Prediction: More to come

Given the snow accumulations greeting the Chicago area this morning, it's perhaps not surprising to hear that for the winter ahead, more precipitation than normal is expected.

That's the word from the National Weather Service, which is also predicting that this winter will actually also be warmer than normal.

If you turn to the latest edition of "The Old Farmer's Almanac," the winter forecast is to be warmer with below-normal precipitation.

But many meteorologists, like ABC 7 Chicago's Jerry Taft, believe any seasonal predictions beyond about seven days are on very shaky ground.

"A lot of people make a business out of it," Taft said of such long-range forecasts. "I would say the science isn't there. If anyone could do it with any degree of accuracy -- and I mean any degree of accuracy -- they would probably make a great deal of money."

While certain entities -- like roadway authorities or industries that rely on natural gas consumption -- would love to be able to predict the severity of an entire winter, there's simply no way to help them that much, Taft said.

Palatine-based Murray & Trettel Inc. is one private service providing both short- and long-term forecasts to clients whose operations depend on the weather.

Murray & Trettel meteorologist John Burris said such clients can range from utility companies and construction contractors to stores wondering how many snow shovels they should stock.

Murray & Trettel would not provide its actual forecast to the Daily Herald since it's not a client.

Though the National Weather Service is predicting warmer weather and more precipitation than usual during the next three months, meteorologist Nathan Marsili said only such generalities are possible looking beyond a week out.

"(Accuracy) does go down quite a bit after seven days," Marsili said.

Those general trends are often possible to see by looking at ocean signals, he said. But he had no idea where the "Farmer's Almanac" got the information with which it purports to make long-range predictions.

According to the almanac, this winter in the Chicago area will be 1 to 2 degrees above normal on average, with below-normal precipitation and near-normal snowfall.

The almanac goes on to predict the heaviest widespread snowfalls to be in mid-December, mid-January and mid-February with heavy lake snows in early and late December, mid-January, and early and late February.

Seasonal trends through next autumn are also predicted.

The almanac claims its predictions are based on a secret formula discovered in 1792 that's based largely on solar activity and sunspot cycles.

"We believe that nothing in the universe happens haphazardly, that there is a cause-and-effect pattern to all phenomena," the almanac's Web site says. "However, although neither we nor any other forecasters have as yet gained sufficient insight into the mysteries of the universe to predict the weather with total accuracy, our results are almost always very close to our traditional claim of 80 percent."

Taft said the almanac did get lucky enough in the late '70s and early '80s for more people to believe in it, even though it then went on to be wrong for the next 10 years.

As for the week ahead, Thursday is expected to see another evening snowfall similar to Tuesday's, with just a little less snow expected, Marsili said.

About 1 to 3 more inches are expected from late Thursday's snow, compared to the 2 to 4 inches expected from last night's, Marsili said.

But don't expect an immediate thaw such as what happened after Saturday's snowstorm, he said. Temperatures aren't expected to rise significantly until early next week.