Sunny outlook

October 6, 2015

ThinkstockPhotos-179711727NIU meteorology professor David Changnon has a seasonal forecast that might brighten the day of folks in the Chicago region, which has been slammed with two consecutive brutal winters.

Just to jog your memory: Last February’s average temperature of 14.6 degrees Fahrenheit in Chicago tied the month’s record for cold.

The 2013-14 winter in the region was even less tolerable. It was characterized by two extreme “polar vortex” cold-air outbreaks bringing historically cold weather into the entire Midwest. The cold and snow contributed to an economic slowdown, caused tens of thousands of flight cancellations and created a plethora of potholes and water main breaks.

Changnon is predicting the northern Illinois region will get a break from the bitter cold and excessive snow this coming season.

David Changnon

David Changnon

“There’s a much greater opportunity for a warmer and somewhat dryer winter,” says the Board of Trustees Professor in NIU’s Department of Geography.

Specifically, Changnon estimates a 60 percent probability that the December-through-February season will bring above-average temperatures. There’s a 30 percent chance for an average winter and only a 10 percent likelihood of another bitter-cold nightmare.

We have a strong El Niño to thank for the sunny forecast, Changnon adds.

El Niño events are characterized by unusual warming of sea-surface temperatures in the equatorial Pacific Ocean. The warming alters the location and magnitude of the polar front jet stream, which impacts winter weather conditions in North America.

“Waters in the equatorial Pacific began to warm at a rapid pace early this year, in the late spring and early summer,” Changnon says. “The magnitude of ocean warming is reminiscent of strong El Niño events that impacted the 1982-83 and 1997-98 winters. They were two of the strongest El Niños in the last 65 to 70 years—and this El Niño could rival those events.”

ThinkstockPhotos-124823290In 1982, Chicago’s Christmas Day high temperature was 64 degrees. The winter of 1997-98 ranked among the warmest on record for the Midwest.

Some caveats do come with Changnon’s long-range forecast for the coming season, however.

“There is no absolute certainty with weather, no two El Niño events are ever exactly alike and other factors will contribute to our winter,” he says. “One of the big wild cards this year is the pool of warm water in the North Pacific Ocean, off Alaska’s southern coast. It had an incredible impact on our last two cold winters and still exists. But I think this strong El Niño will likely trump everything else.”

Keep in mind that a warmer winter doesn’t mean a complete absence of snowy days and bitter cold—so don’t bury your winter coat in your closet just yet. But Changnon says he predicts warmer overall average temps, possibly in the range of 3 to 6 degrees Fahrenheit above the winter average in our region.

ThinkstockPhotos-464401786“Six degrees might not sound like all that much, but it would have huge ramifications for consumers and the economy,” he says.

Consumers would see cost savings on natural gas for heating, and even gasoline prices could see a downward trend. Municipalities would stand to save money typically spent for snow removal, pothole patching and truck and equipment maintenance. Emergency services would potentially respond to fewer accidents. The construction season could last longer. And retail sales stand to benefit, since warmer weather brings out more shoppers.

Of course, with the good always comes some bad.

A warmer winter wouldn’t be great for the Midwest ski industry. And the effects of El Niño in other parts of the country could be negative.

“In the upper Midwest, strong El Niños are generally related to positive impacts,” Changnon says. “However, the Southwest, especially California and Arizona, where more frequent heavy storms are expected, could be negatively impacted by weather events such as flooding and mudslides.”

Tom Parisi, NIU Media and Public Relations