* WHAT...Mixed precipitation this afternoon changing to all snow by this evening. Additional snow accumulations 3 to 5 inches across the Tug Hill Plateau, with 1 to 2 inches elsewhere. Ice accumulations around a few hundredths of an inch, and up to a tenth of an inch close to the Saint Lawrence River. * WHERE...The Eastern Lake Ontario Region. The greatest snow accumulations will be across the Tug Hill Plateau. The greatest ice accumulations will be close to the Saint Lawrence River. * WHEN...Until 7 AM EST Saturday. * IMPACTS...Roads, and especially bridges and overpasses, will likely become slick and hazardous. Plan on slippery road conditions. The hazardous conditions will impact the Friday evening commute.