CHICAGO — It hits you like a punch.

A “fast-moving, nasty” snowstorm moving in from Wisconsin will leave 2 to 4 inches of snow in the Chicago area by early Thursday afternoon, said Gino Izzi, a meteorologist with the National Weather Service.

It’s already snowing heavily at O’Hare Airport and parts of the Far North Side, with the system spreading south until about 1 p.m., when temperatures will rise and change to rain, Izzi said.

There is a strong wind on the way.

“It’s a big snowstorm,” Izzi said. “Pretty intense snowfall for about two or three hours.”

Thursday’s quick storm follows “just a dusting of snow” that Chicago saw Wednesday, its first snowfall of the season, Izzi said.

This could be the turnaround in the weather after an “unusually mild” November, Izzi said.

“There’s more cold air now,” Izzi said. “We will see temperatures in the 40s and overnight lows in the 20s and 30s, more of what we should be seeing this time of year.”

More photos of the first snowfall: