The first snow of the season hit the Chicago area midday, the leading edge of a fast-moving storm that left a dusting or more of snow on the ground in some places and tied a record for snowfall at Chicago's official weather station for Oct. 22.
Around noon, snow was reported in Naperville, Downers Grove, Westmont, LaGrange and Kane County. Light snow was also reported in Aurora and the DuPage Airport, according to the National Weather Service.
A trace of snow fell at O'Hare this afternoon, the first time any snow has fallen on Oct. 22 at the city's official weather station since 1937. And since only a trace has ever fallen in Chicago on Oct. 22, the snowfall amount tied the record snowfall for the date. In addition to 1937, trace amounts of snow also fell on Oct. 22, 1935 and Oct. 22, 1922, according to the weather service.
Midway Airport weather observer Frank Wachowski reported that snow began at Midway Airport at 12:20 pm and continued until 12:40 p.m., when it changed to rain, according to the Chicago Weather Center.
"A mix of rain and snow will continue this evening. A few bursts of snow are possible which may produce minor snow accumulations, especially on elevated and grassy surfaces," the weather service said in a "hazardous weather outlook."
Areas to the north of Chicago may see only rain, according to the weather service.
The storm is expected to head out by evening, but some areas of northwest Indiana are expected to get hit with lake-effect snow tonight. Some places in Porter County could see half an inch of snow, the weather service said.
The first snow follows the first freeze of the season.
Temperatures dropped to 30 degrees at O'Hare International Airport this morning. Romeoville recorded a low of 25 degrees and Rochelle 23 degrees.
"We had a real chilly morning," said Matt Friedlein, a meteorologist with the weather service. "Very impressive for October."
Last year, no snow fell in Chicago until Nov. 12, when the city saw a dusting. The first measurable snowfall was not until Dec. 20.
The frigid air is being carried across Illinois by an "Alberta clipper,” a low pressure system that originated over the Great Plains of Canada’s Alberta Province. The center of the system is expected to cross central Illinois Tuesday evening, according to the Chicago Weather Center.
Looking ahead, far ahead, the Climate Prediction Center has updated its forecast for the winter. For Chicago, the center said there is an equal chance of winter being colder and snowier than normal or not as cold and not as snowy.
The Chicago Weather Center said that, "after crunching some numbers," this winter could see slightly less snow than average and be slightly warmer than average. The average yearly snowfall for Chicago over the last is 38.1 inches, and the average temperature for a Chicago winter--counted as from December through the end of February--is 26.4 degrees, according to the National Weather Service.
An earlier version of this story included incorrect yearly snowfall amounts and average winter temperatures.
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