Heavy lake-effect snow in northwest Indiana continues after Chicago sees 1.5 inches overnight

Another round of snow fell in the Chicago area overnight, with lake-effect snow continuing to fall Friday morning in northwest Indiana, according to the National Weather Service.

The weather service said the lake-effect snow band will oscillate between Berrien County in Michigan and LaPorte and northeast Porter counties in Indiana Friday. Snow rates could exceed 2 inches per hour with 40 mph wind gusts, leading to “dangerous to impossible” travel conditions, it warned.

A winter storm warning in Porter is in effect until noon Friday, with a winter storm watch lasting through tonight.

O’Hare International Airport, the city’s official recording site, saw 1.5 inches of snow overnight.

The weather service warned that many roadways remain slick Friday morning, telling drivers to plan extra time for their commute.

Chicago’s forecast Friday shows isolated snow showers before 11 a.m., with patchy blowing snow before 3 p.m. The high is near 14 degrees with wind chills as low as minus 7. There’s predicted wind speeds of 15 to 20 mph, with gusts as high as 35 mph.

At night, wind chills could fall to as low as minus 9 degrees with possible new snow accumulation of about an inch.

The weather service said another brief shot of arctic air will fall upon the Chicago region tonight, with chills of minus 15 to minus 25 degrees in parts of northern Illinois. They expect another cold night Saturday, with temperatures starting to rise Sunday.

Severe wind chills can cause frostbite on exposed skin in as little as 30 minutes, the weather service said. It recommends avoiding outdoor activities if possible and wearing appropriate clothing when venturing outside. Seven people from Cook County have had cold exposure as a possible, probable or secondary cause of their death since Friday, according to the medical examiner.

By next week, temperatures will moderate. The weather service said freezing rain is possible Monday night into Tuesday, which could lead to icy roads.

Chicago’s Department of Streets and Sanitation sent out 200 salt spreaders overnight in response to the snow, and will continue to monitor main roads, Jean Baptiste Point DuSable Lake Shore Drive, bridges and overpasses, according to a news release.

At O’Hare, 57 flights were canceled and 112 were delayed as of Friday morning, according to the flight tracking service FlightAware. Another 10 flights were canceled at Midway Airport and 72 were delayed.

The weather service also warned that ice will be seen on almost all local rivers this week, leading to an increased risk of ice jams, which can cause significant water level fluctuations with little to no warning. Ice jams have caused flooding near and downstream of Wilmington on the Kankakee River and near LaSalle and Ottawa on the Illinois River.

rjohnson@chicagotribune.com