The forecasters had fiddled with the storm track for days, nudging it to the east and then pulling it back to the west, but when Hurricane Irma finally blew in Sunday, it reminded everyone that when a tropical cyclone reaches a certain size, it simply can't miss.

This storm was nearly as big as the state of Florida, which is why everything but the Panhandle was under a hurricane warning. Irma’s broad wind field also meant that when the winds picked up, they stayed up as the storm howled northward.

Even cities far outside the eye of the storm found themselves caught in an atmospheric blender that had no off switch. Patience suddenly became as important as a sturdy roof and reliable drainage.

“Anyone think we overreacted with the evacuation order?” Michael Hernández, spokesman for Miami-Dade County, asked late Sunday morning at the county Emergency Operations Center.

As he spoke, one TV monitor showed a huge, collapsed construction crane downtown, draped on a building as though it had melted in the rain, and another showed a wide river of floodwater racing down Brickell Avenue, Miami's financial district and once the neighborhood of pop star Madonna.

What’s in the path of Hurricane Irma

The storm’s westward shift was good news for South Florida’s Gold Coast but very bad news for Key West, as well as Naples, Fort Myers, Port Charlotte, Sarasota, St. Petersburg and Tampa — table-flat waterfront communities that have boomed in recent decades with millions of new residents but haven’t gained more high ground.

In Estero, Dianne and Riley Abshire, who moved to Florida six years ago from Ottawa, Ohio, waited for Irma in a home darkened by hurricane shutters. Winds at the time gusted to 45 miles per hour. Hibiscus trees bent to the ground. Tornado watches and warnings flashed across their television screens. They chose to stay in their home because they worried about traffic getting out of the state and because Riley Abshire is recovering from surgery.

“I feel like I’m in a sardine can, and I don’t like it,” said Dianne Abshire, 62. “My husband said he’ll duct-tape me to a chair if I try to open the front door.”

In Bonita Springs — between Naples and Fort Myers — on Sunday morning, streets that were empty but for a few emergency vehicles started filling with runoff that was not running off. Officials announced they would pull everyone off the roads at 11 a.m.

A Waffle House on Bonita Beach Road had posted a sign promising, improbably, that it would reopen soon.

More than 30,000 people flocked to Collier County’s shelters, including about 4,000 in the massive Germain Arena, which was still accepting people at 10 a.m. But a wild rumor spread on social media that the arena was unsafe, and that set off “mass hysteria,” according to a Lee County spokesman. Tim Engstrom, communications specialist, said officials were trying to reassure residents that the venue was hardened against hurricanes. “We don’t have much information, but this is absolutely false,” Engstrom said as the hurricane approached steadily.

In Pasco County, north of Tampa, sheriff’s officers warned citizens not to shoot guns into the air after a Facebook page that suggested shooting Irma out of the sky went viral.

“The bullet trajectory could come down and hurt individuals,” said Pasco County Sheriff’s spokesman Doug Tobin, noting that there were no reports of anyone actually trying to shoot the hurricane.

The lower half of the nation’s third-most-populous state went into lockdown as residents rode out the big blow and wondered when it would end. The storm took its time rolling in from the Caribbean. When it arrived, there was no mistaking what this was — not an ordinary line of storms but a true-blue hurricane, the powerful winds interrupted by even more powerful gusts and rain coming down in blinding quantities.

Everyone watched the slow-moving, ominous green blob that represented Irma on more than a dozen computer screens at the National Hurricane Center overnight Saturday. A handful of journalists, federal government workers, hurricane specialists: Everyone monitored the radar maps of the monstrous storm’s snail-paced path as it prepared to batter Florida.

Figuring out what the outskirts of the storm were doing right outside the building in Miami, however, was harder to determine.

“You hear the rain on the roof?” a videographer inside asked on Friday evening.

“I think that’s the AC,” someone responded.

“No, it’s the rain,” he said, this time pointing to the ceiling so everyone would listen more carefully.

