A weekend storm will bring the first significant snowfall of the season to the Twin Cities and other parts of the state where the ground had remained bare.

By the time a storm that begins late Saturday afternoon finally ends on Sunday afternoon, 2 to 6 inches of snow will have fallen in the metro area with even more to the south, forecasters say.

Then an arctic blast is expected to send temperatures plummeting below zero by early next week, with frigid conditions forecast to continue right through Christmas Day, said Lisa Schmit, a meteorologist at the National Weather Service in Chanhassen.

“It had to come sometime,” Schmit said. “It will give the kiddies something to play in over the weekend.”

The metro area has seen little snow this year, and it dodged two storms and blizzards that slammed other parts of the state. But not this time, Schmit said. And anything that falls “is going to stick around,” she said.

A winter weather advisory goes into effect at noon Saturday for the southern third of Minnesota, where 4 to 8 inches of snow could fall. The heaviest snow is expected along the Interstate 90 corridor.

“Pay attention to the forecast, especially if you’re traveling south,” she said.

Snow from 3 to 6 inches deep is expected in a wide area from the Twin Cities north, including Little Falls, Alexandria, St. Cloud and Mora. Lower amounts are predicted for the rest of northern Minnesota, Schmit said.

As the storm moves out Sunday afternoon, temperatures will sink below zero for the first time this season on Tuesday morning, with a temperature of minus 4 predicted.

But the upside is sunshine — something that has been in short supply the past three weeks.