Originally created 06/28/01

Summer ushers in storms



Downed trees, puddled water and spotty windshields are commonplace in Augusta because of recent, often severe, afternoon thunderstorms.

But the storms are to be expected during the summer months, said meteorologist Al Moore of the National Weather Center in Columbia.

What's happening is that the three ingredients required for a thunderstorm are most often present during the months when the weather is warm. This year, there seem to be more thunderstorms than usual, Mr. Moore said.

And, he said, more thunderstorms are on their way, at least through the weekend.

"The pattern recently is really the result of a combination of strong heat from the sun, plus pockets of energy in the upper atmosphere circulating in the area," Mr. Moore said.

The sun's rays heat Earth during the day, creating rising warm air, one ingredient that is more prevalent during summer.

Moisture, which forms clouds and rain, is another ingredient.

The third ingredient, lift, helps move the air upward, Mr. Moore said.

Dr. Martin Uman, the chairman of the Electrical and Computer Engineering Department at the University of Florida, researches lightning at the university's lightning lab at Camp Blanding.

Dr. Uman said the rising moist, hot air reaches Earth's upper atmosphere, where there is ice in the clouds.

"The interaction makes electrical interference, and that's how you get thunder and lightning," Dr. Uman said.

Strong winds are generated when the hot air that traveled upward moves back down and spreads out. The farther it travels downward, the stronger the winds.

Strong winds, with gusts of 55 mph, were the problem Friday when a severe thunderstorm hit Augusta, downing trees and scattering debris.

Sam Smith, operations manager and horticulturist for the Augusta-Richmond County Trees and Landscape Department, said the winds tore a number of hackberry trees - some 80 feet tall - out of the ground along Riverwalk Augusta. He said when the trees' leaves become saturated with rain, the tops are "like a big sail" and the winds pull the trees over.

Mr. Smith, who said there isn't a damage estimate on the trees yet, said he wants to complete cleanup from Friday's storm by week's end.

Riverwalk is the priority, he said.

"We're hoping to have the riverwalk cleaned up by July Fourth," he said..

Reach Teresa Wood at (706) 823-3765 or Amy Swann at 823-3338.

Storm facts

According to the National Weather Service, thunderstorms average about 15 miles in diameter and last about 30 minutes. About 16 million occur worldwide each year. For more information, check out www.nws.noaa.gov.