Hurricane Omar

Hurricane Omar strengthened into a major Category 3 storm as it raced toward Puerto Rico and the small islands of the northeastern Caribbean, threatening to bring torrential rains that could trigger dangerous floods and mudslides on Thursday.

The 15th tropical cyclone of a busy Atlantic hurricane season, Omar formed north of the Dutch island of Curacao on Tuesday, briefly disrupted oil operations in Venezuela and shut down processing units at a refinery in the U.S. Virgin Islands.

Omar was a Category 3 storm on the five-step Saffir-Simpson scale of hurricane intensity, with sustained winds of near 120 miles per hour (195 km per hour) as it passed between the Virgin Islands and the northern Leeward Islands, the U.S. National Hurricane Center said.

Omar was moving northeast near 20 mph (32 kph) and was expected to continue in that direction for the next couple of days. “On the forecast track, the center of Omar will pass just east of the Virgin Islands in the next few hours and near the northern Leeward Islands early Thursday morning,” the Miami-based center said.

In the U.S. territory of Puerto Rico, home to about 4 million people, schools, government offices and most businesses shut down. The seaside Capitol building was empty by early afternoon and a usually bustling shopping center was secured with hurricane shutters.

Residents flocked to supermarkets to stock up on drinking water, canned goods and other supplies.

“I’m not too worried, but I went out and bought water, candles and gas,” San Juan resident Kevin Mead, 35, said. “I paid with my bank card. I’m keeping my cash.”

Local National Weather Service director Israel Matos said there were fears the storm would affect the same areas hardest hit by heavy rains three weeks ago, when 30 inches (76 cm) of rain caused severe flooding.

“The ground is saturated, which increases the possibility of flooding and mudslides,” he said.

On Vieques, an island smacked by hurricanes Hugo in 1989 and Georges in 1998, residents rushed to board up houses and fill their cars with gasoline.

By 1 a.m. EDT/0500 GMT, Omar’s eye was about 25 miles (45 km) east-northeast of St. Croix, the hurricane center said.

On its current track the storm would head into the open Atlantic after passing through the Leeward Islands, posing no threat to the United States.

TROPICAL DOWNPOUR

Omar brought heavy rains to the Netherlands Antilles islands, and parts of Venezuela and Colombia, and could douse Puerto Rico and the northern Leeward Islands with up to 20 inches (51 cm) of rain, the hurricane center said.

Storm alerts were posted a wide area of the northern Caribbean from Puerto Rico to Guadeloupe.

The storm briefly prevented Venezuela from loading tankers with crude oil and knocked out power at the OPEC nation’s 200,000 barrel-per-day Puerto La Cruz refinery.

Processing units at the 500,000 barrel-per-day Hovensa refinery on St. Croix in the U.S. Virgin Islands were being shut down ahead of Omar’s arrival, Hess Corp said.

Hovensa is a large supplier of gasoline and heating oil to U.S. East Coast markets.

Separately, a tropical depression had moved inland over Honduras on Wednesday, but did not strengthen enough to become Tropical Storm Paloma.

The 2008 hurricane season, which officially ends on Nov. 30, has been active. An average season spawns 10 storms, of which six become hurricanes.

This year, Hurricane Gustav hit near New Orleans, the city devastated by Hurricane Katrina in 2005, and Hurricane Ike hit Houston. Both threatened oil rigs off the U.S. Gulf Coast, which supply a quarter of U.S. domestic oil.

In Haiti, more than 800 people were killed in flooding caused by Fay, Gustav, Hanna and Ike, while Cuba suffered $5 billion in damage after being raked by Gustav and Ike.