Behind every picture there's a story. Two of the cloud stamp photos were taken by local photographers. Here's their story:

Dave Hoadley snapped this golden moment in northeast Kansas on June 6, 1971. He didn't just happen to be there; he was looking for a good storm. You see, storm-chasing is Hoadley's hobby. He has been doing it for 48 years -- he's even listed in the Guinness World Records Book for "longest experience as a storm-chaser"!

Each spring Hoadley studies the upper-air patterns. If a major storm is looming in the Midwest or Plains states, he packs his camera gear, hops in his car and heads out from his home in Falls Church. He drives 20,000 to 30,000 miles each year to experience "the beauty of nature in a wild, raw, uncontrolled form."

His description of his Kansas mammatus: "Awesome."

The ripples appeared over

H. Michael Mogil's house in Rockville one morning a few years ago. Mogil, a meteorologist and weather educator, says he "walked out the door, looked up and said, 'Wow!' " He rushed to take a picture, a photo he now considers "a piece of art."

From "art" to "stamp" took a bit longer, however.

Mogil and others had been trying to interest the U.S. Postal Service in weather stamps for about 15 years, seemingly without luck. Then he was asked to be on a panel helping postal officials find the best cloud pictures available. The final 15 were chosen from a pool of about 100.

Mogil says stamp collecting as a boy taught him about other people and places. He offers this advice to budding photographers: "I carry my camera around my neck wherever I go. I never know what photograph is going to say, 'Take me!' "

-- Marylou Tousignant