Winter Weather Outlook 2009

Chicago - This year is on track to be one of the coolest years ever in Chicago.

This past July was the coldest since 1872. Summer may have forgotten about us, but the winter will not.

All signs point to a winter that looks much different than last year. Not as snowy and less cold. But before you leave your snow shovels in the attic, listen up. Here are the FOX Chicago Exclusive Weather Watch predictions for the winter ahead:

Last winter was cold and snowy. In fact, Chicago had its 9th snowiest and 24th coldest winter ever. And the pattern since has been wet and cold. A check of weather records with cool summers like we just had turned up climate data showing the winters that followed generally had above average temperatures and below average snowfall. Temperatures in those winters averaged about 1.5 degrees warmer, and the snow range in those winters went from 22 to 55 inches of snow.

Some signs are pointing to a less snowy and milder winter here in Chicago. But don't lose track of your hat and gloves just yet. There's more science to consider.

The most dominant influence on the winter weather forecast right now is El Nino -- the warmer than normal equatorial Pacific Ocean water temperatures. In 17 El Nino winters here in Chicago, 10 of the 17 had above average temperatures while 11 of 17 had below average snowfall. But the forecast for El Nino is expected to weaken after the first of the year. As it weakens, so will its influence of mild, drier than normal winter weather conditions.

The overall Pacific Ocean pattern called the Pacific Decadal Oscillation could then take over, sending surges of cold air from the north towards Chicago. Even the Atlantic Ocean pattern called the North Atlantic Oscillation is expected to be in a favorable phase for the jet stream to funnel cold air over Chicago as the winter progresses.

While no long stretches of sub-zero weather look realistic, Chicago will still be chilly this winter with a slightly below average temperature trend. It will be warmer in December, then colder mid January to mid February. Snowfall will be slightly below the 30-inch average with a prediction of 20 inches to 25 inches of snow December through February, which is noticeably less than Chicago had to deal with last winter !

The bottom line? It will be chilly this winter, but not as snowy. The influence of El Nino will be critical to watch. In most El Nino winters the snow is below average. But keep in mind, in the El Nino winter of 1950, the snow piled up to an incredible 55 inches.

For more information check out: Chris Sowers' Winter Weather Discussion

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Things may not be as bad as they could be, weather-wise, for the ASHM. Be your own judge and jury, or just go with the flow, but winter weather in Chicago is what it is, and we here just deal with it as something of a nuisance. In my 50 years here, I remember only two winters, 1967 and 1979, when the snow was so bad the the City shut down for a few days. Every other year it was business as usual.

Cheers,

DG