Are tornado sirens used too often?
09/26/2011 6:27 AM
09/26/2011 6:27 AM
The deadliest year for tornadoes in decades has prompted calls by weather and emergency officials for sweeping changes in how warnings are issued and tornado sirens are used.
The need for change is reinforced by a government assessment of the warnings issued before and during the May 22 Joplin tornado. That storm killed 162 people — the most by a single tornado since formal tornado statistics began in 1950.
"We're going to have to really rethink what we're doing," said Butler County Emergency Management director Jim Schmidt.
"This has been a wake-up call for a lot of people. We're not as safe as we thought we were."
Tornadoes have killed more than 540 people this year — the most in 75 years. More than 300 died on April 27 alone, when 202 tornadoes touched down in 14 states in the southeastern U.S.
And then came that Sunday night in Joplin.
The widely held perception that tornadoes could no longer generate high death tolls because of more effective and accurate warnings has been shattered, officials say.
"I think all of us in this business... have done some soul-searching," Schmidt said. "It was just like it punched you in the gut: 'How could this happen in this day and age?' "
The Joplin assessment team interviewed dozens of survivors, most of whom did not immediately seek shelter upon hearing the initial warning.
Residents routinely sought some sort of independent confirmation of the threat, said Richard Wagenmaker, meteorologist-in-charge at the Detroit branch of the National Weather Service, who headed the assessment team.
Many went outside to look around.
"With a fast-moving tornado," Wagenmaker said, "it's the worst thing you can do."
The Joplin tornado was invisible to many residents because it was shrouded in rain.
"There were numerous accounts of people running to shelter in their homes just as the tornado struck despite significant advance warning of the risk," the report states.
Mike Smith, senior vice president of AccuWeather Enterprise Solutions, blames those delayed efforts to find shelter on the fact that Joplin also sounds tornado sirens any time severe thunderstorm winds are expected to exceed 75 mph.
"What happens is, you've confused everyone" because they don't know if the sirens mean a tornado is coming or just strong winds, Smith said.
After reading the government report, "there is now no doubt in my mind that that practice cost lives" in Joplin, he said.
Many cities use their sirens for something other than a tornado bearing down, Smith said.
"Nationally, there needs to be a rethinking of how tornado sirens are used," he said.
But Schmidt said he understands and endorses the use of tornado sirens when strong winds threaten areas where camping and boating are popular.
Butler County sounds the sirens in El Dorado and next to El Dorado Lake any time confirmed winds of at least 80 mph are moving into the area.
"We can have 40,000 people at the lake," Schmidt said. "If there are 80-mile-an-hour winds coming and you're in a camper, it is a whole lot different than if you're in a nice brick house."
Sedgwick County, which includes Wichita, sounds its sirens only when a tornado warning is issued.
The government study of the Joplin tornado recommended that storm warnings be "impact-based" so residents can more clearly understand the potential danger.
An example of that, Schmidt said, would be to say a storm has the potential for hail the size of baseballs, which could do significant damage to vehicles and other property.
"Maybe it is time to take a look at how often we warn on non-life-threatening events," Schmidt said. "So a thunderstorm is going to have 58-mile-an-hour winds. Is that going to kill anybody? Probably not.
"Maybe we need to save the warnings for when we have to say, 'This thing could kill you — get underground now.' "
The National Weather Service should work with partners who can provide warnings through mobile communication technologies such as text messages and smart phone alerts, the report said.
That includes encouraging equipment upgrades that will allow emergency managers to sound only those tornado sirens in the direct path of a threatening storm.
Many jurisdictions — including Sedgwick County — have an "all-or-nothing" alert system, meaning sirens are sounded whenever any part of the county is threatened.
But Sedgwick County is accepting bids to upgrade the siren system by next March, emergency management director Randy Duncan said.
"Wichita is doing things right," Smith said.
Butler County already has that technology.
The government report says better language for warnings is needed, too.
As a massive tornado closed in on Greensburg shortly after sunset on May 4, 2007, the Dodge City branch of the weather service issued a tornado emergency for the town.
That had never been done before, but the alert drove home to Greensburg residents how serious the threat was.
Officials have credited the alert and residents' quick and appropriate steps to take shelter with keeping the death toll low even though the tornado — an EF-5 that was 1 3/4 miles wide, with sustained winds topping 200 mph — all but wiped the Kiowa County seat off the map.
Another tornado emergency was issued by the weather service as a large tornado bore down on Tuscaloosa, Ala., on April 27.
But the Joplin assessment discovered the tornado warnings and severe weather statements had no enhanced language to accurately portray that immediate action was necessary to save lives.
No easy answers
Wagenmaker said he will form a team to explore how to implement the report's recommendations.
That includes finding language "that makes warnings more credible and prompts people to more appropriate action," he said.
Yet early warnings and precise language won't guarantee that people will do what they should when severe weather threatens, Schmidt said.
Joplin survivors told the assessment team that they believed there was a "protective bubble" over the city, that bad storms always seemed to miss it, that the sirens sounded all the time and nothing bad ever happened.
"That's what we heard from people in the Super Tuesday outbreak," said Schmidt, who was on the assessment team for the two-day outbreak in the southern United States in February 2008.
"We'll hear the same thing from Andover residents today," even though a massive tornado tore through the town in 1991, killing 13 people at the Golden Spur mobile home park.
The town has nearly tripled in size since then, he said, and most current residents didn't live there when that tornado hit.
"You have to be very careful in making changes, no matter what you do," Schmidt said. "It's going to take a lot of time to get the message out.
"People don't pay attention to what we do now," he said. "How do we change that? How do we convince them, instead of going outside where the tornado is, to actually take shelter?
"There are no easy answers, no matter what change you make."