On Friday at 9:08 p.m. the National Weather Service issued a winter weather advisory in effect until Sunday at 1 a.m. for Mercer, Venango, Forest, Lawrence, Butler, Clarion, Jefferson, Armstrong and Indiana counties.

Snow is going to develop right overhead of Lower Michigan this morning. There will be steady snow eventually and widespread accumulations of a few inches. The winter weather advisory map below nicely shows where snow-covered and slick roads will develop.

On Friday at 2:14 p.m. an updated winter weather advisory was issued by the National Weather Service in effect until Saturday at 10 a.m. for Northern Blue Mountains of Oregon.