David, a huge hurricane that has already killed more than 650 people, aimed at south Florida late tonight and forecasters said it would strike the coast by daybreak.

With David's winds picking up speed as it moved over warm ocean waters, evacuation of beach areas in metropolitan Miami communities continued through the night, in response to the urgings of Gov. Bob Graham, who issued an evacuation order this afternoon. The Red Cross is operating 50 evacuation centers on high ground, mostly in schools.

More than two million people live in southeast Florida's coastal communities, and officials estimate that perhaps 80 percent -- many of them elderly retirees who have moved here in the past decade -- have never experienced a hurricane.

Miami was last hit by a hurricane in 1965, and a radio call-in show today was swamped with calls, mostly from women asking the same basic questions: "I am 77 and I live on the 16th floor of a condominium. What do I do?"

Only their ages and floor numbers changed from call to call.

Besides the potential threat to life, there is a major threat to property. Much of south Florida has been built up since the last hurricane, and condominiums, mobile homes and subdivisions occupy once-vacant territory.

In some mobile home developments where evacuation was begun today, reportedly some residents declined to leave in the belief that they were safe.

Residents of the Florida Keys, who number about 60,000, had basically evacuated on Saturday -- at least those who were not going to ride it out. But as David turned more to the northwest and thus aimed more at the coastal areas, officials declared a hurricane "warning" from Cape Canaveral to Marathon Key. A less serious advisory, a "watch," was in effect from Canaveral north to Jacksonville, and southwest from Marathon to Key West.

David, the strongest Caribbean hurricane of this century, was about 85 miles southeast of Miami at 2 a.m. Monday and was moving northwest at 12 to 15 miles an hour. Its winds reached out 100 miles in front, and weather officials urged residents to complete their preparations quickly.

David had packed winds of more than 150 miles an hour until the mountains of the Dominican Republic and Haiti deprived it of the air currents from warm ocean water on which hurricanes thrive. At one point, it was still barely of hurricane force, 75 miles an hour.And then it began to rebuild.

As it left the Bahamas it was still in the least severe of the National Weather Service's five classes of hurricanes, but the director of the National Hurricane Center here, Neil Frank, said the storm was intensifying.

Graham's evacuation urging in mid-afternoon brought a new pitch to preparations that had been marked by long gasoline lines, by stores sold out of candles, batteries, radios and fuel for lanterns, and by residents cloistering in hotels.

There were long lines at lumber yards, selling sheets of plywood and paneling to be nailed over windows of homes and stores. One entire shopping center had the look of an adult bookstore there that always does its business behind boarded-up windows.

But if the evacuation was a precaution, some residents did not see it as a necessity. As the rising surf and quickening waves rushed at Miami Beach, Mary Wrohl, 78, sat with a gold blanket in the lobby of the Tarleton where she has lived for two years since moving to Miami Beach form Brooklyn. "It's the first and I hope it's the last," she said. "I don't know why we're going. This is a good building. They're schlepping us somewhere else where it's supposed to be better. I wouldn't go away if I didn't have to."

She is one of about 30 elderly retirees who live year round in the hotel -- only a few hundred feet from the Atlantic, where tides are expected to surge to eight or 10 feet when David hits.

South of Miami, in the little town of Tavenier on Key Largo, bartender Faye Andrews, 41, at Harry's Place was doing a bustling business among key residents who hoped their cinderblock homes would stay above the advancing tidal surge, which represents much of the danger of a hurricane.

"I wouldn't feel any better up in Miami," added retiree Doug Matthews, 70.

"Same here," said Andrews. "I feel safer here than in Miami. They flood when it rains hard."

To the north of Miami, a Broward County civil defense official reported that "not too many people are taking us seriously" on the recommendation to evacuate.

About 50 refugee centers have been established and all Red Cross volunteers have been told to report for work. At Dade County's Jackson Memorial Hospital, health facilities were beging overwhelmed by people just looking for shelter, and hospital officials were urging people not to come unless they truly needed medical attention.

While the National Hurricane Center received data from reconaissance planes flying continuously in hurricane David, airlines announced their last flights out -- a staggered cutoff ending at 10 p.m.

The governor's evacuation message stressed low-lying coastal areas of Dade and Broward counties and the upper keys.

Residents in such areas as Miami Beach, Key Biscayne and the little Biscayne Bay islands were urged to complete their evacuation before roads were blocked by storm tides. Ed Ball, assistant city manager of Miami Beach, said the evacuation was going well, including the southern part of Miami Beach, where many poor elderly retirees have taken up residence in recent years.

Last summer, Frank of the hurricane center had expressed concern over evacuation plans.

"There are coastal locations where the population concentration is so large," he said. "Evacuation is impossible on the existing roads with the lead time we can provide with our warnings. Other places will soon attain this same saturation level if developers and planners continue to ignore the hurricane problem."

He also said that, because so many residents had never experienced a hurricane, they might be apathetic about its danger.

Now Florida will have a chance to see how the population boom and economic development of the '70s bear up under hurricane winds.