It was a slow slog to work for many motorists Wednesday morning, but the worse commute this week may be yet to come.

Snow is expected to return Thursday, starting with afternoon flurries and intensifying overnight. By Friday, some locations could see 5 to 9 inches of new snow.

A winter storm watch for Lake, Porter and LaPorte counties will be in effect from 9 p.m. Thursday to 11 p.m. Friday, according to the National Weather Service.

The forecast comes after a week of snow.

Total snow cover ranged from 5.5 to 7 inches in Lake County, from 4 to 9 inches in Porter County and 6 to 8 inches in LaPorte County, according to data posted Wednesday morning on the Community Collaborative Rain, Hail and Snow Network.

Jasper and Newton counties remained under a travel advisory, which means routine travel could be affected because of hazardous conditions.

Officials warned drivers to allow extra time for travel, slow down and make room for plows and emergency vehicles.

Highland warned residents that snowfall had exceeded 1 inch, so parking on public streets was prohibited. Cars cannot be parked on Portage streets after 2 inches of snowfall, police said.

The Porter County Sheriff's Department said vehicles parked on streets in unincorporated areas will be towed if more than 2 inches of snow has fallen and the vehicles are not moved after a green warning ticket is issued.

Indiana Department of Transportation's Northwest District said on Facebook early Wednesday more than 170 crews have been plowing and salting roads for the past 48 hours, but some areas remained slick.

"Overnight storms like these are especially tricky for us to completely clear the way and limit slick spots. So, you definitely want to plan plenty of extra time this morning. It's nasty out there in most areas," the department said.

Several schools announced delays and closures.

Michigan City Area Schools announced the Future Careers Expo scheduled for Thursday at the A.K. Smith Career Center was canceled because of school delays this week, participants with the flu and weather concerns. The event will not be rescheduled.

Low temperatures Thursday could fall to near zero, with negative single digit wind chills.