Alicia Roman breaks down what to expect and when with lake effect snow on the way for the Chicago area.
Snow began falling in parts of the Chicago area as many were under winter storm warnings and advisories, but which areas will be hit hardest, how long will the snow last and how much can residents expect?
The “intense band” of lake effect snow started falling across the Chicago area late Friday morning and was expected to continue into the weekend before another round of snow could take shape.
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The system could result in “prolonged” periods of snowfall and extended travel concerns.
Here’s a look at what to expect and where:
A winter storm warning was issued for parts of Cook County and northwest Indiana, with the National Weather Service warning “travel could be very difficult to nearly impossible at times” and “bands of snow may stall for hours at a time.”
Other parts of the region were under a winter weather advisory, with the potential for accumulating snow in a matter of hours.
“A quick 1 to 3 inches of accumulation is expected within just a 2 or 3 hour period,” the NWS warned.
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In Lake and Porter Counties in Indiana, a winter storm warning will go into effect at 3 p.m. Friday. There, as much as six inches or even a foot of snow could fall, with travel conditions “very difficult to nearly impossible at times.”
9:30 AM Update: An intense band of lake effect snow has moved into parts of northeast IL near the lake where rates could exceed 1-2"/hr beneath the band resulting in sharply reduced visibility and locally dangerous travel! Steadier light snow extends farther inland. #ILwx #INwx pic.twitter.com/ThMZvht1lf
In parts of Cook County where the winter storm warning was in effect, a “burst” of accumulating snow was expected through the early afternoon, at rates of 1-2 inches per hour at times, the with NWS warning of hazardous travel conditions as the snow band wobbles.
“Locally higher amounts possible with lake-enhanced snow over Lake County,” the NWS added.
Here's an updated look at the upcoming lake effect snow. If planning to travel today or tomorrow near Lake Michigan, keep tabs on the forecast and road conditions! #ILwx #INwx pic.twitter.com/EYaN63rZny
Because lake effect snow is often localized, conditions will vary across short distances. The biggest impacts will be felt in areas immediately along the Lake Michigan shoreline.
“During lake effect snow, the weather can vary from near white out conditions in very heavy snow to dry weather just a few miles away,” the NWS said. “Be prepared for rapid changes in weather, visibility, and road conditions.”
The snow bursts could lead to slick, slippery roads and hazardous conditions, with the NWS warning the conditions could impact the afternoon and evening commute.
“During lake effect snow, the weather can vary from near white out conditions in very heavy snow to dry weather just a few miles away,” the NWS warned. “Be prepared for rapid changes in weather, visibility, and road
conditions. If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency.”
While a short break in the heavy snow was possible for a period in the afternoon, another round of “intense” lake effect snow was expected to snowfall rates up to 2 inches per hour Friday evening and into Saturday morning, the NWS.
Chicago’s Office of Emergency Management and Communications urged motorists to “take extra precautions to winterize vehicles and have necessary supplies on-the-go.”
The Illinois Department of Transportation also issued an alert to drivers, asking them to “please take it slow and use extra caution during your commutes.”
The Indiana Department of Transportation told drivers to “be prepared for rapidly changing travel conditions – visibility will be greatly reduced and travel conditions will quickly deteriorate under the lake effect band.”
Some airlines have issued alerts to travelers warning of the potential for travel impacts due to the winter weather conditions.
United Airlines alerted travelers of the possibility of “operational delays, including flight delays or cancellations.”
The initial wave that began Friday morning in northeast Illinois is expected to continue through early afternoon, but the main impact from the snow is expected to move in early Friday evening and continue overnight.
“Snowfall rates may reach 1 to 2 inches per hour or higher and lead to dangerous travel within the main lake effect snow area,” the NWS warned.
The lake effect snow band will continue for several hours and could shift back to northeast Illinois Saturday, the NWS said, bringing “a period of heavy lake effect snow for several hours.”
That snow was expected to come to an end by evening, NBC 5 Storm Team Meteorologist Alicia Roman said.
In Central and Southern Cook County, a winter storm warning was in effect until midnight. That will transition to a winter storm watch through Saturday morning, the NWS said.
In DuPage, Lake and Northern Cook County, a winter weather advisory was in effect until 6 p.m. Friday
In Lake and Porter Counties in Indiana, the winter storm warning will continue through 6 p.m. Saturday.
Snow totals will vary depending on where you live, Roman said. The NWS warned of anywhere from 1 to 8 inches across the area.
East of the Dan Ryan and I-57 and in northwest Indiana, six or more inches of snow was expected, and isolated totals of up to a foot were possible.
In Illinois, counties to the west could see just a trace of snow, while counties along the lake could see between one to three inches.
To the southeast, more snow could fall, with between three and six inches possible.
Another round of snow is possible Sunday evening and into Monday morning as temperatures begin to warm into the upper 20s.
