Archive for Wednesday, June 2, 2004

Bolts from the blue’ pose unexpected dangers

June 2, 2004

Lightning can strike from a sunshiny sky, as well as up to an hour after a storm has passed.

In a lightning storm, some rain shelters can be worse than having no protection at all.

And, not heeding those facts kills the great majority of lightning victims every year, according to Mary Knapp, state climatologist for Kansas.

"One of the most dangerous types of lightning is what folklore calls a 'bolt from the blue.' It's lightning that comes out of the side of a thunderstorm and travels away from the clouds -- often in clear air -- before angling down and striking the ground. It's been known to strike as far as 25 miles away from the storm," said Knapp, who heads the Kansas Weather Data Library, housed with Kansas State University Research and Extension in Manhattan. "The danger comes from the unexpected nature of the event."

Such bolts can strike while a storm is still a darkening smudge on the horizon. They can strike when a storm seems to be long gone.

"No one knows how far a bolt from the blue can actually travel," the climatologist said. "But you can assume that if a storm is nearby, you're at risk. If you can hear thunder, you're in danger -- no matter what the sky looks like overhead. You should be seeking shelter."

Knapp isn't surprised that most lightning deaths today occur while people are involved in outdoor recreation. The decision to call a game or end a jog can be difficult when the sky is clear overhead.

Rain shelters in recreation areas often are open on the sides, so they provide little lightning protection. This includes baseball dugouts, gazebos and bandstands, golf carts, picnic and dock shelters, bleachers and trees.

In fact, rain shelters can actually attract lightning if they're isolated, the tallest thing in the area, attached to a flag or light pole, equipped with electric or phone lines, or roofed with metal, Knapp said. Metal boats and any boat that's on the water are equally dangerous.

"In almost every case, large enclosed structures are safer than small or open structures," Knapp said. "But enclosed metal vehicles -- a school bus or car with the windows rolled up -- can provide good protection so long as you don't touch anything metal. That may mean curling up on the seat."

Commenting has been disabled for this item.