Hurricane Frances weakens slightly
Storm downgraded to Category 2 but still 'dangerous'
This radar animation shows the storm's progress from 5:45 a.m. to 4:45 p.m. Friday ET.
CNN's Kathleen Koch on Floridians boarding up on the state's east coast.
CNN's John Zarrella on getting an emergency kit together.
Pinpointing a hurricane's landfall remains difficult.
2 a.m. Saturday ET
Position of center: About 135 miles (217 kilometers) east of West Palm Beach, Florida
Latitude: 26.4 North
Longitude: 78.0 West
Top sustained winds: Near 105 mph (170 kph)
Map: Projected path
Source: Natl. Hurricane Center
MIAMI, Florida (CNN) -- Just weeks after Hurricane Charley tore through Florida, Hurricane Frances aimed for the Sunshine State Saturday morning, packing winds of 105 mph and bringing the potential for up to 20 inches of rain.
Charley was a compact storm with heavy winds that moved quickly across the state.
In contrast, Frances is as big as the state of Texas -- twice the size of Charley -- and is moving slowly over the ocean.
Once Frances finally hits, it is expected to slow to a near crawl, dumping 7 to 12 inches of rain in its wake and possibly as much as 20 inches on some areas.
By Sunday afternoon, the storm is expected to still be over parts of Florida, according to Eric Holweg, a meteorologist with the National Hurricane Center.
"It's going to be a very slow mover, so the potential for freshwater flooding is a real possibility," Holweg said.
When Hurricane Charley arrived three weeks ago, most of the damage was related to wind.
In advance of Hurricane Frances, the state has ordered the largest evacuation in its history, covering nearly 2.5 million people.
Gov. Jeb Bush has declared a state of emergency.
Forecasters predicted landfall Saturday afternoon in the middle of Florida's eastern coast. The storm was expected to move over the northwestern Bahamas early Saturday.
The storm was downgraded late Friday to a Category 2 hurricane with maximum sustained winds of 105 mph (168 kph), but forecasters warned the storm could strengthen as it moves over warm waters between Florida and the Bahamas.
"That might give it a little extra kick," Holweg said. "The possibility is quite real that it could intensify."
The National Hurricane Center reported at 2 a.m. ET that the storm is centered about 45 miles (70 kilometers) east of Freeport, Bahamas, and about 135 miles (217 kilometers) east of West Palm Beach, Florida.
Although it's wobbling, the storm was moving toward the west-northwest at about 6 mph (9 kph).
Even as a Category 2, forecasters said, Frances still is "a dangerous hurricane."
Hurricanes are classified as categories 1 to 5 on the Saffir-Simpson hurricane scale. A Category 2 storm has sustained winds between 96 and 110 mph (154 and 177 kph).
Hurricane-force winds extend 85 miles (140 kilometers) from the center of the storm, and winds of tropical storm strength (39 to 73 mph) extend outward up to 185 miles (295 kilometers).
By Friday afternoon, parts of Florida were experiencing wind gusts as high as 39 mph -- the lower end of tropical-storm intensity.
Hurricane warnings are in effect for much of Florida's eastern coastline. A hurricane warning means hurricane conditions are expected in the warning area within 24 hours.
With the storm approaching, Walt Disney World in Orlando said its parks would likely be closed Saturday, though its resort hotels will remain open.
Airports in Orlando, Fort Lauderdale and Melbourne were closed. (Full story)
Supplies of bottled water and gas canisters were scarce, and plywood was running low in some areas as residents boarded up their homes.
An earlier hurricane center bulletin said Frances was "relentlessly lashing the central and western Bahamas." (Full story)
Storm surge flooding of five to 12 feet above normal has been reported in the storm's path, and the hurricane center warned that "rainfall amounts of seven to 12 inches -- locally as high as 20 inches -- are possible in association with Frances."
Bush said the state was taking all necessary steps to prepare for the storm.
"We are staging across -- some outside the state and some inside the state -- a massive response for this storm, and we're going to need it," Bush said in a news conference. "There's going to be a lot of work necessary to make sure that the response is massive and immediate to help people once this storm comes."
He said he has asked the governors of 17 states to waive size and weight restrictions on trucks carrying relief supplies.
His brother, President Bush, also offered support at a campaign rally Friday morning in Pennsylvania.
"Before I begin, I do know you'll join me in offering our prayers and best wishes to those in the path of Hurricane Frances," the president said.
Florida ordered mandatory evacuations in parts of 16 counties and voluntary evacuations in five other counties.
"If you are on a barrier island or a low-lying area, and you haven't left, now is the time to do so," Governor Bush said.
People looking to flee the region clogged highways Thursday, but officials said Friday that traffic had died down. "Overall we're very, very pleased with evacuation procedures yesterday and continuing through today," said Col. Chris Knight, director of the Florida Highway Patrol. "We have no problems this morning."
The Red Cross opened 82 shelters in Florida on Thursday and about 21,000 people were in them by nightfall, spokeswoman Carol Miller told CNN. The group also set up eight reception centers along the highway to help people who needed information, directions, water and maps, she said.
Miller said the Red Cross was launching its largest-ever response effort to a domestic natural disaster.
Military officials are preparing to evacuate three commands as Frances approaches.
At MacDill Air Force Base in Tampa, on Florida's Gulf Coast, a military team is preparing to set up alternate headquarters facilities for the U.S. Central Command and Special Operations Command at the stadium used by the Tampa Bay Buccaneers football team.
Central Command is responsible for running the wars in Afghanistan and Iraq, while Special Operations Command oversees 50,000 special operations forces.
Patrick Air Force Base, on the eastern coast of Florida near Melbourne, was evacuated Thursday, and the commander of a fighter wing near Miami ordered aircraft moved out of the hurricane's path.
The naval air station at Jacksonville also moved aircraft out of the area.
In Miami, the headquarters of the Southern Command has closed. Command-and-control operations are being performed, but they could be moved to Davis-Monthan Air Force Base in Arizona.
NASA's main launching pad in Cape Canaveral was shuttered.