UPDATE: The U.S. Geological Survey reports a magnitude 4.3 earthquake has rattled Hawaii's Big Island, as two hurricanes rumbled toward the islands.
The temblor struck on the north tip of the island, about 7 miles from Waimea at 6:24 a.m. local time.
Hurricane Iselle was on course to hit the Big Island Thursday night, and was being tailed by Hurricane Julio, which strengthened early Thursday into a Category 2 storm.
(NBC News) - Hawaii braced for its first direct hurricane hit in 22 years Thursday as Iselle headed toward the Big Island with a second storm on its tail.
Forecasters originally thought Iselle would weaken substantially before hitting the main island, but the fast-moving Category 1 hurricane would not have the chance to lose vigor before hitting Hilo — on the Big Island — on Thursday night, according to Weather.com.
Heavy rains totaling 5 to 8 inches, winds gusting up to 85 mph, and flooding were expected.
Waves could grow up to 28 feet due to Iselle, the National Weather Service warned. “It's a fairly potent hurricane by Hawaiian standards,” said Weather Channel meteorologist Kevin Roth.
Iselle was set to weaken to a tropical storm by the time it hit Honolulu at about 9 a.m. local time (3 p.m. ET) on Friday, but just 900 miles behind, Julio had strengthened to a Category 2 hurricane.
Roth said Julio was expected to weaken to a tropical storm before making landfall, but the storm's exact center would not be certain until later in the week.
Hawaii has been hit by hurricanes only three times since 1950, the last being deadly Iniki in 1992.