Active hurricane season forecast, but who listens?
A recent poll finds that fewer than half of coastal residents are prepared.
Seaside residents from New England to Texas can't say they haven't been alerted.Skip to next paragraph
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Four groups, including the US government, are calling for a hurricane season far more active than average - although no group currently expects as many storms as last year's record-setting 27. At least two groups are attempting to estimate the likelihood that specific segments of the US coastline will feel the brunt of some of these storms - a far more difficult prediction to make.
Yet for all the time and effort researchers have put into developing these outlooks, some evidence suggests that they might do just as well by telling coastal residents to be prepared no matter where they live. Too often, those warnings go unheeded, a recent poll suggests.
"It takes just one hurricane over your house to make for a bad year," says Max Mayfield, director of the National Hurricane Center. He and his colleagues are placing an extremely high emphasis on individual preparedness, which means being able to take care of one's family unassisted for at least 72 hours.
Still, efforts to warn residents, emergency planners, and industry are worth it, maintains Gerald Bell, who heads up the effort at the National Weather Service's Climate Prediction Center. Hurricanes remain the country's most costly natural hazard year in and year out. "If you're going to have an active season, people need to know that," he says. These are highly confident forecasts."
At a briefing in Miami Monday, the National Oceanic and Atmospheric Administration (NOAA) spelled out its initial forecast for the season, which will be updated in August, on the eve of the season's peak period. It expects 13 to 16 named tropical storms this season, with eight to 10 of those becoming hurricanes. Of those hurricanes, four to six will be intense hurricanes registering Category 3 or above.
That's on par with the forecast from Tropical Storm Risk, based in Britain, which is calling for 14.6 tropical storms during the Atlantic season. Of those, it expects 7.9 to become hurricanes and 3.6 to reach at least Category 3. In April, the hurricane forecast group at Colorado State University estimated that the season would yield 17 tropical storms, leading to nine hurricanes, five of them intense.
Explanations for the high level of storm activity - particularly what some researchers see as an increase in the proportion of strong storms - are mired in a controversy over whether the increased activity in the Atlantic is the result of natural climate variations or global warming.
In NOAA's forecasts, for example, a feature dubbed the Atlantic multidecadal oscillation plays a key role. This is thought to be manifest as a 20- to 40-year (or by some accounts 50- to 80-year) swing in ocean and atmospheric conditions in the North Atlantic. Currently, the North Atlantic is said to be in a warm phase. Warm ocean temperatures fuel hurricanes. Thus, its advocates hold, the Atlantic multidecadal oscillation currently is driving any increased punch.
Others, however, including researchers at the Massachusetts Institute of Technology and Georgia Tech, hold that the increased proportion of strong storms could well be driven by global warming's heating effect on the oceans in the tropical Atlantic, where hurricanes form.
Yet for all the improvements that have been made in seasonal forecasts, they can be unintentionally misleading, notes Kerry Emanuel, a hurricane researcher at MIT. He points to the 1992 season, which was forecast as a season with lower-than- normal activity. Then hurricane Andrew slammed into south Florida.
This has led some forecasters, such as the group at Colorado State and AccuWeather Inc., to attempt landfall forecasts. Comparing today's preseason climate patterns with those of past active years, AccuWeather expects that six tropical cyclones will hit US coasts. Of those, the company expects five to be hurricanes and three to arrive as major hurricanes. As the season progresses, the risk shifts from the Gulf Coast to the Eastern seaboard up through New England, the company holds. The Colorado State group sees a 79 percent likelihood that at least one hurricane will strike the Gulf Coast; the figure is 89 percent for Florida and the East Coast.
But if seasonal forecasting is in its infancy compared with storm-specific forecasts, landfall forecasts are hardly out of the delivery room.
Trying to develop meaningful landfall outlook this far in advance is difficult because storms are driven by local and regional conditions that occur on time scales too short to forecast this far in advance, Dr. Bell notes. "Different combinations of conditions can produce an active season," and those combinations can impose different effects on weather conditions over the eastern US and the western Atlantic that govern storm tracks."
It's not at all clear that coastal residents are paying that much attention. After more than 20 years of seasonal forecasts for Atlantic hurricanes from one group and nearly 10 years' worth from others, a recent survey suggests too many residents in hurricane-prone areas aren't taking the basic steps that emergency-management experts recommend. For example, fewer than half of Gulf and Atlantic coast residents have a family-response plan or a hurricane "survival kit," according to a poll of 1,100 Americans for the National Hurricane Survival Initiative. At least a third lack adequate insurance.
If residents don't always take heed, insurance companies do, notes Dave Unnewehr, an official with the American Insurance Association in Washington. These forecasts can play roles in individual company decisions about coverage in hurricane-prone areas as well as in how much reinsurance companies may want to buy to protect them against excessive losses.