SIOUX FALLS, S.D. (AP) — Wind farms have been blamed for disrupting the lives of birds, bats and, most recently, the land-bound sage grouse.
Now the weather forecaster?
The massive spinning blades affixed to towers 200 feet high can appear on Doppler radar like a violent storm or even a tornado.
The phenomenon has affected several National Weather Service radar sites in different parts the country, even leading to a false tornado alert near Dodge City, Kansas, in the heart of Tornado Alley. In Des Moines, Iowa, the weather service received a frantic warning from an emergency worker who had access to Doppler radar images.
The alert was quickly called off in Kansas and meteorologists calmed the emergency worker down, but with enough wind turbines going up last year to power more than 6 million homes and a major push toward alternative energy, more false alerts seem inevitable.
New installations are concentrated, understandably in windy states like Texas, Oklahoma, Kansas, Colorado and Iowa, all part of Tornado Alley.
Texas, which has more tornadoes than any other state, also has the most wind power capacity.
Dave Zaff, science and operations officer with the National Weather Service office in Buffalo, N.Y., describes the wind farms 20 to 35 miles to the southeast as “more of a pimple or a blotch on your face” that 99 percent of the time will not pose a problem.
But what about those busy, high-stress periods when a meteorologist is tasked with making quick decisions as storms grow violent? In a worse-case scenario, a forecaster could disregard a real storm for turbine interference, but, more likely, would err on the side of caution, Zaff said.
“If you take a glance and then all of the sudden you see red, you might issue an incorrect warning as a result,” he said.
Problems began to surface about three years ago, and seem to occur where a wind farm is built within about 11 miles of a Doppler site, said Tim Crum, with the weather service's radar operations center in Norman, Okla.