Into the Eye

As the Hurricane Hunter flew toward the fierce eye wall of Ivan on Tuesday afternoon, crew members snapped on their seat belts. "It's probably going to get a little bumpy here very shortly," said one of the pilots over the radio. Battered by 145mph winds, the plane dropped and heaved with stomach-churning force. Outside, clouds lost their contours, darkening into a menacing murk. Far below, the ocean occasionally came into view, its surface marbled with white streaks as the wind pulverized it into foam and mist. "Forty-foot waves down there," said Ed Walsh, a NASA scientist testing a new device that provides a topographical map of the ocean's surface. "Missing a swell of a lifetime," came the reply. Closer still to the eye, the plane tossed more aggressively, its four propellers droning implacably. "One hundred forty-plus knots," or 161mph, declared a crew member measuring wind speed. The plane became engulfed in mist.

Then the churning suddenly calmed. The clouds brightened and parted. A new topography bared itself, with distinct cloud formations arrayed in spectacular peaks and canyons. High above, patches of azure sky opened to the heavens. The Hurricane Hunter had entered the eye. Crew members stood up, walked around, shot pictures through the windows. The tranquility only lasted a few minutes, until the plane re-entered the opposing eye wall, succumbing once again to a steady beating. "Those are good hurricane conditions," said Jim McFadden, chief of the programs staff at the National Oceanic and Atmospheric Administration's (NOAA's) Aircraft Operations Center. The jovial response over the radio: "You mean bad hurricane conditions."

It was the beginning of another long day for the sleep-deprived crew, which has been working without pause during the past month of unremitting hurricanes. Its plane, a nearly 30-year-old WP-3D Orion nicknamed "Miss Piggy," is one of two (the other is "Kermit") Hurricane Hunters housed at MacDill Air Force Base in Tampa, Fla. Every hurricane season, from August to November, they are pressed into duty, along with the NOAA's Gulfstream jet (which gauges the currents that steer hurricanes) and Air Force C-130 planes. NOAA's pilots, engineers and scientists use high-tech equipment to take key measurements and transmit them to the National Hurricane Center in Miami. Without such data, forecasters would have to rely far more on guesswork to predict a hurricane's path and intensity. This season, the crews have been getting a workout. "It's been so crazy," says Michael Black, a research meteorologist for NOAA. "We're giving everything we've got to this storm."

The Hurricane Hunter was specially designed for just this sort of duty. It bristles with radars and other gizmos. A Doppler radar renders a three-dimensional view of a hurricane by slicing it every six seconds the way a CAT scan might. That provides forecasters with a structure of a storm's rainfall and winds. A device called a step frequency microwave radiometer, or "smurf," measures wind speeds on the surface of the ocean. Contraptions called dropsondes--foot-and-a-half long tubes--are ejected from the plane in particular sections of a hurricane. As they fall, slowed by a parachute, they transmit data on air pressure, temperature, humidity, wind speed and wind direction every half-second until they're swallowed by the sea. The result: a real-time portrait of a hurricane's unique character, the ferocity of its eye walls, the breadth of its hurricane-force winds. "No two hurricanes are alike," says flight director Tom Shepherd. "They're like fingerprints."

For its part, Ivan "is really holding its own," said meteorologist Black aboard the Hurricane Hunter on Tuesday night. "It's a mature storm now that has reached a relaxed state," added McFadden, the chief of programs staff. "What makes [Ivan] spectacular is its size and wind speed" as it bears down on the Gulf Coast. All week, it has strengthened and waned, vacillating between Category 4 and Category 5, the most powerful class of hurricane, with winds greater than 155mph. The barometric pressure readings were rising on Tuesday, suggesting that the storm was weakening. But that could change: a warm eddy lurked in the gulf that could fuel Ivan to a boil once again. "A hurricane is a heat engine," Black explained, transferring energy from the ocean into the upper atmosphere, where it powers the tempest's churning.

Ivan's eye has also been erratic. Rather than twisting around one starkly defined tight eye, it has numerous eyes, arrayed in concentric circles, one collapsing as another spirals out of the muck. The result: a so-called "dirty eye," one that's indistinct and cluttered with clouds. While that's preferable for the unfortunate souls in Ivan's path (a messy 40-mile-wide eye isn't as fearsome as a well-defined vortex 10 miles across), it's less beautiful to behold. The crew aboard Miss Piggy lamented the lack of a "stadium" effect--a dramatic view from inside the eye of soaring and sloping walls framing a gleaming blue sky.

Riding aboard the Hurricane Hunter can at times be harrowing. McFadden recalls the time in 1989 when he ventured into Hurricane Hugo and lost an engine as the plane hit an unexpectedly violent eye wall. Equipment ricocheted off the walls of the fuselage and a loosened life raft nearly squashed McFadden. The crew ended up dumping its excess fuel and climbing its way out of the eye in a tight spiral. On Tuesday's flight, the ride wasn't nearly as terrifying, but it was certainly turbulent. At one point, when the plane took an unexpected dip, this reporter, who was standing, levitated briefly, while clinging onto a ceiling rail.

Back on secure ground, the crew members celebrated a momentous occasion: McFadden, alone among his peers, had penetrated his 500th hurricane on the just-completed flight. His crewmates presented him with a gold patch and regaled him over champagne and beer. But the partying didn't last long. There was another mission to fly the following evening--the last chance to size up Ivan before it hit land. And beyond Ivan, another tropical storm lurked in the Caribbean, gathering force and threatening untold destruction.

Into the Eye | News