* WHAT...Heavy snow. Additional snow accumulations 4 to 7 inches. The highest amounts are expected along the Lake Ontario shore due to lake enhancement and across the higher terrain of southern Genesee County. * WHERE...Niagara, Orleans, Northern Erie, and Genesee Counties. * WHEN...Until 7 PM EST Monday. * IMPACTS...Travel will be difficult. The hazardous conditions will impact the Monday morning and evening commutes. * ADDITIONAL DETAILS...The bulk of the heavy snow will diminish overnight, with heavy snow persisting along the southern shore of Lake Ontario Monday.