The storm is expected to come ashore with up to 20 inches of rain as early as Saturday afternoon, nearly a day later than earlier predictions.
For the 2.5 million residents told to clear out — the biggest evacuation in Florida history — and the millions of others who remained at home, Frances' tardy arrival meant yet another day of waiting and worrying.
The storm is bigger than the state of Texas, reports CBS News Anchor Dan Rather.
"You actually have the worst circumstance here now, a large storm with a slow moving storm," Bob Weismann, who is in charge of West Palm Beach's emergency management, told Rather.
"It's all the anticipation that really gets to you," said Frank McKnight of Wellington, who waited four hours at a hardware store to buy plywood. "I just wish it would get here and we could get it all over with. I want to know now — am I going to have a house left or not?"
A hurricane warning remained in effect for Florida's eastern coast, from Flagler Beach south almost to the state's tip, and Gov. Jeb Bush declared a state of emergency for all of Florida.
At 5 p.m. EDT, Frances was centered about 170 miles east of Miami.
As Frances buffeted the Bahamas, its top wind fell to 115 mph from 145 mph a day earlier. And its march toward Florida slowed to 8 mph. The storm's lumbering pace and monstrous size — twice as big as devastating Hurricane Andrew in 1992 — mean Frances could spend hours wringing itself out over Florida, causing disastrous flooding.
"The storm, unlike Charley and others in the past, will be with us for a long, long time," Bush said.
Bush asked seventeen other states to raise weight restrictions on trucks carrying emergency supplies, so that "the victims will receive emergency assistance from other States as quickly as possible," reports CBS News Correspondent Mark Strassmann.
State meteorologist Ben Nelson said Frances might remain over Florida for two cycles of high tide, meaning two rounds of storm surges expected to be 5 to 10 feet.
"The water has nowhere to go and gets trapped because our elevation is so low," he said. "It could be a large mess."
Wind gusts in Fort Lauderdale and West Palm Beach had already reached 38 mph Friday afternoon. Palm fronds bent in the wind as waves slammed into the beaches. A gust peeled half the roof off a mobile home in Davie, but no one was hurt.
In Miami, which was expected to escape the worst of Frances, winds at the leading edge toppled trees and caused scattered power outages.
Among those evacuated were about 3,000 state inmates and approximately 500 patients at more than a dozen hospitals.
At a Fort Lauderdale marina, Michael Wasserberg checked on his 65-foot boat and worried that many will misjudge the hurricane's ferocity.
"People are hearing that the winds are down to only 115 mph," he said. "Well, if a bug hits you at 115 mph, it will knock your head off."
Frances is expected to come ashore along the middle of Florida's eastern coast, crawl across the state as a tropical storm just north of Tampa and weaken to a tropical depression as it moves over the Panhandle on Monday.
The threat comes three weeks after Hurricane Charley killed 27 people and caused billions of dollars in damage in southwestern Florida. At a campaign rally in Pennsylvania, President Bush spoke of another potential round of devastation for Florida.
"I've ordered teams to be in position to help the good people of that state," he said. "But the best thing we can do here is to offer our prayers."
For the most part, evacuees seemed to be adapting calmly to spending Labor Day weekend in shelters.
Nancy Syphax who said the mood was good at an elementary school in Jensen Beach. "This is a necessary precaution," she said. "I'd rather be safe than comfortable at this moment."
Many schools and government offices closed, as did major amusement parks, the Kennedy Space Center and airports serving Fort Lauderdale, Miami and Melbourne.
The Federal Emergency Management Agency mobilized 4,500 workers, three times the number sent to help victims of Charley. Officials said they had enough people and supplies in the state to handle two disaster-relief operations at once.
The American Red Cross planned a larger relief operation than the one it conducted after Hurricane Andrew. Back then, the agency spent $81 million.
Hurricane season usuallly peaks in early September, and the ninth named storm of the season formed Friday in the far eastern Atlantic. Tropical Storm Ivan was about 865 miles southwest of the Cape Verde Islands with winds of 50 mph.