The National Weather Service warned Monday night that a 15-mile wide nearly stationary band of intense lake effect snow was dumping up to 3 inches per hour on roads in southern Erie County as well as Chautauqua, Cattaraugus, Livingston and Wyoming counties.
At 10:40 p.m., winds were gusting as high as 35 mph, creating near whiteout conditions in the affected area, with the northern edge extending from Brocton to Holland to Mount Morris, and the southern edge extending from Mayville to Delevan to Nunda.
"Driving within this snow band will be extremely difficult with snow-covered roads and visibilities down to near zero at times," the weather service warned, noting that the New York State Thruway, between exits 58 and 61, and Interstate 390, between exits 4 and 7, would be affected.
It said the snow band will hit hard through midnight the southern portions of Erie and Wyoming counties, as well as the western Southern Tier north of Interstate 86.
Communities impacted included Dansville, Letchworth State Park, Springville, Perry, Westfield, Mount Morris, Gowanda, Conesus, Ashford and Arcade, the weather service said.
ALERT - Expect treacherous travel conditions south of Buffalo. Drivers are encouraged to avoid travel in this area or use extreme caution. https://t.co/1AwgWMyIdI
— NYSThruwayAuthority (@NYSThruway) December 25, 2017
Meanwhile, Interstate 86 is closed from the Pennsylvania state line to Bemus Point in both directions because of bad weather conditions and car crashes, as snow-covered roads continue to create perilous conditions for drivers throughout the region. Authorities closed the highway, also known as the Southern Tier Expressway, at about 1:20 p.m. Monday, according to a Chautauqua County Sheriff's Office dispatcher. He said most of the crashes appear to be weather-related.
To the east and north, no major roads are closed, but a travel advisory is in effect in Cattaraugus County, where officials urge people to avoid any unnecessary travel until further notice. "We've been extremely busy with accidents," a county dispatcher said.
In the southern part of Erie County, cars were off the road in towns such as Concord and Holland, where the snow was particularly heavy. "The roads are snow-covered and slippery, and the crews have been notified and they're out there," County Dispatcher Sajdak said, without giving his first name. "We've done everything we can."
The East Aurora Police Department issued an alert at 5:44 p.m. Monday requesting motorists make no unnecessary travel in the Town of Aurora due to hazardous road conditions, according to the Niagara International Transportation Technology Coalition.
Aurora is seeing conditions with very limited visibility and extreme blowing conditions. We have 3 trucks on until the midnight hour when we anticipate putting 7 on. Roads are covered and treacherous to traverse. Travel is severely limited at this time.
— Erie County DPW (@ErieCountyDPW) December 26, 2017
In other areas, the lake-effect snow was causing some minor crashes or vehicles off the road, but no major issues.
"It's ugly, but that's par for the course," said a Town of Eden police dispatcher. "It's just a routine lake-effect event."
In Genesee County, the sheriff's office lifted a travel advisory for the entire county at 10 a.m. Monday, saying that road conditions had improved.