The spokeswoman said that a forecast at 5 p.m. on Thursday caused county officials to react, readying shelters and helping residents seeking to evacuate.
Starting on Saturday morning, lines that were several blocks long formed outside of shelters such as the Germain Arena, as residents jammed inside.
In Fort Myers, which is in Lee County, buses that were transporting people to shelters stopped running at 3 p.m. to allow the drivers to seek safety, potentially leaving people who had not left their homes in time.
By late Saturday afternoon, all of the shelters in Collier County were at capacity, according to local news reports. Because of the imminent storm surge, officials told people living in one-story homes to try to enter shelters anyway, and people in two-story homes to seek shelter upstairs.
In Miami-Dade County, some people who had flocked to shelters were reassessing their situation on Saturday afternoon after learning that the brunt of the hurricane would most likely be felt farther west.
âWeâre going home,â Virginia Lopez, an administrative assistant at Barry University, said as she loaded her 5-year-old poodle mix, Princess, into her Mazda outside a shelter at Highland Oaks Middle School after spending the night there with her daughter and son-in-law. âWe decided half an hour ago. The storm has moved to Tampa, so weâre going to get a lot of rain but it wonât be as bad. I donât feel so scared.â
Inside, dozens of people lay on cots and blankets in the buildingâs hallways amid a stench of perspiration and vomit. Some were packing to leave but most seemed resigned to remaining until the storm blows through.
Florida Keys face being cut off
In the Florida Keys, where the hurricane is expected to make landfall on Sunday morning between Marathon and Key West, emergency officials girded for a direct hit and residents who did not evacuate began to take cover as the winds kicked up sharply Saturday afternoon.
The Keys, a thin chain of low-lying islands, are especially vulnerable to Hurricane Irmaâs anticipated powerful tidal surges.