Orographic Influences on Lake-Effect Snowstorms

Orography has a dramatic influence on lake-, sea-, and ocean-effect snowstorms from the Great Salt Lake (GSL) of northern Utah, which is surrounded by topographic barriers that rise up to 2000 m above lake level, to the Laurentian Great Lakes, where up to 500 cm of snow falls annually over modest topographic features such as the Tug Hill Plateau east of Lake Ontario. Beyond North America, lake-effect storms frequently affect western Japan during the winter monsoon and represent a forecast challenge for the mountain venue cluster of the 2014 Olympic Winter Games in Sochi, Russia, which lies east of the Black Sea.

In this presentation, we will review the influence of lake-effect storms of mountainous regions around the world and examine recent advances in our understanding of lake–orographic interactions over the Great Salt Lake Basin. In particular, we will discuss: (1) how upstream and downstream orography can influence the development of lake-effect snowstorms, (2) how synergistic interactions between lake and downstream orographic processes can be crucial for precipitation development over the Great Salt Lake Basin, and (3) the factors influence the ratio of lowland and mountain snowfall, leading to what the Japanese call “satoyuki” (lowland) and “yamayuki” (mountain) storms. We will also describe plans for the NSF-sponsored Ontario Winter Lake-effect Systems (OWLeS) project, which will be held during winter 2013/14 and includes a component examining orographic enhancement over the western slope of the Tug Hill Plateau, which rises 500-m above Lake Ontario.