Officer Brad Scalio can't help it. The rookie D.C. cop admits he is addicted to thunderstorms.

At 27, Scalio left his 9-to-5 job as a meteorologist to fulfill a lifelong dream of becoming a police officer. But he remains obsessed with weather -- and it paid off the other night.

Thanks to a weather Web site he was using to track a thunderstorm, Scalio learned about a suspected bank robber from Nevada who allegedly had gone on the lam with his 8-year-old son. The boy, who is blind and a quadriplegic, was the focus of an Amber Alert, which was posted by the National Weather Service along with the latest storm activities.

Scalio nabbed the man Wednesday night after he spotted a car with Nevada license plates on Bladensburg Road NE, authorities said.

The boy, 8-year-old Kyle Brown, was reported missing Nov. 3, when his father, Daryl Neil Brown, left their tiny, sagebrush-filled town of Winnemucca, Nev., for Reno, where he robbed a bank without using a gun, police said.

"It was a note job," said Special Agent David Nanz, spokesman for the FBI office in Las Vegas. Authorities got pictures of the robber, triggering a federal warrant, he said.

Brown then took off across the country, police said. Authorities said that even though Brown is his son's primary caregiver, they issued the Amber Alert because they had information that Brown might be suicidal. The alert is an urgent appeal to police and the public for help finding a child.

The Amber Alert included a picture of Kyle, with his big brown eyes and slight smile. And there was information about his father's car, an old green Jeep with the Nevada license plate 623RWD.

That's where Scalio's weather obsession comes in.

Unless Amber Alerts are specifically targeted for the D.C. area, they are not part of city police officers' daily patrol briefings. But when Scalio, four months out of the police academy, is off duty from his job as a 5th District officer, he keeps track of weather Web sites.

He was following thunderstorms hitting West Virginia, and in the middle of the staccato recitation of wind speeds and pressure systems, he came upon the alert. Scalio used to help post the alerts himself when he was a meteorologist.

When he saw the license number on the Web site, his years of studying at Penn State kicked in, and he used a memorization trick. "I saw the last three letters, 'RWD,' so I automatically thought, 'That's a Jeep with rear-wheel drive,' to remember it," Scalio said.

The next night he was dispatched to a car accident on New York Avenue. On the way, he stopped behind a green Jeep. "I saw those letters, 'RWD.' And that Nevada license plate. I couldn't believe it. I had to double-check and call it in to make sure," he said.

He and other officers pulled the Jeep over. Brown stopped and was arrested without incident. Kyle was in the back, quiet and strapped to a car seat, Scalio said. He was taken to Children's Hospital for observation, and his mother is flying in from Winnemucca to pick him up today, police said.

As for Scalio, he's pleased his meteorological background helped him on the streets.

"I still miss the weather sometimes," he said. "But I've always wanted to be a police officer."

D.C. Officer Brad Scalio, left, with Officer Albert Miller. A bank robbery suspect was arrested after Scalio spotted a vehicle whose license was posted in an Amber Alert on a weather site.