The National Weather Service issued an updated report at 3:48 a.m. Friday on heavy snow through 4:30 a.m. for Cayuga, Tompkins and Cortland counties.

“At 3:47 a.m., a band of heavy snow was located near Smithville Flats, or 10 miles southeast of Marathon, moving west at 55 MPH,” the weather service said.

Locations affected by the warning include Binghamton, Vestal, Cortland, Johnson City, Endicott, Kirkwood, Conklin, Maine, Owego and Homer. This includes the following freeway exits: New York Interstate 81 between 1 and 13. Interstate 86/Route 17 between 63 and 82. Interstate 88 between 1 and 6.

The weather service notes: “Conditions can deteriorate quickly in winter weather. Be prepared for snow or ice-covered roads. Slow down and allow extra time to reach your destination.”

Advance Local Weather Alerts is a service from United Robots, which uses machine learning to gather the latest data from the National Weather Service.