Experts: Twisters Getting Larger, Deadlier
Pastor Dale Morgan
Experts: Twisters Getting Larger, Deadlier*
No End in Sight for Tornado-Ravaged Nation
By ASHLEY PHILLIPS
May 13, 2008 —ABC News
As communities rebuild after deadly tornadoes bulldozed their way from
Oklahoma to Georgia and North Carolina over the weekend, experts say
that this tornado season is bigger and deadlier than last year's, with
little relief in sight.
Seventy-seven tornadoes tore through the country the past few days,
according to preliminary reports at the National Oceanic and Atmospheric
Administration Storm Prediction Center. In Georgia, more than 180,000
people were left without power, while 15 fatalities were reported in
Missouri.
This year's count is already twice the number of tornadoes logged during
last year's U.S. tornado season, which generally runs from mid-spring to
early summer.
"So far, in terms of the number of tornadoes, this is one of the most
active years to date," said Harold Bloom, a meteorologist at the
National Severe Storms Laboratory in Norman, Okla.
Tornadoes develop from large, powerful thunderstorms known as super cell
thunderstorms.
"One super cell thunderstorm can move many miles and can produce several
tornadoes, a family of tornadoes," said Henry Margusity, a meteorologist
at Accuweather.
"These thunderstorms will produce one tornado. It will develop, mature
and dissipate and another will fall right behind it. & You're getting a
lot of these very large thunderstorms developing."
The larger thunderstorms are producing more families of tornadoes
earlier than before and the tornadoes themselves are staying on the
ground longer than ever before in regions outside of "tornado alley,"
Margusity said.
Kansas, Oklahoma and parts of Texas officially make up this area,
although the southeastern United States experiences its fair share of
tornadoes during the season.
With more tornadoes have come more deaths. So far, 96 people have died
this year. Last year, the entire tornado season end with 81 fatalities.
"This year everything's been shifted to the east, & which is why we've
seen a higher death toll," he said. "They're happening in very highly
populated areas of our country."
"The damage that you see is just incredible," he added.
And some people are at greater risk than others.
"If people didn't live in mobile homes or if they had a more permanent
shelter to get into you could cut the deaths in half," said Paul
Markowski, a Penn State meteorologist and a veteran storm chaser.
Of the 81 people who died in tornadoes in 2007, 52 were killed in a
mobile home, according to National Oceanic and Atmospheric
Administration statistics. Markowski and other scientists suggest
creating permanent underground shelters in areas like mobile home parks
that are more vulnerable to tornado damage.
"That's what's frustrating as scientists. &The reality is for a lot less
money than the millions spent on science research, for a much smaller
investment, you could probably have a much bigger impact," he said.
Different meteorologists offer different possible reasons for the
tornado increase, from the jet stream pattern to changing water
temperatures.
"There are several things going on the atmosphere: a progressive pattern
in jet stream. & There's also plenty of fuel for these storms in the
form of a sharp temperature contrast in the United States," said Jay
Searles, a meteorologist at Pennsylvania State University. "There's been
record heat and record cold over the month of April and the first part
of May. Last year & everyone got warm in the same time. The temperature
difference wasn't as strong."
Those extremes may be attributable to La Nina, a cooling of the Pacific
Ocean, that has happened in the past year, Searles said.
"It's a normal phase," he said. "There may be a connection."
There may also be a connection to a warming Gulf of Mexico, which in the
winter had temperatures that were a bit warmer than normal, Penn State's
Markowski said. "The warmer that the ocean is the more water evaporates
to its surface," Markowski said. Moisture is a key ingredient of tornado
development.
"Years when the Gulf of Mexico is really warm, we tend to have more
tornadoes."
Despite this, Markowski stressed that there is no proven connection
between global warming and tornado development.
"People have bent over backwards to try to come up with generalizations
about tornado activity," he said. "That's one of the biggest areas of
uncertainly in the climate change community. There's no doubt that the
earth is warmer than it has been. There's extremely high confidence that
humans have contributed to warming. & What that warming means and how it
translates in tornadoes and hurricanes, especially tornadoes, we don't
know." What meteorologists do know, however, is that for now, there's no
end in sight.
Severe thunderstorms, like those that produced the weekend's tornadoes
are expected in Texas, Mississippi, Illinois and Iowa, according to Joe
Schaeffer, a meteorologist at the Storm Prediction Center. On Wednesday,
NOAA is predicting severe storms over central Alabama.
Although several meteorologists said that the tumultuous storm season
could continue even through the end of summer, accurately predicting the
outcome of a tornado season is near impossible.
"Anything beyond day three is a flip of the quarter," Penn State
meteorologist Searles said.