Nick Elms isn't much interested in blue skies. Warm breezes leave him cold. But a blast of thunderstorms like the ones that ripped through the metro recently? He's there.

Elms, a volunteer severe-weather spotter, spent seven hours out in the meteorological melee, and his reports to the National Weather Service helped Twin Cities residents take the measure of the storm that hit Aug. 13: Golf-ball-sized hail. Winds at 62 mph. Flooding. Blowing dust. Other points of interest included three straight minutes of zero visibility and mud coating one side of his vehicle entirely.

That's what folks in the weather business call the "ground truth" -- specific storm information that even the most sophisticated technology can't see. In fact, when it comes to the mayhem that can break out between the clouds and the ground, spotters like Elms, meteorologists say, are often better than radar.

Last year, said National Weather Service meteorologist Todd Kraus, sightings from Skywarn spotters provided the trigger for a warning about a tornado that ultimately scraped across 30 miles of Nicollet and Le Sueur counties, killing one man.

"Only a spotter can see a tornado," said John Wetter, Skywarn operations coordinator at the National Weather Service office in Chanhassen.

Don't call them 'chasers'

Elms is director of West Metro Skywarn, a network of amateur radio-certified volunteer spotters that's one of hundreds of similar groups across the country. Unlike the thousands of daily temperature and precipitation observers across the countryside, Skywarn volunteers respond only in threatening weather. The National Weather Service provides training for new and regular spotters in weather identification, but the all-volunteer Skywarn organization, operating in all 50 states, is locally organized and self-activating.

Wetter said the network that feeds reports to the Chanhassen office of the National Weather Service, which issues forecasts and warnings for a 51-county area, is the most active in the country, with more than 3,000 trained spotters.

That level of involvement, Wetter said, is due to a regional culture that's "hypersensitive to weather," Internet- and amateur radio-savvy, and always ready to volunteer for community causes. "What it takes is a drive to serve your community," said Elms, 27, who's been a trained spotter since he was 18.

Many spotters say it's that sense of civic duty that distinguishes spotters from storm chasers, the more notorious band of weather watchers who often drive hundreds of miles in search of severe weather, often to shoot video or photos they can sell. Indeed, some chasers work on contracts for television stations. Chasers' photos are the foundation of Skywarn spotter training, but while all chasers are spotters, Elms noted, not all spotters are chasers.

At a recent Skywarn training session in Owatonna, it was clear that few of the more than 50 people who turned out were out to re-enact "Twister."

Mike Kadrie, who said he had come to the training with a men's group from his church, said he was motivated by the community-service idea, and also because storm-spotting was something he and his teenage son could do together.

Code name: Hookecho

For Elms, storm-spotting was a matter of confronting a demon. When he was 5 years old, a tornado that ripped through his family's St. Anthony neighborhood killed a kindergarten classmate of his.

For years afterward, he feared summer storms, until he decided to study them. He soon became a storm spotter.

"The sound of a siren used to be very, very scary to me. But now I'm actually part of the process that sounds the sirens and alerts my neighbors to what's coming," Elms said.

Today Elms devotes about 200 hours a year not only to spotting but also to training and talking to community groups about severe weather. His e-mail address name is "hookecho," the radar image that suggests a tornado.

Elms said the basic layout for a Skywarn spotter is simple: completion of a four-hour training session, a $100 handheld ham radio and a $12 operator's license. But Elms takes it to quite a different level.