* WHAT...Heavy lake effect snow. Additional snow accumulations 3 to 8 inches, with localized higher amounts in the most persistent bands. Winds gusting as high as 40 mph will produce significant blowing and drifting with near whiteouts at times. * WHERE...Wyoming, Chautauqua, Cattaraugus, and Southern Erie Counties. Greatest snow accumulation across southern Erie County, western Wyoming County, extreme northern Chautauqua County, and extreme northwest Cattaraugus County. * WHEN...Until 3 PM EST Wednesday. * IMPACTS...Whiteout conditions are expected and will make travel treacherous and potentially life-threatening. Travel will be very difficult in deep snow covered roads. Areas of blowing snow will significantly reduce visibility. The hazardous conditions will impact the morning and evening commutes. Gusty winds will down tree branches and cause isolated power outages. * ADDITIONAL DETAILS...Lake effect snow band will slowly lift north this evening and weaken.