NAPLES, Fla. (AP) - Hurricane Wilma crashed ashore early today as a strong Category 3 storm, battering southwest Florida with 125 mph winds and pounding waves as it began a dash across the peninsula.

The storm flooded low-lying areas and knocked out power to more than 300,000 homes and businesses in the Keys and in such areas as Miami and Fort Lauderdale.

Wilma, Florida's eighth hurricane in 15 months, made landfall at 6:30 a.m. near Cape Romano, 22 miles south of Naples, bringing with it a potential 18-foot storm surge, the National Hurricane Center said.

Up to 10 inches of rain and tornadoes were forecast for parts of central and southern Florida.

Hurricane-force wind of at least 74 mph extended 90 miles from the center and tropical storm-force winds reached 230 miles, the hurricane center said. The storm strengthened in the hours before making landfall.

‘‘I looked out our place and I saw a bunch of stuff flying by,'' said Paul Tucchinio, who was riding out the storm in a condo three blocks from the beach in Naples. ‘‘It sounds like someone threw a bunch of rocks against the boards. It's wicked.''

By 7 a.m., the storm's top sustained winds had weakened slightly to 120 mph, but it was still a Category 3 and was not expected to weaken much as it roared quickly across the state toward heavily populated Miami-Dade, Broward and Palm Beach counties.

More than 33,000 people were in shelters across the state. But in the low-lying Florida Keys, not even 10 percent of the Keys' 78,000 residents evacuated, Sheriff Richard Roth said. Key West was getting sustained winds of 60 mph, with gusts of 76 mph.

Key West Police Chief Bill Mauldin said the city had severe flooding just before dawn, ‘‘more extensive than we've seen in the past.'' But he wouldn't know until daybreak the full extent of any damage.

At 7 a.m., Wilma was about 10 miles north of Everglades City and moving northeast at about 23 mph.