Operational Forecasting of Lake Effect Snowfall in Western and Central New York

Abstract

Lake effect snowstorms frequently produce heavy snow in western and central New York State during the late fall and winter months when the waters of Lakes Erie and Ontario are relatively ice free. Mesoscale snowbands account for most of the snow. The depth of the snowfall can vary as much as 100 cm in 50 km. An Overview is presented of some of the procedures that the National Weather Service Office in Buffalo uses to forecast lake effect snow. Forecasters at the office developed a computer program for the Automation of Field Operations and Services (AFOS) that provides guidance for forecasting lake effect snow. The program includes the compilation of forecasts for wind direction and temperature in the lower troposphere at Buffalo. It also calculates the fetch across each lake, and the change in wind direction through the lower troposphere. The program requires input parameters that are computed from one of the two operational numerical models of the National Meteorological Center, and the average surface temperature of each lake. The output is used as guidance by the forecasters to determine the potential for lake effect snow and the most likely location of the snowbands.