Areas near Lake Michigan could see up to a foot of snow Monday night before frigid, minus 25-degree wind chills move into the Midwest — but don’t call it another polar vortex.
A narrow lake-effect snow band — dumping as much as 2 inches of snow per hour at times — moved ashore in Cook County and northwest Indiana about 9 p.m. Monday, the National Weather Service said.
Snow accumulations could vary greatly. Areas near the lake could get 6 to 12 inches of snow, while western Cook County could see no snow at all, the weather service said.
Metra posted a service advisory to its website Monday night warning riders of anticipated delays due to the severe weather and urging them to allow extra travel time in the morning.
“Unfortunately, weather conditions beyond our control will create unanticipated delays or service disruptions,” Metra wrote in the alert. “Depending on the severity of conditions in specific areas, your train may experience delays.”
A lake-effect snow warning is in place for eastern Cook County from 11 p.m. Monday to 9 a.m. Tuesday. Lake County, Ind., is under the same warning from midnight until noon Tuesday.
The city’s full fleet of 287 snow plows and salt spreaders was deployed Monday night and will work continuously overnight to clear main roadways, said Molly Poppe, spokeswoman for the Department of Streets and Sanitation.
Poppe warned motorists to be cautious while driving as snow fell and blustery conditions developed throughout the evening.
Parts of Will County east of Interstate 57 could see 3 to 6 inches of snow, and a less serious lake-effect snow advisory is in effect for those areas from 11 p.m. to 9 a.m. Tuesday.
Traveling in areas affected by the lake-effect snowfall could be dangerous, as visibilities can drop to zero within minutes, forecasters say.
As if the snow isn’t bad enough, temperatures started to fall Monday as a cold front moved into the Chicago area. Overnight lows will range from zero to minus 4, and wind chill values could reach minus 22, meteorologists said.
A wind-chill advisory will take effect at 3 a.m. for Kane, McHenry and Lake counties, and last until 10 a.m., the weather service said.
Temperatures on Tuesday, Wednesday and Thursday will be near zero and wind chills as cold as minus 20 to 25 degrees are forecast, meteorologists said.
This particular blast of cold air is not the polar vortex itself, but rather a byproduct of the system that regularly moves through Canada and into the United States, meteorologists said.
By Friday, highs in the area are expected to climb to 24 degrees, falling to 15 at night, forecasts show.
Because of the frigid forecast, Cook County Sheriff Tom Dart activated the jail’s 24-hour weather hotline. Relatives of inmates can call (773) 674-6618 for information on posting bond and arranging a discharge, his office said in a news release. Detainees who are homeless or do not have transportation may postpone their discharge.