Chicago's long-term forecast: Is another mild winter on the way?

Downers Grove, IL

Much of the Eastern Seaboard could be buried under snow this winter, but the Midwest could be in line for a below-normal season, according to a long-term meteorological outlook.

The Upper Midwest including Chicago is expected to receive below average snowfall this winter, according to a seasonal forecast from AccuWeather.

“Across the Upper Midwest, cities like Chicago, Minneapolis, I think, are going to miss out on the big systems down to the south as far as snowfall goes,” Paul Pastelok, AccuWeather’s lead long-range forecaster, said in the winter forecast.

Average snowfall in Chicago is 37 inches for the season.

While the rest of the Great Lakes region to the east can expect a typical winter, according to the outlook, any snow the Chicago region gets will likely come from larger “clipper systems” — fast-moving low pressure areas coming from the northwest.

Because those clipper systems move quickly, they often carry very little moisture, so they are not big snow producers, the forecast reported.

The spotty snow cover could also help keep temperatures milder than normal, but forecasters do not expect this winter’s temperature departures to be as extreme as last year’s.

A three-month outlook from the National Weather Service predicts a slight chance of above average temperatures this winter.

Elsewhere in the country, a snowy winter is possible for the I-95 corridor of the Northeast and mid-Atlantic, as well as the south Appalachians. Larger snowstorms are possible later in the season, according to AccuWeather forecasters.

But long-range predictions should be taken with a grain of salt — if not enough to cover a driveway.

This week last year, AccuWeather predicted that Chicago would see a winter with below normal temperatures and above average snowfall.

By March, the 2011-12 winter had gone down as one of the warmest on record, with an average temperature of 32.8 degrees. Just about 16 inches of snow fell all season — less than half the average mark and six inches below than the one-day total in the February 2010 blizzard.

Meteorologists acknowledge it is difficult to convey a seasonal forecast with absolute certainty.

AccuWeather, the National Weather Service and other long term predictions take several factors into account — including surface temperatures in the Equatorial Pacific Ocean, temperature differences between the Northern and Southern Atlantic Ocean, as well as historical data.

This year in particular, those factors are not painting as clear a picture.

“We actually do have a lot of uncertainty going into this particular winter,” said Kevin Birk, a meteorologist with the National Weather Service in Romeoville.

The oscillation in Pacific Ocean temperature, for instance — which can play out as El Niño and La Niña — is fairly weak this year, Birk said.

“We’re kind of flirting between El Niño and neutral,” he said. “We’re not sure how much of an impact that will have on the weather pattern this winter.”

Either way, the cold season is coming sooner than later. A front moving in from Canada this week could deliver snow to northwest Minnesota by Thursday night.