Into the Eye Of Ivan

THE BIG TURBOPROP LUMBERS DOWN a runway at MacDill Air Force Base, rises awkwardly into the air and heads northwest from Tampa Bay over the Gulf of Mexico. For a couple of hours, it glides through an aerial fairyland, maneuvering around sun-struck clouds that resemble turreted castles. "This isn't so bad," I say to my seatmate, Miami-based meteorologist Joe Cione, who looks at me and laughs. It's about then that I realize the pilot has executed a sweeping U-turn and pointed the plane's nose in Hurricane Ivan's direction.

Soon sheets of rain whip against the plane's windows, dissolving the reassuring sight of the wings. On the radar screen in front of my seat, the red of the eyewall--the circle of turbulent storms that surrounds a hurricane's eye--grows thicker and more menacing. "The red fingers of death," pilot Mike Silah jokes grimly, and as if on cue, the plane--a Lockheed WP-3D Orion operated by the National Oceanic and Atmospheric Administration (NOAA)--starts to pitch, roll and yaw, a small boat at the mercy of giant, invisible waves. I tighten the straps of my shoulder harness as the plane shakes violently. My seat drops out from under me, and for a moment, I experience the sickening feeling of free fall.

More than 40 people are thought to have died during Ivan's terrifying assault on the U.S., and many more might have died had people not taken the warnings issued by forecasters so seriously. For this, says Max Mayfield, director of the National Hurricane Center, part of the credit goes to aerial reconnaissance and surveillance missions similar to the one I'm on. The reams of data collected by each flight--"enough to choke a horse on," is how Mayfield puts it--have increased the credibility of hurricane landfall projections, and that, in turn, has prompted more people to evacuate to higher ground. Last week, for example, hundreds of thousands fled New Orleans, removing themselves from the threat of a storm surge in Lake Pontchartrain that could have flooded a city that lies largely below sea level.

The plane I'm riding in is itself a flying data-collecting instrument, with an air- sampling rod protruding from its nose and three radar units fastened to its nose, belly and tail. In addition, it has a pipe in the fuselage for launching sensor-loaded canisters known as dropwindsondes, sleek probes that take continuous readings of wind speeds, temperature, pressure and humidity as they parachute down. By combining the data obtained by multiple dropwindsondes, computer models can recon- struct the environment both inside and outside a hurricane, identifying conditions that feed or sap its strength or steer it in a particular direction. As a result, five-day hurricane-track forecasts are as accurate today as three-day forecasts were 15 years ago.