December is announcing its presence with authority this morning as wet, slushy, slick snow blanketed the ground overnight.

The precipitation on the ground is a mixture of rain and snow, causing slick roads and unsafe driving conditions for morning commuters in Cook, DuPage, Lake, McHenry, and Kane counties.

Meteorologists from the National Weather Service estimate between one and five inches hit the ground overnight, with areas in northern Cook and Lake County receiving the highest snowfall totals.

A winter storm advisory was in effect until noon, officials said, and an additional inch of snow could hit the ground before the snow stops later.

About 3 inches of snow fell in Mundelein. Public works crews reduced the amount of salt they used to season local roads there.

In previous years, salt trucks would drop 400 to 600 pounds if salt per mile, Public Works Director Kenneth Miller said. On Sunday night and Monday morning, they spread between 100 and 200 pounds per mile.

Despite the reduction, the roads were in good shape Monday, Miller said. "Everything seems to be going fine," he said.

Still, the wind and snow did cause some havoc on the roadways, as more than 15 minor accidents occurred since 6:15 a.m., traffic reports show.

One person suffered minor injuries this morning in a two-vehicle accident at a busy Libertyville intersection. The crash happened about 8:20 a.m. at Route 45 and Peterson Road. One person was taken to Condell Medical Center in Libertyville, firefighters said. The crash slowed traffic approaching the intersection but cars were able to get through.

Because of the conditions, authorities are asking drivers to slow down and take extra time heading into work to avoid spinning out on the slippery roads.

The winter weather is also causing headaches for travelers at O'Hare International Airports, where delays are averaging about 45 minutes, officials said, along with a handful of cancellations. Those totals are down from the amount reported overnight, where 50 flights were canceled and 100 planes delayed due to the weather.

ComEd crews are also responding weather-related outages this morning.

Pam Anton, spokeswoman for ComEd, said 3,200 customers remain without power this morning, with most outages in Lake and Cook counties.

She said that number is down from the 6,600 customers that were down as of 6 a.m. this morning, and that crews remain in the field trying to get power back on to everyone.

Daily Herald Staff Writer Russell Lissau contributed to this report.