Winter turned a month old Tuesday, and "celebrated" the occasion by unleashing a storm that threatens to dump as much as a foot of snow on region -- and leave bone-chilling temperatures in its wake.

With a winter storm warning in effect until 6 a.m. Wednesday, the National Weather Service predicts southwestern Connecticut should expect as much as 5 to 6 inches of snowfall by early afternoon from the storm, which is plowing into the area earlier than first forecast.

And as dusk falls, according to the forecast, the snowfall will pick up and the temperature will drop.

The new accumulations could be 7 to 8 inches overnight, with temperatures plunging into the single digits -- with wind-chill values propelled below zero by winds 16 to 18 mph, with gusts as high as 30 mph.

Snow is expected to ease by 9 or 10 a.m. Wednesday and the sun will gradually emerge, but the daytime high temperature is expected to rise only into the mid-teens.

Meanwhile, the storm's arrival snarled traffic throughout the area with slick roads.

Metro-North Railroad warned commuters to expect delays and possible schedule changes, and at 1:45 p.m., urged passengers to head back home as soon as possible because: "Service on railroads, subways and buses service may be curtailed or suspended depending upon significant snowfall accumulation/blizzard conditions."

Despite the storm, First Selectman Jim Marpe said he anticipates Town Hall will be open tomorrow.

He said he's told municipal department heads to tell their staffs to "make sure they use caution and consider their own safety" about coming to work tomorrow. He said he has no plans to open Town Hall late tomorrow, but that could change, depending on the amount of snow. "We're flexible," he said.

Marpe said the Board of Selectmen meeting scheduled for 8:30 a.m. Wednesday will likely start an hour later -- 9:30 a.m.

Meanwhile, classes in town schools were dismissed early Tuesday and the Westport Library closed early at 4 p.m.