A rare thunder snowstorm caused near white-out conditions just in time for the evening rush and pushed the city to its fifth-snowiest winter season ever.
Thunder, accompanied by lightning, rumbled through downtown and across the area as snow fell at a "crippling" rate of 2 inches an hour, according to the National Weather Service. Visibility was down to an eighth of a mile in some places, a half mile in others because of heavy and blowing snow.
By 6 p.m. Monday, Chicago had recorded 4.7 inches of snowfall, bringing the season to a total of 66.8 inches and surpassing the full-season total for 1951-52 of 66.4 inches. Since snow records began in the winter of 1884-1885, snowfall in Chicago has topped 70 inches only three times.
The white-out conditions meant travel times on expressways were tripled for the Monday evening commute, nearly 1,000 flights were canceled at O'Hare and Midway airports and dozens of schools were closed or had scratched evening activities. Near-zero visibility was reported along some stretches of interstates 55 and 57, with numerous crashes blocking interstate exit ramps throughout the area.
No injuries were reported after a small business jet slid off a DuPage County Airport runway about 2:30 p.m., authorities said.
“We had whiteout conditions, and they kind of lost their way and went off the taxiway,” said Deputy Chief Dennis Keefe of the West Chicago Fire Department.
Five passengers and two crew members were aboard the aircraft, Keefe said. The plane didn’t suffer immediately apparent damage.
The worst of the storm hit between noon and 3 p.m. The snow tapered off by about 7 p.m., and a winter weather warning was cancelled about 8 p.m.
Storm totals of 4 to 8 inches had been forecast, and as of about 6 p.m., storm totals ranged from 3.5 inches in the Village of McHenry to 4.4 inches in Libertyville to 7.1 inches in Peotone and 7.4 inches in Romeoville, with 6 inches or more in areas as far-flung as Westchester, Lincolnwood and Elburn.
Thundersnow was reported in Champaign yesterday morning as the first wave of the storm moved through, according to weather service meteorologist Jamie Enderlen.
There were reports of thundersnow and lightning downtown and across the Chicago area as a second wave moved in from Iowa yesterday afternoon, according to the weather service.
"The were embedded with the strongest snow," said weather service meteorologist Andrew Krein.
Thundersnow can be found where there is relatively strong instability and abundant moisture above the surface, such as above a warm front, according to the weather service.
Thundersnow often produces snowfall rates in the range of 2 to 4 inches per hour, according to the weather service. While it is relatively rare, it is more common in the Great Lakes area and the Great Salt Lake.
The Groundhog Day blizzard in 2011 produced thundersnow.
The snow pack is expected to shrink later this week as temperatures rise into the 40s before plunging again next week.
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