| Description |
Lake- and sea-effect snowstorms can produce some of the highest snowfall rates and contribute to some of the deepest seasonal snowpacks observed on Earth, including 30.5 cm of snow in 1 hr at Copenhagen, NY and an 8 m deep snowpack at Mt. Gassan, Japan. Though the enhancement of snowfall is often large, the lowland-upland snowfall distribution within individual storms is highly variable, with heavy snowfall often crippling lowland areas as well. The factors affecting this distribution and enhancement are poorly understood, yet critical for accurate weather forecasting and future climate projections. Thus this work examines the factors affecting the inland and orographic enhancement in lake- and sea-effect snowfall in two geographically and climatologically diverse regions, the Tug Hill Plateau east of Lake Ontario and the Hokuriku Region on the west coast of the Japanese island of Honshu. The speed and direction of the flow are important in both regions, with a stronger flow yielding greater precipitation rates, a maximum displaced further inland, and a greater enhancement over the terrain relative to the shoreline. The direction of the flow is also important, with small changes in the flow yielding drastic changes in the precipitation distribution in the Hokuriku region as flow is either deflected by or surmounts the high terrain. The CAPE induced by the air-water temperature difference is also important, with greater values yielding greater precipitation rates, a maximum displaced further inland, and a greater enhancement over the terrain iv relative to the shoreline. Though only evaluated over Tug Hill, the mode of the convection is also important, with banded (nonbanded) periods seeing greater precipitation rates, a maximum displaced closer to the shoreline (further inland), and a lesser (greater) enhancement over the terrain relative to the shoreline. Collectively, these results represent a significant enhancement in our understanding of the interaction of lake- and sea-effect precipitation with downwind topography, and will be helpful in future cross-disciplinary precipitation research |
