Tornado season returns to area

March 16, 2009 08:46 pm

— By Wally Kennedy
wkennedy@joplinglobe.com
When a twister threatens the village of Airport Drive, Don and Lanette Striegel are among the first to hear the warning.
“The tornado siren is in the yard next door,” Lanette Striegel said. “We hear it inside our house loud and clear.”
The Striegels do not have a basement. When the siren sounds, they take shelter in an interior hallway in their house and hope for the best. There is no village storm shelter.
That changed on Monday, when the Striegels had a concrete storm shelter installed in their back yard. The 6- by 8-foot shelter can hold several people.
“We’ve been thinking about doing this for years,” Don Striegel said. “We saw that storm that hit Carl Junction (in May 2003). It passed over that way, and we could see the debris flying in the air.
“It just seems like we’re getting storms more frequently lately and that they are more powerful.”
Above the average
Striegel is right about that. The United States logged 1,690 tornadoes in 2008 that caused damage in excess of $1.8 billion. The number of twisters in 2008 was well above the 10-year average of 1,270, and it ranks as the second highest annual total since reliable records began in 1950.
The tornadoes caused 1,700 injuries and 125 deaths, making 2008 the 10th deadliest year since 1950, according to the National Climatic Data Center in Asheville, N.C. The record was set in 1953, when 519 people were killed.
The May 10 tornado that swept through Picher, Okla., and across Newton County was among the 10 most powerful tornadoes to strike in 2008, according to the National Storm Prediction Center in Norman, Okla. The tornado, which packed winds of nearly 175 mph and tracked for 74 miles, claimed six lives in Picher and 14 in Newton County.
Lee Sandtorf, who installs the concrete shelters, said business is always brisk after a tornado like that one.
“Typically, we don’t hear a thing till we get a storm and people are reminded what a tornado can do,” he said. “We had a lot of interest and people asking about them after that tornado last year, and then it gradually tapered off. It’ll pick up again after the next storm.”
On average, Southwest Missouri experiences 10 tornadoes per year, with Jasper County leading the state in the total number of confirmed tornadoes, according to Gene Hatch, a climatologist with the National Weather Service station in Springfield.
Last year, Missouri logged 101 tornadoes. The annual average between 1961 and 1990 was 27, he said.
On Monday, Sandtorf installed the Striegels’ storm shelter after installing one near Columbus, Kan. Both were for residences.
“It generally takes about 2 1/2 hours to dig a hole, put the shelter in the hole and clean up,” he said. “A unit typically starts at $2,350. It depends on the job after that. It costs more if we hit rock while digging, if we have to go far to put one in or if it’s in a tight spot that might add more labor.”
La Niña
When compared with last year, 2009 is off to a slow start when it comes to tornadoes. But, the ingredients are there for another stormy spring.
New research has shown a connection between the occurrence of a La Niña in the Pacific Ocean and volatile weather in the Midwest. La Niña, a periodic cooling of waters in the Pacific Ocean, is the flip side of the better-known El Niño phenomenon.
La Niña shifts the polar jet stream into a position in which storms from the west collide with moisture from the Gulf of Mexico. When that happens, the jet stream — a shifting river of air at high altitudes — brings an abundance of warm, moist air from the Gulf of Mexico into the Midwest. That, coupled with high winds and a storm system with cooler air from the west, provides the primary ingredients for violent weather.
The research found that tornadoes during a La Niña are stronger and track greater distances.
Greg Carbin, warning coordination meteorologist with the Storm Prediction Center, said the La Niña-El Niño cycle was in a neutral phase until January, when a new La Niña started to show its influence. Last year’s La Niña was the strongest in a decade.
“We have a La Niña that’s ongoing right now, but it’s not quite as pronounced as last year,” Carbin said. “It is expected to weaken this spring. That connection between La Niña and severe weather in the Plains is tenuous. But it was certainly the case last year. It was a busy year all around.”
Unlike last year, the country so far this year has experienced relatively quiet conditions for severe weather.
“Thunderstorm activity is expected this spring,” Carbin said. “It gets more active regardless of whether there’s a La Niña in place. Another ingredient that is a factor, and it’s closer to home, is the sea surface temperature in the Gulf of Mexico.
“When that temperature is above normal, it helps the return of moisture to the Plains states. It provides the fuel for thunderstorm activity. Those temperatures are now slightly above the long-term normal.”


Spotter training

The Joplin-Jasper County Emergency Management Agency will present its annual severe-weather spotter class at 6:30 p.m. Wednesday in the basement of Joplin City Hall, 602 S. Main St. The free class is open to anyone who is interested in learning more about the severe weather that occurs in the Four-State Area.

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