FORT WORTH, Texas — Everyone is complaining about the relentless drought, but a handful of Texas groups are trying to do something about it by wringing a little more rain from the few clouds in the sky.

Meteorologists working on seven cloud-seeding projects that stretch from the Panhandle to the Rio Grande Valley monitor radar from April through September to identify towering cumulonimbus clouds that can be "nudged" into producing more rain.

"We give clouds a shot of adrenaline," said Todd Flanagan, a meteorologist for the South Texas Weather Modification Association in Pleasanton.

Experts say long-term results show that cloud seeding can produce 10 to 15 percent more rain than falls naturally.

"We're not sitting on our hands; we're trying," said George Bomar, of the Department of Licensing and Regulation. The agency permits the projects, which cover nearly 31 million acres, or almost one-fifth of the state.

The programs are all sponsored by groundwater districts, he said, noting that they started with the help of state funding that dried up in 2002.

Research shows that seeding projects produce a "couple of hundred thousand acre-feet of rainfall annually," said Bomar, a meteorologist and author of the book Texas Weather.

But in a record one-year dry spell, even clouds have been scarce.

"This year, the shortage in cloud resources is a real problem. It's the worst year in the 12 years I've been here," said Archie Ruiz, an instructor at Texas Tech University.

"The drought is limiting things. Normally you could seed 100 to 120 clouds in San Angelo. This year, up until June 30, there were less than 20 clouds," Ruiz said.

The programs use aircraft with silver iodide flares affixed to their wings. The flares are ignited into the updraft of developing clouds.

Meteorologists target clouds with supercooled cores above 17,000 feet in altitude, Bomar said.

Pilots ignite the flares at around 8,000 feet, and the aerosol travels up into the cloud tower. Water droplets then cling to the silver iodide, which has a molecular structure similar to ice's.

After 15 to 20 minutes, the ice particles melt into rain as they fall through warmer air in the cloud.

With small clouds, pilots will fire six to 10 flares. On a huge cloud, pilots will make multiple passes over several hours and use up to 50 flares, Rhodes said.

A flare with 40 grams of silver iodide costs $50 to $60, Ruiz said, noting that the biggest expense is operating the aircraft.

"From the point of view of cost to benefit, it is really cheap. It's amazing how effective it is," he said.

The Panhandle cloud-seeding project costs about $200,000 a year, or 4 to 5 cents per acre, Williams said.

Jennifer Puryear, the Panhandle district's meteorologist, said cloud seeding "definitely works."

"It's all about timing. You have to be there at the right time when the cell is beginning to develop," she said.

"If you were to see the radar image, you would be a believer instantly. You can compare it to stuff that isn't being worked and you can see the difference."

Cloud seeding is not without controversy.

"We have some people who say we are fooling with Mother Nature," Williams said.

Some critics believe seeding can take the rain from areas farther along a cloud's path or cause destructive flooding.

A bitter fight over cloud seeding forced the shutdown of a Lubbock-area program in 2002, said Jim Conkwright, general manager of the High Plains Underground Water Conservation District.

"We had a number of people who felt we were discouraging rain by breaking up clouds," he said.

"There's definitely two camps about cloud seeding, and they're 180 degrees apart," Conkwright said.

"It was a very heated fight. There were lives threatened. It got very hostile," he said. "It just wasn't worth that sort of thing, so we gave it up."

Still, most states west of the Mississippi River are involved in cloud seeding, Bomar said, noting that in the Rockies, the work is done in the winter to increase snowpack.

The drought of 1996-97 spurred the Texas Legislature to initially fund cloud-seeding programs, and at one time there were 12 projects.

When a budget crunch in 2002 killed the matching funds, the programs that had used the money to fund infrastructure such as aircraft and radar survived. The five that had contracted for cloud-seeding services died, Bomar said.

As the current drought has intensified, Bomar is fielding more inquiries about cloud seeding.

"Drought always increases interest. But I'm the first to warn folks that during a drought, you have a limited return," he said.

"It isn't a quick fix."