KAILUA-KONA, HAWAII: Hurricane Madeline weakened to a tropical storm on Wednesday as it advanced toward Hawaii's Big Island, where residents were bracing for strong winds and rain even as another storm across the country continued its path to Florida, officials said.

Hawaii officials opened shelters and closed offices, schools and roads on Wednesday to prepare for Madeline, which is expected to pass just south of the Big Island.

"We should all be hunkering down as the storm passes," said Hawaii County Civil Defense spokeswoman Kanani Aton.

Madeline, as it weakened with sustained winds of about 70 mph (113 kph) on Wednesday afternoon, was about 75 miles (121 km) southeast of the Big Island, said Central Pacific Hurricane Centre meteorologist Ray Tanabe.

The tropical storm, before it moves westward out of reach of Hawaii, could dump as much as 15 inches (40 cm) of rain on parts of the Big Island, according to the National Weather Service. The storm already was lashing the island with rain and wind, resulting in some road closures, Tanabe said.

Hurricane Lester, currently a major Category 4 storm, could affect Hawaii over the weekend.

Hawaii Governor David Ige signed an emergency proclamation that runs through Sept. 9, freeing up state resources.

Off the mainland United States, Tropical Storm Hermine, with winds gusting at 45 miles per hour (75 km), was forecast to strengthen as it passed through the Gulf of Mexico before reaching Florida's northern Gulf Coast Thursday afternoon, and then sweep across northern parts of the state with pounding rains, then northeast along the Atlantic Coast.

As the projected path jogged west, forecasters extended a hurricane watch and tropical storm warning to Destin, in Florida's Panhandle, and on to the Anclote River north of Tampa.

Florida's governor declared an emergency on Wednesday ahead of the brewing storm.

Heavy rains were already pounding parts of the state on Wednesday. As much as 20 inches (50 cm) could fall over northwest Florida, the National Hurricane Centre in Miami said, warning of storm surges and "life-threatening inundation." Many school districts along the Gulf Coast canceled after-school activities and ordered students to stay home on Thursday.

On its current path, the system would dump as much as 10 inches (25 cm) of rain on coastal areas of Georgia, which was under a tropical storm watch, and the Carolinas.

Lori Hebert, 40, woke up on Wednesday to flood waters seeping into her house in the Tampa Bay region. Catfish came onto her driveway as the street flooded in Gulfport, a small waterfront city.

"We haven't gotten the main storm yet," she said, loading a dozen sandbags into her van.

US oil and gas producers in east of the Gulf of Mexico removed workers from 10 offshore platforms, moved drilling rigs and shut some output because of the storm.