The 2019 Farmers’ Almanac calls its frigid winter forecast “flake news.” (Farmers Almanac image)

The 2019 Farmers’ Almanac bills its 2018-19 winter outlook, which calls for “teeth-chattering cold” across much of the nation, as “flake news.” Given the publication’s checkered credibility, we’re not sure if headline is an attempt at self-deprecating humor or simply a fun a play on words. It could be both.

In any event, there’s no basis for taking its forecast seriously. Its methods are secretive, some of its predictions cannot be accurately made, and its claims to accuracy in the past are not supported.

Released this week, the Farmers’ Almanac, not to be confused with the Old Farmer’s Almanac, predicts unusually cold weather from the Continental Divide east through the Appalachians. “Near-normal winter temperatures will only be prevalent in areas west of the Rockies, the Mid-Atlantic States, and the Southeast,” it writes.

The publication touts “snow holds barred” with above-normal amounts of the white stuff piling up in the Great Lakes, Midwest, central and northern New England, the Pacific Northwest, and Mid-Atlantic.

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Its forecast seriously conflicts with the outlook from the National Oceanic and Atmospheric Administration, which generally favors warmer-than-normal conditions, except in the Southeast U.S. (It does not issue a snowfall prediction.)

Unlike NOAA, which examines current and past weather patterns and analyzes computer models to make predictions, the Farmers’ Almanac does not use modern forecasting techniques. To generate its outlook, it relies on a “set of rules” developed in 1818 which have since been adapted into a formula. “The formula takes things like sunspot activity, position of the planets, tidal action of the Moon, and a variety of other factors into consideration,” the Almanac says.

A person under the pseudonym “Caleb Weatherbee” applies the formula to make predictions. His or her identity is kept a secret to “protect” it.

It’s not to say that NOAA will be right and the Farmers’ Almanac will be wrong. There’s enough uncertainty in these seasonal outlooks that the Farmers’ Almanac ideas could prevail. Its forecast is actually not too dissimilar from that of meteorologist Joe Bastardi, chief long-range forecaster at WeatherBell Analytics, who is also predicting a cold winter over much of the eastern two-thirds of the country.

But NOAA is transparent about its methodology and the uncertainties in its outlooks, and objectively evaluates its performance after each winter.

The Farmers’ Almanac has never produced a rigorous evaluation of its past forecasts yet claims 80 percent to 85 percent accuracy based on what it is told from “longtime Almanac followers.”

In the case of last winter, the Almanac boasted its forecast was “spot-on.” But it erred in significant ways:

• It called for “below normal” temperatures in the Southeast U.S., where it was unusually warm.
• It called for near-normal temperatures and precipitation in the West, where it was warm and dry compared to normal.
• It called for “not as harsh as usual conditions” in the Northern Plains and Montana, which endured a brutal winter.

The Farmers’ Almanac also makes predictions for specific dates. For example, it is “red-flagging” the following dates for extreme events this coming winter:

• Dec. 1-3, 16-19, and 28-31 for “widespread wintry precipitation and gusty winds” in the Mid-Atlantic and Northeast.
• Mid-February for “the coldest weather of the season”
• March 20-23 for “a potent East Coast storm” that “could deliver a wide variety of wintry precipitation”

Such predictions are meaningless. Weather prediction has not yet advanced to the point in which we can say months ahead of time what specific conditions will be like in a given week or set of days. This can be done only about three to seven days ahead of time.

Some media organizations report the forecasts of Farmers’ Almanac and Old Farmer’s Almanac uncritically, without adequate discussion of their limitations. Coverage of their forecasts should include the following points at minimum:

• Forecasting long-range weather patterns is difficult and fraught with uncertainty, even using the best available science.
• Accurately forecasting specific weather events such as storms or cold snaps on particular dates months ahead of time is impossible.
• The techniques employed by the almanacs to make predictions are secretive so they cannot be objectively evaluated for their scientific credibility.
• The claims the almanacs make about their accuracy are unsubstantiated.