Читать книгу The Proving Ground: The Inside Story of the 1998 Sydney to Hobart Boat Race - Bruce Knecht - Страница 10

THE HOBART IS far from the sailing world’s longest blue-water contest, but it has a reputation for being one of the most treacherous. Bass Strait, the 140-mile-wide stretch of water that separates Australia’s mainland from Tasmania, is one of the world’s most turbulent bodies of water. The two landmasses were once attached, and today the gap is much shallower than the oceans to the east and west. When waves that have been building for hundreds of miles pass over its shallow bottom, they tend to break like surf on the beach.

Many yachtsmen believe that every seventh Hobart is subject to a special curse. Particularly severe storms savaged the fleet in 1956, 1963, 1970, 1977, and 1984. In 1977, fifty-nine yachts dropped out of the race. In 1984, 104 out of 150 boats retired in gale-force winds. The pattern appeared to end in 1991—or maybe was just delayed until 1993, when only thirty-eight out of 110 starters made it to Hobart. Regardless, some of the sailors remembered that the original pattern would make 1998 one of the bad years.

But the potential for a dangerous storm wouldn’t cause CYC officials to consider postponing the race. Like yacht clubs everywhere, it abides by the five fundamental rules set by the International Sailing Federation. Rule number four declares: “A boat is solely responsible for deciding whether to start or to continue racing.”

Brett Gage, a senior forecaster at the Bureau of Meteorology, arrived at his sixteenth-floor office in downtown Sydney at four o’clock on Saturday morning, nine hours before the start of the race. As in previous years, the bureau had agreed to provide special weather forecasts to the Cruising Yacht Club, and Gage had a lot to do: he had to decide on the prerace forecast, assemble a collection of weather data into information packages for each yacht, and then rush to the CYC so he could individually brief as many skippers and navigators as possible.

His biggest complication was the weather itself: nobody could agree on what it would be. At a preliminary briefing at the CYC on Christmas Eve, Kenn Batt, another forecaster from the bureau, had described several possible scenarios but said he wasn’t sure which one would actually develop. Batt and Gage based their forecasts on three global, computer-generated weather-forecasting models as well as an Australia-based model that projected only local conditions. The U.S.-based global model, which some Australian forecasters thought tended to overstate the severity of storms, was predicting an intense low-pressure system, one that could produce hurricane-force winds. The two other models, one produced by a weather center in continental Europe and the other by a center in Britain, were forecasting a much less dangerous storm. During his Christmas Eve briefing, Batt had said a low-pressure system might develop south of Australia and move north at the same time the fleet headed south or that it could fizzle out on Christmas Day. “All the computer models are saying different things,” Batt had said, provoking an outbreak of laughter. “But a strong low could be in the cards, and it could kick up strong winds and a pretty big sea.”

Predicting weather in any one place requires an evaluation of the patterns for the rest of the world. The three main forecasting models are based on millions of observation points spread around the globe. For each of more than 100,000 grid points, data on wind speed, barometric pressure, temperature, and humidity are gathered from weather stations and balloons as well as from drifting buoys and are combined with estimates for twenty-nine levels of the atmosphere for every grid point, creating more than 3 million data points. Information for every one of them, plus additional data from planes and satellites, is fed into super-computers for each of the models, which make more than 20 million calculations per second for more than an hour, to produce global pictures of the shifting temperatures, pressure, and high-altitude jet streams that create weather.

The models Batt was examining predicted very different levels of barometric pressure. The discrepancies were crucial: variations of pressure are what produce wind. At any given moment, the world’s atmosphere has more than one hundred regions of low pressure, and air from everywhere else is rushing toward them. The lower the pressure, the swifter the wind. In Southern latitudes, when the air approaches the center of the low, because of the earth’s rotation, the wind circles in a clockwise pattern (called the Coriolis effect), creating the kind of swirling clouds familiar from satellite images. If the force is powerful enough, it develops into a “tropical cyclone”—which is the same thing as a “hurricane” in America or a “typhoon” in northern Asia.

Early Saturday morning, as Gage sipped his first cup of coffee and scanned the latest satellite photographs and computer outputs, it was clear that a low was still forming, but the models continued to disagree about its intensity. The information packages he began to put together included predictions for barometric pressure as well as for wave heights and tidal changes, a satellite photograph showing that there were hardly any clouds over Australia, and a “strong wind warning,” indicating that twenty-five-to-thirty-three-knot winds should be expected. (A knot is one nautical mile, 1.15 statute miles, per hour.) But Gage knew it could be much worse, and he was afraid the race would start before he could make a definitive judgment. At 7:30 A.M. he ran into another problem: the bureau’s high-speed photocopying machine broke down, forcing him to finish running off the sheets of information for the packages at the CYC.

Kenn Batt, who was helping assemble the packages and who planned to conduct some of the briefings at the CYC, remained at the bureau, hoping to obtain updated information. Batt, who was forty-eight, had been a member of the bureau for twenty-five years but had begun forecasting long before that. As a teenager growing up in Hobart, he began producing forecasts for the Royal Yacht Club of Tasmania, which he posted on a bulletin board every weekend. He knew weather and he knew sailing: Batt came from a family that had been racing for four generations, and he had sailed in seven Hobarts.

Just before 9:00 A.M. Batt received the latest output from the European and British models. They predicted lower pressure than they had before, though still not as low as the American model. Calling Gage, Batt said, “Don’t hand out the packages. We’re upgrading the forecast to a gale warning,” which indicated expected winds of thirty-four to forty-seven knots. “We’ll fax the warning through in a couple of minutes so you can incorporate it into the package.”

By the time Batt arrived at the CYC, Gage had set up a table and hung weather maps from a nearby wall. During the next three hours, representatives from eighty-six yachts picked up weather packages. Some of the yachtsmen just took them and left. Others asked lots of questions. “You’ll have a nice run this afternoon,” Batt told one of them, “but there’s a front building down south. We’re not sure which way it’s going, but it could develop and become really nasty. We could have a 1993 situation.”