Hurricane Frances broke apart its eye and put it back together again. It went slow, and then it went really slow -- cutting the pace enough that it is now expected to arrive on land much later than originally predicted.

With its almost hourly whims, Frances taunted millions of Floridians on Friday as it ground across the upper Bahamas and zeroed in on a densely populated coastline in the throes of the largest evacuation in state history. The huge storm, though still subject to diversions that could alter its course, is projected to make landfall with winds of more than 100 mph by late Saturday on Florida's east coast near Vero Beach, 100 miles south of Orlando.

The stakes of the storm were nowhere more apparent than on the almost deserted streets of Vero Beach, a throwback-to-the-1950s beach town best known as the home of Dodgertown, a beloved baseball spring training complex. Police officers picked through neighborhoods there and in neighboring communities, such as upscale Indian River Shores, looking for residents who refused to evacuate. The officers asked the holdouts to sign and fill out a simple form; it lists their next of kin.

"We collected about 30 of those forms," said Public Safety Director Hugh A. Cox. "I think more than 95 percent of the residents have left."

But not Jerry Weick, the chairman of the Indian River Shores Planning and Zoning Board, who brought a sense of a grand experiment to the day.

"I feel safer here than going out on the road," said Weick, whose home is about 500 feet from the surf. "I'm also curious to see what might happen, to be honest with you."

No one knows for sure how many people such as Weick are out there. Millions have been urged to evacuate. There have been indications that the order is being taken seriously, with westward roads clogging with heavily stuffed cars. But there were also many coastal towns in which residents went about their daily routines, walking dogs or jogging. As always, the mobile home parks were the most worrisome for emergency officials. Miami-Dade County Mayor Alex Penelas stood before a bank of microphones and pleaded with 750 people living in mobile homes -- the last holdouts in a county that has 10,800 mobile homes -- to move into hurricane shelters.

Thousands have already poured into shelters, which opened this week over a huge swath of Florida. In the Daytona Beach area, for instance, all 23 shelters were full on Friday, and the surrounding hotels were booked. More than 250 miles to the south, 7,000 people lay out on cots and air mattresses in Miami-Dade County.

The image of the day was the ubiquitous "cone of error," as the meteorologists call it, a light bulb-shaped form displayed on countless television screens that designated the areas threatened by Frances. The cone spreads out across much of the state and into the southern portions of Georgia and Alabama. Before getting there, though, the storm is projected to slice through the center of Florida, weakening as it goes but still dangerous, and could threaten densely populated areas on the west coast, such as Tampa.

The storm had been churning through the Bahamas about 12 mph but slacked off to 9 mph, then slowed to about 6 mph, T.N. Krishnamurti, a meteorologist at Florida State University, said. Slow-moving storms can sit over a region and saturate the ground, causing flooding.

Meteorologists believe Frances may have slowed because its eye inexplicably began to come apart, a not-uncommon phenomenon that scientists have yet to completely understand. Word of Frances's deteriorating eyewall spread quickly, with some hoping it lessened the threat of damage. But officials were quick to urge caution.

"What we have offshore is a monster," Rep. E. Clay Shaw Jr. (R-Fla.) said Friday morning. "With the deterioration, what we have is a monster without a brain."

Later, Frances rebuilt its eye, hardening its core of heavy winds that can cause the most damage. By late Friday, the hurricane's winds were holding steady at 105 mph, down from a peak of 145 mph but still capable of causing a storm surge of six to eight feet and heavy rain.

Michael D. Brown, the head of the Federal Emergency Management Agency, said he would call in more than 4,000 emergency workers from as far away as Oregon, Texas and Maine to help with the relief and recovery efforts after Frances passes. That is in addition to 1,500 FEMA workers who have been in Florida for three weeks since Hurricane Charley slammed the state's west coast and worked up through Orlando, causing $7 billion in damage and killing 27 people.

Comparing the two storms -- Frances is twice as big as Charley -- was irresistible for meteorologists. But now they have something else to talk about: Ivan, a tropical storm in the Caribbean forecast to become a hurricane this month.

Benjamin is a special correspondent. Roig-Franzia reported from Miami Beach. Staff writers Darryl Fears in Daytona Beach and Christopher Lee in Washington and special correspondent Catharine Skipp in South Miami contributed to this report.

Mel and Charles Laessia read while people pass by at a Port St. Lucie, Fla., hurricane shelter. National Hurricane Center Director Max Mayfield, left, examines data while forecaster Lixion Avila confers with other regional meteorologists during a conference call.