STORM2K

FARGO, N.D. - Scientists are piecing together a statistical profile of a devastating tornado that swept through this city nearly a half century ago.


The National Weather Service in Grand Forks is gathering every bit of data it can find on the twister that struck on June 20, 1957, leaving 13 people dead and more than 1,300 homes damaged or destroyed.

"We are recreating some of the meteorological variables in the atmosphere for that day," meteorologist David Kellenbenz said. "We're looking at things like wind-shear, what makes a thunderstorm really grow and get very large.

"This was a tremendously large super cell thunderstorm," he said. "It actually lasted for about six hours, and it was tornadic for four hours."

The tornado was one of five spawned from a thunderstorm that left a trail of damage 70 miles long from Buffalo to Dale, Minn. Debris from the Fargo tornado was found 54 miles away.

University of Chicago researcher T. Theodore Fujita spent more than a year studying the tornado. The work helped him come up with what is known as the Fujita Scale in 1971, which has been used ever since to rate tornado intensity.

The Fargo tornado topped the scale at F5.

The Weather Service is reviewing records and compiling details on what the weather was like that evening as a way to mark next summer's 50th anniversary of the disaster.

"As much as we can, we are recreating the atmosphere from 1957 in hopes of being ready for the potential of another one," Kellenbenz said.

In addition to gathering scientific data, the Weather Service is asking the public for stories and recollections from that night.

Jayne Haugen Hanson was 6 years old when the tornado roared into her neighborhood. She now lives near Walker, Minn., and has told the story to her own children many times.

"I am 54 years old now and summer storms still remind me of that night," she said.

While it is difficult to gauge wind speeds in a tornado, the Fargo twister is believed to have packed 275 mph winds, Kellenbenz said.

F5 tornadoes are relatively rare, he said. The last one recorded in the United States struck Oklahoma City in 1999.

Kellenbenz said he hopes the study he is working on does more than commemorate the anniversary of the Fargo tornado.

"We want to get the word out that these large F5s, the most destructive tornadoes, can happen in our back yard," he said.