"Optimism bias" could kill you
The National Weather Service is turning to social science research to figure out why people don't take their severe weather warnings seriously enough, fast enough.
A recent review on the forecast performance and public response during a severe tornado outbreak last year found that the weather warnings were issued in plenty of time for people to take shelter - 17 minutes on average. And there had been days of weather broadcasts about the potential for deadly storms before they finally materialized.
But 57 people died anyway, and 350 were injured. Property damage in the outbreak on Feb. 5-6, 2008 came to $400 million.
It was the second-deadliest rash of tornadoes on record in the U.S. A total of 82 twisters swept through nine Southern states. (The photo at right is from the 2002 tornado in La Plata, Md.)
In reviewing the aftermath, the NWS found that two-thirds of the people who died were in mobile homes, and 60 percent did not have access to a basement or a storm shelter. Some of the survivors interviewed said they discounted the danger because they didn't consider February to be part of the traditional "tornado season." Others said they spent time trying to confirm the tornado warning, and sought shelter only after they saw the funnel cloud coming.
Many others, the report said, minimized the danger they were in due to what sociologists call "optimism bias" - the tendency to be over-optimistic about the outcome of one's plans. Or, put another way, it's the belief that bad things only happen to "other people." That reminds me of the comment reporters often hear from survivors of violent crime or violent weather - "You read about these things happening to other people, but you never think it will happen to you."
Well, it can, and it does.
The post-storm assessment team recommended that the NWS improve the wording and "call-to-action" statements in their warnings to "more effectively convey the urgency and danger of the message. The agency will also continue using social science research ... to further understand people's interpretation of and response to severe weather situations and to improve public response..."
Perhaps that led to the language in the memorable warning issued last September when Hurricane Ike was approaching Galveston, Texas, with a predicted 20-foot storm surge:
"Persons not heeding evacuation orders in singe-family, one- or two-story homes will face certain death," it said.
The storm surge wasn't quite that high, but it swept parts of the Texas coast clear, and dozens of people died. More vanished. Here's Bolivar Beach: