Climatological Characteristics of Orographic Precipitation Enhancement During Lake-Effect Storms over the Tug Hill Plateau

The Tug Hill Plateau of upstate New York rises approximately 400m in elevation east of Lake Ontario and observes frequent (often heavy) lake-effect snowfall during the cool season. This study examines the characteristics of lake-effect storms over the plateau, including the degree to which precipitation is orographically enhanced during lake-effect periods (LEPs). LEPs were identified by manual examination of 0.5 degree base-reflectivity imagery from the Montague, NY WSR-88D radar for the 11 cool seasons from fall 2001 through spring 2012. Criteria for classification as an LEP included the existence of radar reflectivity features with a distinct connection to the lake, increasing intensity in the downwind direction, and a coherent, quasi-stationary structure. Our results suggest a significant enhancement of reflectivity upstream and over the plateau, as well as enhancement further downstream over the western Adirondack Mountains. This correlates well with analysis of snowfall data from COOP sites in the region. Efforts to better understand the precipitation-altitude relationship on and around the plateau during LEPs, including the causes of variations in plateau-to-lowland precipitation from event to event are ongoing and will also be presented. It is anticipated that this study will prove beneficial for the upcoming Ontario Winter Lake-Effect Storms (OWLES) field campaign, which will be held during winter 2013/14.>