"It might hit the U.S. as early as Sunday," said National Hurricane Center meteorologist Jack Bevan, and if so, it could be a Category 3 storm.
"One of our computer models is driving Jeanne all the way across Florida into the Gulf of Mexico before the turn begins. We just got a run of another computer model that actually turns the storm soon enough that it completely misses the Florida east coast. The other models are somewhere in between," Bevan told CBS station WFOR-TV. "Right now, it's just too early to say what's going to happen."
The fears of more flooding, devastation and power outages sent many people scurrying to local grocery and hardware stores, stocking up on supplies that quickly ran low before the last storms. State and federal officials geared up for another disaster response.
"We're obviously stretched here. ... To prepare for another storm will stretch our resources, but we have a duty to do this, and we will," Gov. Jeb Bush said Thursday.
Jeanne could slam into Florida just over a week after Hurricane Ivan thrashed the Panhandle Sept. 16. Ivan and the two previous storms, Charley and Frances, caused billions of dollars of damage and were blamed for at least 70 deaths in the state.
A hurricane watch was issued Friday morning from Florida City near the state's southern tip to St. Augustine. The watch for most of the state's east coast means hurricane conditions with winds of at least 74 mph are possible within 36 hours.
Jeanne was expected to reach Florida by Sunday, according to the National Hurricane Center in Miami. It had top sustained winds of 100 mph, but could strengthen as it reaches warmer waters closer to Florida's coast.
An eventual turn to the northwest was predicted, but it was unclear if that would happen before Jeanne reached Florida. Computer models showed possible landfall anywhere from South Florida to Cape Canaveral.
Because the storm was forecast to be so close to Florida, the state is "going to have impacts no matter what," said Lt. Dave Roberts, a meteorologist at the hurricane center.
The only other time four hurricanes hit the same state in one season was in Texas in 1886, National Hurricane Center Director Max Mayfield said.
Survivors who were left with almost nothing after Jeanne devastated the town of Gonaives, Haiti, buried unclaimed corpses in mud-clogged backyards and attacked aid trucks and even neighbors bringing them food.
"You don't want to make me use this!" one man screamed as he waved a wrench at people carrying cauldrons of food to distribute at a church. The volunteers had come from the port of St. Marc to Gonaives, where flooding from the storm killed at least 1,100 people.
Hungry and thirsty survivors — some of whom have lost entire families and everything they own — were losing patience at the slow pace of relief.
Knee-deep mud sucked up animal carcasses and sharp pieces of torn-off zinc roofs, as well as human excrement after the sanitation system was destroyed.
Tropical Storm Ivan sloshed ashore Friday morning near the southern Texas-Louisiana border and was downgraded to a tropical depression, bringing with it heavy rains, strong winds, but nowhere near the devastation it caused as a Category 4 hurricane last week.
"All the emergency crews were on alert, but it was a quiet night," reports CBS News Correspondent Rob Milford in Beaumont, Texas. A flood watch continues for southeast Texas for the weekend.
Scientists say Atlantic and Gulf Coast states may be entering a period of heavy storm activity after a relatively quiet phase. Florida has been spared in recent years and landfall statistics are likely to balance out over time, Mayfield said.
"We've just reached some level of normalcy and here it comes again. I've never seen anything like this," said Margaret McFarlane, of Greenacres. "We've already refilled our refrigerators, gotten the debris out of the streets and it's going to happen all over again. I'm not sure how much more people can take."
For insurance carriers, this has been a hurricane season of massive loss, one they say is painful, but affordable, reports CBS News Correspondent Mark Strassmann. After Hurricane Andrew and its record $26 billion in losses, Florida's insurance industry reorganized, increasing its deductibles, rewriting policies to its highest risk customers and building a massive stormy day fund.
"We're very confident that we will be able to handle any claims that come our way.," said Loretta Worters of the Insurance Information Institute.
Though it wasn't clear exactly where the storm would hit, Kennedy Space Center director James Kennedy ordered the base closed to all nonessential personnel Friday.
NASA's spaceport is still trying to repair damage caused by Frances. Gaping holes remain in the massive Vehicle Assembly Building, where space shuttles are attached to their booster rockets and external fuel tanks before launch.
Other disruptions included the postponement of Florida International University's home opener against Western Kentucky when that school determined it was better for its athletes not to travel to South Florida this weekend.
The Miami Dolphins and Pittsburgh Steelers are considering moving up their game a day to Saturday. The Steelers will fly to South Florida on Friday, one day ahead of their typical travel schedule.
Jeanne was blamed for more than 1,100 deaths in Haiti, where it hit over the weekend as a tropical storm and caused major flooding. Because parts of Florida are already waterlogged, flooding could be a major problem again.
The previous hurricanes have saturated many canals, rivers and lakes. In Seminole County, the swollen St. Johns River is receding but Jeanne's rains could raise the waters again. Currently, there's moderate flooding on a 30-mile stretch but no serious damage has been reported.
"It's just going to be another waiting game," Sanford fire inspector Mark James said. "You can't predict how much is going it's going to do."
Two other tropical systems were spinning Friday, but none of them threatened Florida. Hurricane Karl began to weaken as it moved north in the open Atlantic, and tropical depression Lisa appeared to be following Karl.