Winter finally has caught up to McHenry County and other neighboring Chicago suburbs.
Despite a relatively mild season so far, residents can expect to receive 4 to 8 inches of snow this weekend, with little relief from the cold in the days to follow.
The National Weather Service issued a winter storm watch Thursday afternoon for McHenry, Boone, Cook, DeKalb, DuPage, Kane, Lake, Lee, Ogle and Winnebago counties.
The watch will be in effect from Friday afternoon through Sunday morning. The expected storm could deliver up to 8 inches of snow.
In McHenry County, snowfall is expected to pick up about 4 p.m. Friday with chances of snow showers through Saturday. High temperatures throughout the weekend are projected to be between 24 and 18 degrees, according to the NWS.
After a brief respite Sunday, snow likely will start again Monday and could continue through Tuesday, NWS meteorologist Charles Mott said.
“Once the snow stops, the cold air is going to be right there,” Mott said.
McHenry County’s snowfall is expected to arrive around the onset of a severe and punishing winter weather pattern of extreme cold and heightened storms throughout the eastern half of the U.S.
The polar vortex broke apart into three parts at the beginning of the year.
Before and during the vortex disruption, locations east of the Rocky Mountains basked in unusually mild weather for weeks. Washington, D.C., witnessed 28 days of unusually warm weather, and the first half of January ranked among the top 10 warmest on record in Minneapolis and Milwaukee.
However, the polar vortex split, which forecasters predicted in December, likely has triggered a transition toward a much more wintry pattern.
A storm last weekend, which dumped 10 inches of snow in both St. Louis and Washington, might have been one of the first indicators of the shift to harsher winter conditions.
Similarly, McHenry County residents should expect to bundle up for at least another week because another storm could hit Monday with cold temperatures and blustery winds to follow, Mott said.
“Storms are bound to happen during the winter season,” Mott said. “We’ve been quiet for a while, so basically: Welcome to winter in Chicago.”
Local municipalities already have begun preparing for the expected snowfall.
Huntley’s snowplows were loaded with salt Thursday, and street workers’ schedules were adjusted so they could stay on the roads later in the evening, village engineer Tim Farrell said.
“After the snow stops on Saturday it’s going to turn very cold, so the key is to get the roads as clean as possible on Saturday before anything can freeze,” Farrell said.
Crystal Lake public works employees will have snowplows on the roads at the storm’s onset, director of Public Works Mike Magnuson said.
“We’re prepared to go around the clock through the storm, and we’re prepared for whatever Mother Nature throws at us,” Magnuson said. “... People just need to take their time and use caution.”
• The Washington Post contributed to this report.