Eastern states are bracing for the season's first hurricane as Irene tumbles through the Caribbean on a path toward South Carolina. It would be the first hurricane to strike the United States since 2008.

After grazing Puerto Rico on Monday and the island of Hispaniola, home to Haiti and the Dominican Republic, yesterday, Irene's core is curving north toward the Bahamas. Cyclone-strength winds span 200 miles from the storm's center, which is expected to strengthen to a Category 3 hurricane today over warmer water. Wind speeds could accelerate to more than 110 mph.

The National Hurricane Center forecasts that Irene could expand early Friday as it leaves the Bahamas, skirting to the east of Florida and bearing down on the Carolinas by early Saturday morning.

"We're going to have a very large tropical cyclone move up the Eastern Seaboard over the next five to seven days," Bill Read, the hurricane center's director, told reporters yesterday. "The impacts could be widespread, depending exactly on where the center of the storm goes. We see no reason for it not to be a major hurricane."

High surf and squalls could hit the Carolina coastlines ahead of the storm's center on Friday. Whipping winds could down trees and power lines, while rising sea surges and heavy rain could cause flooding in coastal communities that have grappled with subsidence and rising tides for decades.

The size and trajectory of Irene reminded Craig Fugate, administrator of the Federal Emergency Management Agency, of Hurricane Floyd, which shadowed Florida in September 1999 before ramming into North Carolina with a powerful surge.

Northern tract threatens wind and flooding

Seas swelled 10 feet and heavy rain, up to 20 inches in North Carolina and Virginia, flooded cities and roads for days. Floyd lumbered all the way up to Maine, dropping 4 to 12 inches of rain along the East Coast.

"People think hurricanes are a Southern thing," Fugate told reporters yesterday. "I would say the Northeast and mid-Atlantic U.S. coastal communities need to be taking the track of Irene very seriously."

Irene comes at the onset of the most severe stretch of hurricane season. The National Oceanic and Atmospheric Administration's Climate Prediction Center forecasts that the next two months could see a startling number -- between six and 10 -- of hurricanes. Between three and six of those could be at least Category 3 storms with winds exceeding 111 miles an hour.

Irene could also add misery to a year of devastating natural catastrophes. The first six months of 2011 set a new record for thunderstorm losses, accounting for 593 fatalities and $16.4 billion in insured losses. Major Mississippi flooding also tortured the Midwest and South this year.

Those climbing losses are making insurance companies rethink their approach to weather-related cataclysms. With thunderstorm losses now five times as much as they were in 1980, insurers are charging more and picking their coverage areas more carefully.

And now, Irene appears to be ending a three-year hurricane-free zone, a rare recess in a 20-year period of active landfall storms. Those punishing hurricanes contributed greatly to the $400 billion in catastrophe insurance claims since 1989, according to Robert Hartwig, president and chief economist of the Insurance Information Institute.

One thing seems certain: Those damages will continue to grow.

"The combination of population growth in coastal areas and a period of more frequent and severe storms increases the likelihood of even more catastrophic damage in the future," Hartwig said in a statement.