Record tornado season brews, how ready is BV?

Thursday, May 29, 2008

Local emergency leader wants shelters for mobile home parks

Another week, another story of a rumbling train of tornadoes that obliterates entire city blocks, smashing homes to their foundations and killing people even as they huddle in their basements.

With the year not even half done, 2008 is already the deadliest tornado year in the United States since 1998 and seems on track to break the U.S. record for the number of twisters in a year, according to the National Weather Service. Also, this year's storms seem to be unusually powerful.

Buena Vista County Emergency Services Director Bob Christensen, for one, isn't surprised.

"The trainers from the National Oceanic and Atmospheric Administration (NOAA) had told me that this year was going to be the peak of a five-year cycle for tornadic activity," he said. "I don't know about all that talk about the impact of global warming and things like that, but the science does seem to support the five-year cycle theory."

While the local emergency program has worked hard in the past several years to increase readiness in BV County, there is nothing that can be done to prevent the kind of tragedy that was seen last weekend in the area of Parkersburg, where an extraordinarily powerful twister ripped apart nearly 300 homes and killed several people.

"They had their sirens going off five minutes before the storm started. People took shelter, it's just that there's almost nothing that will stand up to a tornado like that one. What could you ever do to change that outcome?" Christensen said.

It's quite early in the tornado season for Iowa, but already it has seen ther worst tornado activity in 32 years, he adds.

The only protection is common sense. "Watch when we have a tornado warning here - the first thing people will do is run outside and want to watch it. We harp on that every year to no avail," the local emergency management leader says.

Grab a radio, hit the basement or if no basement is available, move against a solid interior wall far from windows. Make sure children are trained in what to do.

"One thing that worries me is all of the trailer homes.

"If you live in one of those, and a tornado come through, you better have your checkbook balanced," Christensen said.

He supports the push to get trailer park owners to build a concrete shelter at each park, and would like to see that happen soon in Storm Lake.

"Those people need to have somewhere to go to - it's just common sense. And the park owners could always use it for storage or other purposes in the winter season," he says.

Locally, schools and nursing homes seem to do a good job of holding drills and having plans for emergencies, he feels.

Until recently, there were some big holes in the local siren warning system - some of the smaller towns had no working sirens at all. With four years of work, the system is now considered complete with six new sirens purchased and at least one working siren in every town. Storm Lake has six, Alta four, Albert City three, Newell two.

"Until recently, Rembrandt and Linn Grove didn't have any, but we have corrected that, and the system is set up now so that every siren in BV County could be set off at once from the Communications Center in Storm Lake if we have a large tornado that threatens the whole area," Christensen said.

He has also mined grant programs for five years to purchase NOAA weather warning radios - about 1,000 of the radios have been provided to public buildings and swimming pools all over the county in hopes of providing a few precious minutes of extra warning in a tornado or other disaster.

People can purchase such a radio for themselves for around $30, he says. "It's not a bad thing to have - when a tornado comes up and you are alseep, it will jog you a bit."

Given the number of tornadoes around the state, Storm Lake has been very fortunate to dodge all kinds of storms year around, he feels.

"A few years ago we had some funnels skirt the city, but they were actually cold-air dust cyclones and not real tornadoes," Christensen said. "There was a big tornado that ruined a church in Cherokee County, and one that did a lot of damage in Clay County not long ago, but I don't even recall the last tornado damage that Storm Lake would have had."

There have been boaters caught in thunderstorms this season, and lightning strikes also seem to be on the increase in the region, however.

Unlike many counties, Buena Vista does not have an organized storm spotter system. Lacking those trained volunteers, in a storm Christensen hits the roads, and some of the area fire departments will help out in an serious storm situation. "Mostly, our police and sheriff people are the front lines out there in the storm," he said.

Christensen is also patched into the ham radio enthusiast network. When bad weather strikes, those people spring into action and relay information so rapidly that it often beats the government warnings by an hour.

He regularly trains with NOAA and other emergency information providers for prevention and response, and "harps" at the public to be safe.

"You train and you train for it, and you hope like heck you never have to use it," he says.

Even veteran meteorologists cannot explain exactly why this is such a bad year for tornadoes.

"There are active years and we don't particularly understand why," said research meteorologist Harold Brooks at the National Severe Storms Lab in Norman, Okla.

The brutal numbers for the U.S. so far this year: at least 110 dead - 50 of them in mobile homes, 30 killer tornadoes and a preliminary count of 1,191 twister sightings. The record for the most tornadoes in a year is 1,817 in 2004.

"Right now we're on track to break all previous counts through the end of the year," said warning meteorologist Greg Carbin at the Storm Prediction Center.

And it's not just more storms. The strongest of those storms - those in the 136-to-200 mph range - have been more prevalent than normal, and lately they seem to be hitting populated areas more, he said. At least 22 tornadoes this year have been in the top part of the new Enhanced Fujita scale, rating a 3 (for "severe") or a 4 ("devastating") on the 1-to-5 scale.

The twister that devastated Parkersburg was a 5 - the first in the U.S. since a tornado nearly obliterated Greensburg, Kan., just over a year ago.

And if that's not bad enough, computer models show that the conditions that make tornadoes ripe are going to stick around Tornado Alley for about another week, according to Brooks.

The nagging question is why.

Global warming cannot really explain what is happening, Carbin said. While higher temperatures could increase the number of thunderstorms, which are needed to trigger tornadoes, they also would tend to push the storm systems too far north to form some twisters, he said.

La Nina, the cooling of parts of the Central Pacific that is the flip side El Nino, was a factor in the increased activity earlier this year - especially in February, a record month for tornado activity - but it can't explain what is happening now, according to Carbin.

Carbin explained the most recent tornadoes with just one word: "May." May is typically the busiest tornado month of the year.

A short-term answer is that the nation's heartland is stuck in a tornado rut with usually temporary weather conditions that can lead to tornadoes parked over the Plains, said Adam Houston, a professor of meteorology at the University of Nebraska-Lincoln. Cooler air at high altitudes and warmer moist air coming from the Gulf of Mexico are combining and settling over the region.

While scientists can forecast hurricane seasons, predicting their land-bound cousins is much harder, Brooks said. While tornadoes, like hurricanes, rely on large-scale weather phenomena, the crucial triggers are extremely local weather conditions.

On top of that, tornadoes have a "Goldilocks" issue. To make a tornado, the conditions have to be just right. Too much or too little of one ingredient and there is no tornado. For example, wind shear - when upper and lower winds are at different speeds or coming from different directions - is crucial to create a funnel cloud. Too little and there is no spin. Too much and the tornado falls apart.

And tornadoes form most often in late afternoon, between 5 and 9 p.m., so if a thunderstorm starts up early in the morning, it's far less likely to throw off a tornado, Brooks said.

As for why so many people are getting killed, Brooks suggests thinking of the landscape as a dartboard: "We're throwing more darts and throwing bigger darts than normal."

* Dana Larsen is the editor of the Storm Lake Pilot-Tribune. Seth Borenstein is a science reporter for the Associated Press.

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