lake Ontario

Shore-parallel lake-effect bands (SPBs) propose an inherent forecasting issue due to their associated snowfall rates and relatively small spatial coverage. These mesoscale precipitation events are known to interact with upper-tropospheric features such as upper-level short-wave troughs. A ten cold-season (Oct–Mar) climatology of short-wave trough passages was compiled and utilized in the determination of concurrent lake-effect events. NOAA Nexrad imagery was used to analyze changes in lake-effect band intensity, inland extent, and band orientation during and after an upper-tropospheric trough passage. Roughly one in four trough passages concurred with ongoing lake effect precipitation. SPB inland extent tended to increase when a trough was located over Lake Ontario, and the SPB precipitation region tended to shift southward during trough passage. Additionally, approximately half of SPBs took on the curvature of the 500mb height/wind field during short-wave trough passage. The frequency of concurrence between SPBs and trough passage demonstrates the need for the further investigation of the nature of their interaction.