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On May 3, 1999, one of the most powerful tornadoes ever recorded carved a path
of complete destruction near Oklahoma City. To scientists, the supertwister
held sobering lessons about the future for rapidly expanding cities in
tornado-threatened areas. Most tornadoes form suddenly and with little warning.
But now meteorologists are on the verge of a breakthrough that may solve the
puzzle of how these killer storms spawn and where they are likely to strike.
NOVA follows stormchasers as they probe the tornado's deadly secrets.
The program features noted researchers Joshua Wurman of the Center for Severe
Weather Research in Boulder, Colorado, and Howard Bluestein of
the University of Oklahoma—fellow stormchasers who have perfected the art
of tracking down tornadoes with instrument-laden vehicles designed to gather
data from as close to the churning vortex as possible. Also included is Lou Wicker
of the National Severe Storms Laboratory, who is creating computer models in
collaboration with scientists at the National Center for Supercomputing Applications
(NCSA)/University of Illinois, that provide exciting insights into the intricate
sequence of steps that goes into spawning a twister.
The goal is to provide more warning for all tornadoes, especially for rare "supertwisters,"
classed F4 or F5 on the Fujita Scale of 0-5 and packing winds
in excess of 200 miles per hour. The 1999 Oklahoma City tornado was an F5, with
winds clocked at 316 miles per hour by Wurman's mobile tracking unit. These were the
strongest winds ever documented in nature and capable of wreaking havoc that
can only be compared to the effects on the fringes of a nuclear explosion.
Contrary to popular belief, such monsters are not confined to the notorious
Tornado Alley region from Texas to the Dakotas. On April 28, 2002, a
supertwister struck the town of La Plata, Maryland, 40 miles south of
Washington, D.C. And in 1953 a supertwister devastated portions of the city of
Worcester, Massachusetts, and the surrounding area.
NOVA goes supertwister hunting with Wurman and Bluestein on a day that
threatens tornadoes all across the Texas Panhandle. Wurman heads north and
captures the first twin tornadoes ever recorded on radar. Meanwhile, Bluestein
stays in the southern Panhandle and eventually bags his own treasure-trove of
twister data.
Not to be outdone, computer modeler Lou Wicker captures the biggest prize of
all: a supertwister in the process of formation in the equations of his
program. Having input data on an F4 storm that devastated Manchester, South
Dakota, on June 24, 2003, he sees a supertwister take shape with uncanny
similarity to the real thing.
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Better prediction of tornadoes is a chief goal of the stormchasers profiled in "Hunt for the Supertwister."
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