MINNEAPOLIS (WCCO) – The Farmers’ Almanac is out with its annual weather forecast for the coming years. This time, it’s predicting a “piercing cold” winter with “normal snowfall” for the Upper Midwest.

There are actually two Farmers’ Almanacs: the Farmers’ Almanac has been predicting since 1818 and the Old Farmers’ Almanac since 1792. Both say they average 75- to 80-percent accuracy, but some meteorologists put the Old Farmers’ Almanac to the test, saying it’s probably closer to 50 percent.

WCCO Chief Meteorologist Chris Shaffer says the science is not solid.

“What they do often times is look at trends, which sometimes can happen,” Shaffer said. “Other times, it’s just a guess.”

The specific formula is kept secret, but Farmers’ Almanac Editor Peter Geiger says it’s based on sunspot activity, planet positions and the effect of the moon on the Earth.

According to Shaffer, meteorologists have come a long way when it comes to weather forecasting.

“Within three days, we can nail it, like, in the 90s, and sometimes the high 90s,” he said. “You get past three days, you start to see your accuracy slip back to maybe the 80s or so. And then when you’re trying to forecast a full week, by the end of that week you’re more looking at trends.”

This year’s Farmers’ Almanac made a splash when it predicted an intense storm, heavy rains and strong winds for next year’s Super Bowl, which will be held at the outdoor MetLife Stadium in New Jersey.

As for next year’s State Fair weather prediction? Expect chilly Canadian air and heavy rain.

Heather Brown