By Jim Forsyth
April 1 (Reuters) – The National Weather Service on Monday
plans to begin a new initiative in Kansas and Missouri designed
to make people in Tornado Alley sit up and take notice when
potentially devastating twisters are headed their way.
Under the new system, tornado warnings will be accompanied
by stark language like, “mass devastation is highly likely,
making the area unrecognizable to survivors,” according to the
National Weather Service. Or even: “This storm is not
survivable.”
“We call this ‘impact-based warning,'”Dan Hawblitzel, a
National Weather Service meteorologist in Pleasant Hill,
Missouri, said on Sunday. “The idea is to better convey the
impact that a storm is likely to have on a community.”
Current National Weather Service tornado warnings generally
cover portions of counties and urge people in the storm’s path
to take action.
“There is quite a lot of over-warning going on; it’s kind of
the car-alarm syndrome,” said Col Galyean, a meteorologist with
The Weather Channel. “People who live in areas where tornadoes
happen frequently, like Joplin, Missouri, for example, are kind
of becoming desensitized to the warnings.”
A tornado slammed into Joplin last May, killing 161 people
in the southwestern Missouri city and causing extensive damage.
The new warnings will be tested in the two states through
Nov. 30. After that, a panel of social scientists and
meteorologists will examine the responses and determine whether
the system should be used nationwide, Hawblitzel said.
Messages such as, “Complete destruction of entire
neighborhoods is likely” may get more people posting on social
networking sites and taking instant action, Hawblitzel said.
Galyean and Hawblitzel say the more detailed warnings are
largely made possible because of a new type of Doppler radar
called dual polarization, which can measure both the horizontal
and vertical properties of a storm system and can tell
forecasters whether debris is being picked up by the storm, a
sure sign of a destructive system.
“Right now it’s tough to tell if a storm is actually causing
damage,” Galyean said. “This technology allows forecasters to
actually see inside the storm, and see different parts of the
same storm system, to better analyze its speed, direction, and
destructive potential.”
“This way we can be more sure that a tornado is heading
straight for a heavily populated area,” Hawblitzel said.
The warnings will go out to radio and television
broadcasters who issue emergency warnings, to local emergency
management personnel who activate sirens and dispatch emergency
services, and to listeners of National Weather Service radio.
In the San Antonio area last month, many people who were
caught in the path of a damaging flurry of tornadoes said they
had heard the warnings, but that it was the sight of a tornado
that prompted them to take action.
“Forecasters do worry about that,” Galyean said. “We can get
the information to the public, but the key is to get the public
to pay attention.”
(Editing By Corrie MacLaggan and David Bailey)
