Freezing rain fell across the Northland this morning, coating roads, sidewalks and trees with ice and forcing a number of school districts to delay or cancel classes.

Duluth, Superior and Hermantown schools were closed Friday, along with Lake Superior College. Many other Northland school districts delayed or canceled classes; find a longer list of closings and delays here.

St. Louis County Public Works urged extreme caution on the county's many gravel roads because the rain freezing to the snow pack on the roads has made them extremely icy. Most blacktop and paved roads in the Twin Ports are in fair condition, although some sidewalks are very slippery.

The National Weather Service upgraded the freezing rain advisory to an ice storm warning for Itasca, Koochiching, Cass and Beltrami counties, where more-steady freezing rain continued overnight and led to greater ice accumulations. All the warnings and advisories for freezing rain expired at noon.

The Minnesota Department of Transportation reports many icy roads in Northeastern Minnesota, especially in areas north and west of Duluth. The Wisconsin DOT reports some ice-covered highways in Northwestern Wisconsin.

Heavy snow possible

After the freezing rain ends today, snow is forecast to develop across parts of the Northland. The heaviest snow is expected north of the Iron Range, where a winter weather advisory is in effect for northern St. Louis, northern Itasca and Koochiching counties - including Ely, International Falls and Bigfork - from 6 p.m. Friday to 4 p.m. Saturday.

The Weather Service is forecasting snowfall of 3 to 7 inches in the advisory area. Lesser snowfall of 1 to 2 inches is expected for the Iron Range, with about an inch of snow possible in the Twin Ports.

Temperatures are forecast to reach the mid- to upper 30s today, and then the 20s for highs on Saturday before taking a plunge later in the day. Lows Saturday night may fall below zero in many areas.