HONOLULU (AP) -- For about a week, the sunshine Hawaii is normally famous for has been replaced with thunderstorms and large pieces of hail.
A 30-minute hail storm Friday over windward Oahu was "unprecedented," for Hawaii, said Tom Birchard, senior meteorologist for the National Weather Service in Honolulu. Not only is it highly unusual for hail to fall over Hawaii, but some stones that measured as large as three inches are likely record-breaking, he said.
Small stones were reported to have fallen on other islands over the course of about a week of heavy rains over parts of Hawaii that closed schools, caused sewage spills, flooded homes and dampened vacations. There were landslides, power outages and roads blocks by trees, boulders and mud.
Cold weather in the middle and upper levels of the atmosphere has led to strong updrafts that kept the ice chunks from melting into rain before hitting the ground, Birchard said. Thunderstorms were in Friday's forecast but heavy rains were expected to subside by Saturday.
It's the tail end of Hawaii's rainy season. "The rain is not all that unusual but the hail and strength of the thunderstorms are unusual," he said.
A section of a roof blew off a house and traveled several hundred yards in Kailua, prompting officials to send a meteorologist to see if the cause was straight-line winds or a waterspout that moved ashore into a tornado, Birchard said.
The weather service was still compiling total rainfall amounts but Birchard said records will likely be broken. For the seven-day period ending Friday, the highest rainfall level was nearly 46 inches in Hanalei on Kauai.
Visitors to tourism-dependent Hawaii were urged to check weather advisories and warnings and to follow all recommendations. "As the storm continues to pass through our Hawaiian islands, we remain open for business," said Hawaii Tourism Authority President and CEO Mike McCartney.
Mike Zellman was hoping to trade cold weather in Hamburg, Germany with sunshine in Hawaii. He and his wife, clad in windbreakers, spent Friday afternoon at the state Capitol and planned to take refuge from the showers in a Honolulu shopping center.
"In the morning, we wanted to go to Diamond Head but it was closed because of the wonderful weather," he said sarcastically. The weather has affected "everything" during the their three days on Oahu so far: "Beach time. Nature time. The landscape," he said.
While there were reports of hotels crowded by guests stranded from canceled flights, George Costa, director of Kauai's Office of Economic Development said hotels were faring well as rain subsided Friday. "There are several road closures due to landslides and most of the inconvenience is being experienced by the resort staff not being able to report to work," he said.
Defense Secretary Leon Panetta told a crowd at U.S. Pacific Command headquarters for a ceremony that it was nice to be in Hawaii, "rain and all."
"The rain here is not the same as it is elsewhere, It has a different flavor to it," he said. The ceremony was moved indoors to an auditorium.
Gov. Neil Abercrombie declared a disaster for Oahu and neighboring Kauai, which were the first islands to see the brunt of the storms starting last weekend. Since Monday, nearly 100,000 gallons of a heavy mixture of storm water and untreated wastewater spilled into streams during five different sewer spills on Oahu, city officials said.
As the weather system moved on to Maui and Molokai, they also battled flooded homes and blocked roads. Firefighters were called to a Molokai home where residents were knee-deep in water. The Department of Water Supply advised central and south Maui to boil water before drinking as a precaution avoid possible contamination with rainwater.
The Coast Guard warned mariners to brace the vessels for gusty trades forecast for into next week. A small craft advisory was issued for all waters around the islands, which will be vulnerable to a line of thunderstorms producing strong winds of nearly 40 mph or greater and possible waterspouts.
At least six boats broke away from their moorings within the past week and one boat sank after being struck by lightning Monday.
Associated Press writers Audrey McAvoy and Treena Shapiro contributed to this report.