DECATUR - While it may not yet officially be winter, daily temperatures and the frozen precipitation that fell early Monday indicate it's pretty much here.

So what do the official forecasters suggest about the coming months?

First of all, it's winter. So, yes, it's going to be cold.

Second, snowfall will happen, probably a normal amount, which, according to the National Weather Service, usually is 25 to 30 inches annually.

Third, ice, maybe. That's more of an unknown. That kind of prediction isn't an easy one to make, said Dan Smith, Weather Service meteorologist in Lincoln.

"Ice is very critical to what the temperatures are going to be doing," he said, especially those just two or three days in advance of an ice event.

However, comparing two well-known weather prognosticators shows their overall winter predictions aren't far apart.

The Old Farmer's Almanac's long-range weather forecast suggests a very cold period that started around Thanksgiving, with temperature seesawing through March.

The Weather Service outlook indicates a December that began colder than normal, with the second half warming, Smith said.

"The coldest periods will occur in December, early and mid-January and in early and mid-February," predicts The Old Farmer's Almanac.

According to the Weather Service, there's between a 40 percent and 50 percent chance that temperatures will be above normal, said Llyle Barker, also a meteorologist based in Lincoln.

"Overall, the trend as far as the outlook is concerned is pretty close to where it should be," continued Smith. "There are equal chances for above- to below-normal temperatures."

Janice Stillman, editor of the almanac since 2000, said one thing to remember about almanac predictions is they are made 18 months in advance.

"(The prediction) doesn't reach the public until it's on the newsstands," she said, though almanac forecasts can be similar to Weather Service predictions. "The formula that we use to make the forecast is proprietary," Stillman said.

But she revealed the basis upon which forecasting is made: solar science, the study of activity on the sun; climatology, the study of prevailing conditions for decades and centuries; and meteorology, the study of the atmosphere.

And the almanac forecasting includes a prediction about global warming.

"In short, that global warming is over," Stillman said. "This is one way to distinguish us from the National Weather Service and others, as well."

She explained the prediction is based on the sun not being a constant star, and one of the measures of that is the number of sunspots that occur.

"(The year) 2008 has been a period of few sunspots. We've been in a quiet period," she said.

"Historically, that indicates a cool period to follow, not necessarily this winter, but perhaps in the ensuing period."

There is, however, one qualification in this prediction: greenhouse gases.

"What we cannot predict is greenhouse gases, because they are not on record," Stillman said.

And, she added, the unknown is how greenhouse gases may offset solar activity.

amannlein@herald-review.com|421-6976