Automobile pollution helps spawn tornadoes

This might be the best argument in favor of Midwest HSR and local transit

Tornadoes and hailstorms may take the weekends off during the muggy summer months, according to a new study that reveals new ways human activity can inadvertently sway weather.

Scientists analyzed summertime storm activity in the eastern U.S. from 1995 to 2009 using data collected by the National Oceanic and Atmospheric Administration's Storm Prediction Center.

They discovered that tornadoes and hailstorms occurred at a rate of about 20 percent above average during the middle of the week. In contrast, the phenomena occurred at a rate of roughly 20 percent below average on the weekend.

The findings proved statistically significant—not just a random pattern—and matched up well with similar cycles seen in other kinds of storms, the study authors say.

The team then investigated Environmental Protection Agency air-quality monitoring data and noted that human-made, summertime air pollution over the eastern U.S. peaks midweek. The cycle is linked to more human-made pollution created during the five-day workweek, such as commuters driving to and from work.

More at the link. I'm joking, of course, about it being the best argument for the midwest high speed rail plan, however, it strikes me that it is still a good one. With annual damages from tornadoes resulting in billions of dollars in damage and numerous fatalities, the positive externalities of even a minor reduction in number and severity would, over the life of the system, more than repay the public investment cost.

Hat tip to David Levinson at The Transportationist.