Super Outbreak ’74: How the Warnings Have Changed
The WIBC News Special “Super Outbreak, Super Prepared” airs Thursday at 7 on 93 WIBC.
INDIANAPOLIS–In 1974 the idea of using radar to track tornadoes was about 20 years old. The scopes that forecast offices used had been developed in the late 1950s. When the Super Outbreak happened on April 3, meteorologists knew to look for a hook echo that indicated a tornado.
The iffy hook echo
The main problem with that is that the hook echo didn’t always show up.
Radar of the type that was used then scanned for precipitation only. If a tornado was wrapped in rain, radar might only pick up a blob, with no indication that the storm was rotating. The hook echo came from the rain that was picked up rotating around the twister.
“They were not Doppler radars. They were pretty crude. All you could see was the shape of the precipitation pattern,” said Dr. Greg Forbes, severe weather expert. He was part of the team that surveyed the tornadoes from the ’74 outbreak.
“They were not computerized. So, all you got was black and white on the screen. You didn’t even get the kind of variations of storm intensity that you get now,” he said.
The crude warning system
Forbes said that even more crude was the warning system. Warnings were sent on a teletype machine at 80 characters per minute. On the day of the Super Outbreak, the warning system got jammed in some places, and warnings were delayed.
Since that time radar technology has improved dramatically, as have the warning systems. Most National Weather Service offices were having Doppler radar installed by the early 1990s. That gives meteorologists an indication of wind speed and rotations, as well as precipitation and intensity.
Audio titled GREG FORBES INTERVIEW ON THE SUPER OUTBREAK by 93WIBC
Some serious improvement
“We now have radars where we can not only detect rotation in a thunderstorm, but we can detect if there’s debris in a thunderstorm,” said WISH TV Chief Meteorologist Ashley Brown.
In a recent tornado, the Weather Service was able to give people better warning, knowing it was on the ground, said WISH Meteorologist Tara Hastings.
“The radar detected that debris was being lofted into the atmosphere. And we could tell that on radar with our new technology, with dual polarization radar,” she said.
You’ll often hear that referred to as a “debris ball”.
You may now get a warning anywhere from 15 to 30 minutes in advance, and you’ll get it on your cell phone, TV, radio, and NOAA weather radio, which was in its infancy in the 1974 Super Outbreak.
PHOTOS: Chris Davis/Emmis
