Snow coming to northern Illinois Thursday into Friday

A storm system developing off the Oregon coast early Wednesday morning is expected to bring 6 to 8 inches of snow to northern Illinois and eastern Iowa starting as early as Thursday afternoon and lasting through Friday.

This time around, National Weather Service meteorologist Rafal Ogorek said, they have much more confidence in the storm’s track than the one predicted a week ago.

“Our confidence is very high, higher than the storm last week that missed most of the area” and went to the south instead, said Ogorek, who is based at the agency’s Romeoville office.

What they still are uncertain of is how much wet, heavy snow the storm may bring, he said.

Jo Daviess, Stephenson, and Carroll counties are now in a winter storm warning, as is much of northeast Iowa.

McHenry, Winnebago, Boone, Lake, Lee, DeKalb, Kane, DuPage, Whiteside, and central and northern Cook counties were upgraded to winter weather advisories on Wednesday afternoon, according to the Romeoville office.

“The current forecast is somewhere in the range of 4 to 8 inches for McHenry County specifically,” Ogorek said.

The worst travel times for northern Illinois are expected from 4 p.m. Thursday to 3 a.m. Friday.

The snow will come through from the west, where it’s expected to begin Thursday morning for areas on the Iowa-Illinois line and end by Thursday night, with peak snow totals coming from 3 to 9 p.m., according to information from the NWS’s Quad Cities office.

Heavy snowfall rates, resulting in visibility restrictions and snow-covered roads, are expected to lead to hazardous travel there, particularly for the Thursday evening commute, according to the NWS.

For north central Illinois, the snow is expected to start mid-day Thursday and continue into Friday morning, with peak totals in the overnight hours.

The storm is expected to bring lower snow totals “the farther south you go and higher totals the farther north you go, toward the Wisconsin state line,” Ogorek said.

The cutoff for snow might start closer to Interstate 90, but areas as far south as Interstate 80 could see an inch of snow, he said.

The McHenry County Division of Transportation also was preparing for the snow, but warned if the snow mixes with rain, pretreating roads may not be feasible because rain would wash the treatment away, department spokesman Chris Grask said.

They use a different forecasting model, but that model also was predicting about 6½ inches of snow beginning Thursday and overnight into Friday for the region, Grask said.

“We might not get that exact accumulation,” but the model suggests that at times, a half-inch of snow per hour could fall. “We have to be proactive and hit the roads,” Grask said.

With warmer temperatures over the past few days, it may take longer for snow to accumulate on roads, Ogorek said. Lower temperatures at or just above freezing are expected Friday through Tuesday, he added.

“It will be little cooler than the last week, but warm enough for some of the snow to melt,” Ogorek said.