National Weather Service: Region likely to see significant winter storm Monday

A winter storm, with the potential to produce 6 inches or more of snow, is expected to hit the region Monday.

The National Weather Service issued a winter storm warning Sunday afternoon for Winnebago, Boone and McHenry counties for 4 p.m. Monday to noon Tuesday, meaning travel may be hazardous during the Monday afternoon and Tuesday morning commutes. Northeast winds may gust up to 40 miles per hour.

The National Weather Service also issued a winter storm warning for Ogle, Lee, DeKalb, Kane, Kendall, La Salle and Grundy counties from 1 p.m. Monday to noon Tuesday. A winter storm warning also is in effect for Will and Cook counties from 4 p.m. Monday to 5 p.m. Tuesday.

“There could be a little bit of blowing snow,” Jake Petr, a meteorologist with National Weather Service Chicago, said Sunday.

According to the weather service, power outages are possible in the area “due to the combined effects of the expected wetter nature of the snow and strong and gusty winds.”

According to the weather service on Saturday, snow accumulations of at least several inches are becoming “increasingly likely” for locales near and north of Interstate 80, where a swath of 6 inches or more of snow is possible on Monday afternoon and lingering into Tuesday morning. Those south of Interstate 80 are likely to see a wintry mix, including freezing rain.

A quicker-moving system Saturday night into Sunday morning brought snow across northern Illinois, including McHenry County. The highest totals were expected toward the Wisconsin-Illinois state line. Although a light drizzle was expected after that, not much is expected until the next system moves through Monday afternoon, Petr said. After that, snow will pick up over the evening hours and peak late Monday.

Petr said Saturday there’s still some uncertainty with the system, but across northern Illinois, there’s increasing potential for amounts between 4 and 6-plus inches. On Sunday, he said McHenry County could see 5 to 8 inches of accumulation. The latest forecasts indicate that there is more potential for heavy snow between the I-80 and I-88 corridors, where 6 to 9 inches are possible, he said.

Up to one-tenth of an inch of light ice is expected along and south of I-80, according to the weather service, with a wintry mix of of freezing rain and sleet and freezing drizzle expected midday Monday into Tuesday. Snow is expected along and north of I-80, with light lake-effect snow predicted to continue through Tuesday night after the heavier precipitation earlier in the day.

Snow is not expected to start north of I-88 until later Monday afternoon, with varying rates of precipitation and likely heavy snow Monday evening, according to a 12:45 p.m. Sunday tweet from the National Weather Service Chicago.

But there still is “plenty of uncertainty,” Petr said.

“The main message here is to pay attention to Monday because there could be a decent amount of snow,” Petr said Saturday. “But the exact kind of finer details of where the heavy snow ultimately lies or ends up is something we’re still trying to figure out.”

Lake Michigan along Lake and Cook counties is expected to see impacts, with inundation of parks and trails along the lakeshore likely Monday night and into Tuesday, according to the National Weather Service. Waves of between 8 and 12 feet are possible on the lake, and action should be taken to protect property along the shore, while people should stay off trails, break walls and piers to avoid getting swept into the lake, according to the weather service.

Overall, the weather this winter has been similar to last year, which didn’t have too many big events, Petr said. Instead, it’s just been smaller events here and there, while trending a little milder temperaturewise, Petr said.

“But it’s good to reiterate that all it takes is one snowstorm to make a big change here for the winter season as a whole,” Petr said.