Creating a Climatological Snowfall Map for the National Weather Service Buffalo County Warning Area Using an Ordinary Least-Squares Regression of PRISM Data with Residual Correction Scheme

An updated 30-year snowfall climatology map of the National Weather Service Weather Forecast Office Buffalo, NY county warning area is constructed from National Centers for Environmental Information 1981-2010 Normals point data using a Geographic Information System-driven objective analysis technique, replacing the previous map that was constructed using human-expert techniques. The new technique, henceforth referred to as Ordinary LeastSquare Regression with Residual Correction (OLRwRC), involves a regression analysis of 30year normal snowfall point data across the CWA against values derived from gridded coldseason precipitation data obtained from the PRISM Climate Group. The resulting regression equation is applied to the gridded Parameter-elevation Regression on Independent Slopes (PRISM) precipitation data to create an initial snowfall map, which is then corrected using an interpolated grid of the residuals from the regression. The resulting map, while not without flaws, is a significant step forward in the representation of snowfall climatology in western and north-central New York, revealing previously unresolved details and highlighting the significant variability in snowfall that is caused by the area’s unique geography.