Developing a Lake Effect Snow Climatology for the Southern Lake Erie Snowbelt

Lake effect snow annually produces notable societal and economic impacts for residents of Northeast Ohio and Northwest Pennsylvania and challenges National Weather Service (NWS) forecasters in accurately predicting the location and intensity of the lake effect snow bands. In order to provide a better public service and improve local forecaster pattern recognition, a lake effect snow climatology by wind direction was developed for the southern Lake Erie snowbelt. Ten years of twelve-hour snowfall measurements taken by NWS observers during Lake Erie lake effect snowstorms from Fall 2009 through Spring 2019 were joined with atmospheric sounding data from Buffalo, New York and North American Model (NAM) initialization sounding data for Cleveland, Ohio and Erie, Pennsylvania before being input into a geographic information system (GIS). The 700 mb to surface average wind direction known to approximate the steering flow for lake effect snow bands were calculated for each sounding and location. Utilizing a GIS, snowfall was interpolated from spotter reports with the kriging method to create snowfall climatology maps for ten-degree increments of the steering flow from the west-southwest (250°) to the north (20°). Lake effect snowfall was found to be highly dependent on steering flow wind direction and local topography. By developing a climatology by wind direction, NWS forecasters will be able to gain confidence in winter weather forecasts, be more consistent in winter weather watches and warnings, and provide more effective and localized decision support services (DSS) to partners across the southern Lake Erie snowbelt.