J. Eggleston, who lives in rural Missouri and watches Kansas City TV stations, has a fascinating guest article in the New York Times "Freakonomics" blog. Over 220 days in 2007, Eggleston and his fifth-grade daughter took down the nightly forecasts of the four TV stations in town and then compared what they forecast to the weather we actually got.
What the Egglestons found confirmed what many Kansas Citians already know: Those forecasters get it wrong. A lot.
Some of his findings were pretty common sense, though it's always interesting to see them buttressed by hard numbers. His most important conclusion -- that forecasts can't be trusted beyond the second day -- I've reported on before. (A weather official in Pleasant Hill told me that all 7-day forecasts trend out to the seasonal highs and lows by the end of the week, so that a prediction of and get revised as the farthest date becomes the day after tomorrow and then tomorrow.) And on the point that drives some people around c-r-a-z-y — the constant interruptions of regular programming for severe storm coverage — the Egglestons have little to say except to note that all four stations do an excellent job of alerting the public.
I found one conclusion of the study enlightening and fun in a freakonomish way: If you were to follow the simple guideline, "Tomorrow it will not rain," 100 percent of the time, you would be right 87 percent of the time. If you followed the day-before rain forecasts of your favorite local meteorologist, you would be right between 38 percent and 60 percent of the time. And for those of you who watched a certain forecaster last night predict a 10 PERCENT CHANCE of rain overnight, about four hours before the heavens opened up and dumped rain and hail throughout the metro — can I get an amen?
Eggleston and I talked earlier today for a story on his blog piece and its reaction. He's been delighted by the comments being left at the blog (168 and counting as I write this). By far the most-repeated comment was "can you do this in my city??" Be sure to read comment #47, where Eggleston convincingly answers several doubters. (By the way, it's not a privacy thing — he calls himself "J" because in the small town where he lives, there are just way too many guys named John, including two direct ancestors: he was born John D. Eggleston III.)
