With an enormous winter storm bearing down on the plains, it looks like Accuweather.com's long-range holiday forecast prediction will come true, and millions of Americans won't be just dreaming of a white Christmas, they'll be living it.
"I feel from the plains eastward, more people than normal will have a white Christmas," said senior meteorologist Joe Bastardi, Accuweather's chief long-range forecaster.
At the beginning of December, Bastardi said he was predicting snowstorms that would dump snow on the eastern half of the United States later in the month. He predicted temperatures would remain cold enough to keep the while stuff around until Christmas.
Sounds eerily familiar to when an enormous blizzard, dubbed "Snomageddon," dumped several feet of snow on the Northeast last year.
Typically a quarter to a third of the United States is blanketed with white over the Christmas holiday, but Bastardi predicted about half of the country will see snow. For the most part, he will be right.
Weathermen -- and bookies -- are even betting that England, which has had unusually early cold and snowy weather already this year, will have a winter wonderland on Christmas Day.
"As it stands, this year we've got the shortest prices we've ever had, the most number of bets we've ever had," said Rupert Adams of William Hill, a British sports betting website. "It's literally a wild kingdom at the moment. Over 10,000 bets on whether it will be a white Christmas in the U.K."
Long range forecasting is a huge business and everyone from big company executives to farmers and even brides trying to plan their weddings months out are among those buying three million copies a year of "The Old Farmer's Almanac." It's been predicting the weather for 219 years.
"A perfect wedding day. Thanks for your accurate prediction," read one letter from a happy bride to the Almanac staff.
"Ours is the oldest continuously published periodical in North America, and by virtue of its popularity, we can only guess it's the most accurate, reliable and entertaining," said Janice Stillman.
Stillman is only the 13th editor of "The Old Farmer's Almanac" since it's been in publication. Its offices are located in Dublin, New Hampshire, where they have a copies of some of the first editions.
Dreaming of a White Christmas
"This is 1793," Stillman said as she pointed out a very worn book. "1793 is the first edition. It was produced in 1792."
Among several useful facts and figures -- times for sunrise and sunset, ocean tides, even poetry -- the thick book also contains a year's worth of weather, region by region.
"The almanac we put together in one year's time, so our weather forecasts, which are in each almanac, are predicted 18 months in advance," Stillman said.
So how do the almanac writers make their weather predictions months in advance when TV weather forecasters have trouble figuring out tomorrow's weather? Stillman said it's just science.
"We use scientific disciplines," she said. "We use solar science, which is the study of activity on the sun and in particular the sunspots. We use climatology, which is the study of prevailing conditions over time and we're talking decades, centuries and even longer. We use meteorology, which is the study of the atmosphere and the oscillations and ocean temperature and such as that."
The "secret formula" used to figure out weather patterns is kept in a locked black box in the museum-like office of Editor Emeritus Judson Hale, whose uncle bought the almanac publication in 1939. A meteorologist and computer models also are on site to help keep up what the Almanac boasted as an 80 percent rate of accuracy.
Some critics have said the Almanac's predictions are too broad. For example, why wouldn't New England have snow in December?
"Our forecasts are deviations from the norm and then when you get down to the specifics, you're talking about in this region over this period of time, we expect these events to occur," Stillman said. "It's kind of a broad stroke forecast for the region…with luck and a lot of study and good faith."
Paul Knight, who lectures on meteorology at Penn State University, said there is zero chance anyone has the ability to predict the weather that far in advance -- let alone the Almanac.
"If they're claiming 80 percent accuracy, if you just go by climatology, you're probably going to be right 60 to 70 percent of the time," Knight said. "So where they're claiming any skill is on those odd events they think they can forecast, but there's no proven method that they have."
'Old Farmer's Almanac' Forecasts Year's Weather
"We don't say we're 80 percent all the time," Stillman said. "It varies."
It varied wildly last winter when "Snomageddon" buried the East Coast, a historic blizzard event that Stillman admitted they hadn't predicted.
"We did not expect there to be above normal snow conditions," she said.
As for Accuweather's forecast that half the country will be covered in snow this Christmas, Stillman laughed and said, "It's entirely possible!"
ABC News' Lauren Effron contributed to this report.