Hurricane Felix became an extremely dangerous Category 5 storm on Sunday as it swept through the southern Caribbean on a path toward Central America and Mexico's Yucatan Peninsula, US forecasters said.
On a similar though more southerly track as last month's powerful Hurricane Dean, which killed 27 people, Felix's top sustained winds had increased to 165 miles per hour(270 kph) by 8 pm EDT, the US National Hurricane Center in Miami said.
That made the second hurricane of the 2007 Atlantic storm season, located about 390 miles southeast of the Jamaican capital, Kingston, a Category 5 storm on the five-step Saffir-Simpson scale, capable of causing catastrophic damage.
Forecasters at the hurricane center said Felix was strengthening at one of the fastest rates seen, as measured by the drop in its minimum internal pressure.
It was passing over a warm eddy of water in the central Caribbean, finding in it the fuel needed to rev up to a Category 5.
Hurricane Dean became a Category 5 storm in mid-August before slamming into the Yucatan, south of the tourist resort of Cancun.
US Gulf of Mexico oil and natural gas producers, who account for a third of the United States' crude production and 15 percent of its natural gas production, were monitoring Felix, but had not evacuated offshore workers so far because its forecast track did not appear to threaten them.
Category 5 hurricanes have been rare. Before the devastating 2005 hurricane season, only two years on record had seen more than one Category 5 hurricane.
The 2005 season experienced four, including Katrina, which devastated New Orleans, and Wilma, the strongest Atlantic storm ever seen. The increase in the number of top-ranked hurricanes has provided backing to research showing global warming may produce stronger tropical cyclones.
Despite its rapid strengthening, Felix was too far away to prove much of a threat to the Netherlands Antilles.
Dawn had broken on Curacao to reveal toppled trees and flooded streets but neither it nor its sister island Bonaire reported serious damage or casualties.
"The local population and visitors remained in their homes and hotels overnight. No calls were received on the emergency line set up in preparation for the storm," Bonaire Lt Gov Herbert Domacasse said in a statement.
In Curacao, unused to hurricanes because hurricanes normally track well to the north, supermarkets remained open late into the night to allow startled residents to stock up on emergency supplies.
The authorities opened shelters for people living in vulnerable areas, such as on the coastline, and the island's airport closed for several hours.
Hurricane watches in Aruba, Curacao and Bonaire were lifted but tropical storm watches were up for Jamaica and Grand Cayman, even though Felix was expected to keep well south as it moved west-northwest near 18 mph (30 kph).
The storm was expected to produce up to 4 inches over the Guajira Peninsula in northern Colombia.
The 2007 hurricane season, expected to be a busy one, is reaching its peak. Most storms hit from August 20 to mid-October, with September 10 marking the statistical height of the season.