New urgency in efforts to forecast hurricanes

For two years running, no hurricane has made landfall along the US East and Gulf coasts. Historically, however, these coasts have never gone three years without a hurricane striking somewhere along their length, federal hurricane forecasters say.

The prospect that these regions are "due" a hurricane is adding urgency to projects designed to lengthen the lead time for warnings and develop an ability to forecast a storm's intensity more accurately.

It also is prompting the National Weather Service to boost its efforts to bring inland populations up to speed on the need to prepare for the effects of hurricanes that bring with them high winds, tornadoes, and torrential rains as they move over land, weaken, and break up.

"The public hasn't seen a land-falling hurricane in two seasons, and we know from previous experience that out of sight is out of mind," notes Max Mayfield, director of the National Oceanic and Atmospheric Administration's National Hurricane Center in Miami.

Federal forecasters say they expect from nine to 13 named storms in the Atlantic and Caribbean regions this season, which began June 1 and runs through Nov. 30. Of these, six to eight could become hurricanes, with two or three becoming "major" hurricanes – tropical cyclones with sustained winds exceeding 111 miles an hour. This forecast dovetails closely with that of William Gray, a Colorado State University researcher who pioneered seasonal hurricane forecasts.

Dr. Gray's team has worked recently to devise broad land-fall probabilities for the country's hurricane-prone coasts. Along the Gulf Coast, Gray's team holds that there is a 67 percent probability that a hurricane will strike land this season, while the East Coast through Florida stands a 73 percent probability of taking a hit from a hurricane. The team warns, however, that a lower likelihood shouldn't be used as a reason to skimp on preparedness.

Federal officials add that tropical storms – one notch below hurricanes – can pack a punch of their own. Last June, for example, tropical storm Allison struck Houston and lingered for five days, dropping nearly 37 inches of rain. By the time Allison had moved across the southeast and up the East Coast 12 days later, it had inflicted $5 billion in damage, while the death toll reached 41.

In an effort to give emergency managers more time to evacuate residents when a hurricane threatens, forecasters have developed an experimental, five-day landfall forecast that could become a staple if the results from a second year of tests this season prove "reasonable," says James Franklin, a hurricane specialist at the National Hurricane Center. Currently, he explains, the center issues these forecasts up 72 hours in advance.

Much of the impetus for the five-day forecast has come from the US Navy. When a hurricane threatens, the Navy must move ships and aircraft out of the storm's way. The current forecast barely gives the crews time to fire up their ships' boilers.

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