About this time of year, an annual debate begins about winter weather predictions. Some of the most intense conversations center around the Famers’ Almanac.
Scientific American published an analysis of the accuracy of the almanac forecasts, which I found helpful. Like the fact there are two magazines: The Farmers’ Almanac and the Old Farmer’s Almanac. The difference is the apostrophe and the original publication dates, not readers’ age.
The old one was first printed in 1792, the other began in 1818. Their respective weather forecasting techniques are kept highly secret, and both have gained considerable followings, especially among, well, farmers. The comparison between those secret formulas and scientific methods used by NOAA or the UK’s Met Office is usually the focus of the disputes.
I have been impressed with the accuracy of longer-range forecasts from the National Weather Service. My favorites are the 6-10 day and 8-14 day outlooks, which certainly helped us this fall, as we struggled to finish harvest without panicking.
Almanac publishers point out they have been doing long-range predictions for decades, especially the winter forecasts. The Old Farmer’s Almanac claims 80 percent accuracy but the definition of accurate is somewhat opaque.
The article pointed out that while their forecasting techniques are kept in the vault with the Coke formula presumably, they are working in a growing volume of information from official weather agencies. One publisher disclosed they use solar activity and moon motion which most scientists consider to have a very tiny effect.
The almanac products are also backward looking – derived from past data that come close to current conditions. Weather agencies are tending more toward predictive computer models.
Climate change may make this process more problematic for almanacs as weather records for heat and precipitation are broken routinely making them unlike past years.
For a scientific publication, the authors are respectful of the almanacs. They do point out a crucial aspect of this debate: it doesn’t matter if people do not act on the predictions.
As for this winter, the almanacs generally agree with each other, and contradict NOAA. That should clear things up.
