How An Almanac Prognosticator Forecasts Weather

NYT (h/t Ritholtz):

Working from desk space carved out of the book clutter of a brick row house here in Emmitsburg, about a mile south of the Pennsylvania line, Mr. O’Toole endeavors to divine the weather as much as 18 months in advance. He does so with a conjurer’s brew of age-old wisdom and 21st-century technology that includes a range of tools, from a software program of astronomical data produced by the United States Naval Observatory to the meticulous tracking — through some 30 computer programs he has written — of all things lunar.

The moon matters, Mr. O’Toole says, as people who work the land discovered long ago. “They noticed a trend,” he says. “When the moon changed phase close to midnight, the weather over the next lunar week, between six and nine days, would be fair, agreeable, calm. But it was just the opposite if it occurred close to noon: snowy, rainy, stormy, disagreeable.”

After completing his calculations, Mr. O’Toole charts his predictions on postcard-size weather maps of the continental United States, drawing a map for every week. Here, then, a test: Did the prognosticator foretell Sandy, the fall’s calamitous superstorm?

He points to a blue-ink swirl that he drew on one of those small maps. In June 2011. “Tropical storm from Atlantic,” the Almanack predicted — somewhat prematurely, it turned out. “I was off by a week and a few days,” he says. “Not too bad, considering this was done 16 months earlier.”

The whole story is entertaining.  He claims that last year his forecasts were 53% right.  I'm not sure how to judge something like, "Snow, heavy south."  Is that right if it snows at all?  Anyway, it is still interesting.  I haven't picked up my 2013 almanac yet, but I will when I am Christmas shopping.