Unsettled Skies/Fleeing Floyd; Weather; Scientific American Presents; by Reed; 6 Page(s)

Last September Hurricane Floyd became one of the largest tropical cyclones to form over the Atlantic Ocean. As it threatened to incapacitate several major cities along the southeastern coast of the U.S., the nation's civil defense system snapped into gear. Sirens howled, schools and courthouses closed, and navy ships headed to sea. Along barrier islands, soldiers darted among houses instructing residents to clear out, while the National Aeronautics and Space Administration battened down its shuttles.

As the 600-mile-wide storm bore down on Florida with winds of 155 miles per hour--just one mile per hour below the threshold of the fiercest, Category 5, storms-the specter of its potency chilled coastal residents and alarmed local emergency managers. "Floyd had the potential to be the worst hurricane to ever strike the East Coast," says James Lee Witt, director of the Federal Emergency Management Agency (FEMA) and a cabinet adviser to President Bill Clinton on natural disasters. "This is the first time we have ever had an evacuation that involved so many states at one time. It was my worst fear."