Two hurricanes are now taking aim at Hawaii.
The first, Hurricane Iselle, packed 90-mph winds Wednesday night as it chugged west toward the islands. Meteorologists said it had strengthened somewhat and was expected to remain at hurricane strength when it makes landfall sometime late Thursday.
The trailing system, Hurricane Julio, was upgraded from a tropical storm Wednesday. Carrying 85-mph winds, it was expected to the north and clip Hawaii on Sunday night.
Neither storm by itself would be expected to pose major problems, but the one-two punch could create quite a bit of damage, forecasters told NBC News.
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Gov. Neil Abercrombie signed an emergency proclamation and encouraged islanders to make plans. People flocked to stores to stock up on bottled water and other supplies.
Mike Kelley, manager of the Cost-U-Less store in Hilo, told NBC station KHNL of Honolulu that the store had sold "a lot of rice, water, toilet paper. Bottled water was sold out, with no new shipments expected until Thursday or even Friday, he said
Hawaii is also holding primary elections Saturday for races including a Senate seat, the governorship and the House seat that represents Honolulu. Some islanders are voting early ahead of the weather.
When Isele strikes, "we'll have power outages likely from all the wind, and maybe some flooding, as well, from all the heavy rain," said Ari Sarsalari, a meteorologist for The Weather Channel.
The two tropical systems are being steered west toward the islands by the underside of a high-pressure system in the Pacific Ocean. A hurricane warning was posted Wednesday for the Big Island of Hawaii, and Maui, just to the west, was under a tropical storm warning. Kauai County was under a tropical storm watch.
Hawaii hasn't been hit by a tropical storm or hurricane at all since 1992. And the one-two punch would be unprecedented in the era of satellite hurricane tracking, said Kevin Roth, a meteorologist for The Weather Channel.
The closest similar occurrence was in the summer of 1982, when a weakened Tropical Depression Daniel struck Hawaii and was followed 10 days later by Tropical Storm Gilma.
— Erin McClam and M. Alex Johnson