“Yeah, it’s the AC,” the room decided.

The steel-clad National Hurricane Center was the best place to track the storm on a digital radar system but the worst to actually see and hear the storm in real life.

As soon as tropical storm-force winds kicked in Saturday evening, steel shutters closed over the building’s doors. No one was allowed in or out. Total lockdown.

Reporters slept on the floor as National Hurricane Center employees worked through the night, delivering updates on the top of every hour and answering the same questions over and over from television and radio hosts on the phone.

“How big will the storm surge be on the southwest coast of Florida?” the journalists would ask multiple times each hour.

“Ten to 15 feet,” Ed Rappaport, the acting director of the National Hurricane Center, would calmly respond, stressing again and again that this was a life-threatening hurricane.

As Rappaport addressed the nation, he said he had no firsthand knowledge of what the weather was doing outside his office.

“There are no windows here. I rely on the media to know what’s going on,” he said with a smile as he pointed to a local TV newscast playing above him.

The lights began flickering on and off at about 8 a.m. Sunday morning in the Pompano Beach High School cafeteria, which was serving as an evacuation shelter for about 225 people. An hour later, the building plunged into darkness, causing many people to gasp. But then the lights came on again, thanks to a generator that performed the way it was designed to.

The shelter is about three miles from the state’s east coast in the Broward County jurisdiction, where tornado warnings were also being issued. The county is under a curfew that is not expected to be lifted until 10 a.m. Monday.

Laurie and Steve Trinkle, their 12-year-old twin sons and Laurie’s 85-year-old mother, Mildred, went to the shelter shortly after noon Saturday but decided to vacate the crowded premises about 12 hours later. “I think we’ll be more comfortable at home as long as the power stays on,” Laurie Trinkle said.

It did not, at least at the shelter, and according to one of eight police officers on duty 24/7 in the building, it was lights out all around Pompano Beach and nearby towns.

The school generator was designed to keep the lights going, but that was all. The two big-screen televisions keeping evacuees informed about the storm went black. The scores of electrical outlets around the room were no longer working, nor were the microwave ovens and the refrigerators storing food. Perhaps most significantly, the air conditioning was out of service, as well.

Despite a sign on the front door warning everyone to stay inside, several people wandered into the wind, protected from the rain by an overhang, just to watch the palm trees swaying and palm fronds littering the lawn out front. Some just wanted to sneak a smoke, forbidden inside.

In much of South Florida, residents had been furiously preparing for the hurricane since Tuesday, if not earlier. The virtue of improved five-day hurricane-track forecasts is that people have more time to get ready. The downside is that a city could effectively shut down for the better part of a week.

Saturday was so off-and-on stormy, with such long patches of calm weather, that a person could easily have been lulled into thinking that Sunday would be easy. That illusion was punctured by raging weather before dawn.

A return to normalcy could take a while given that the storm knocked out power to nearly 2 million Florida Power & Light customers in South Florida alone.

A reconnaissance of the area by car Sunday morning revealed an eerily empty city, with stop signs flattened, palm fronds littering the streets, tree debris blowing around like tumbleweed.

The front doors were locked at the Aloft Hotel, which had a full house, including stranded international travelers.

But the hotel still had power: Breakfast was served; the coffee was fresh. The hotel has large windows, for excellent viewing of the storm.

“No fear, no pain,” said Sergio Pallette, 58, of Argentina. He and his wife were supposed to fly out Friday, but their flight was canceled because of the weather.

When will he go home?

“When they finish the hurricane,” he said.

Also up and about: storm-chasing journalists.

“I’ll be back in Guam by next week,” said Caroline Graham, a Los Angeles-based reporter for the United Kingdom’s Mail on Sunday, who had been covering the tension between the United States and North Korea before winding up at the Aloft to cover Irma.

She noted the dizzying pace of crises hitting the United States.

“Nobody’s talking about Harvey now. America’s crazy right now. Between Trump, Mother Nature and North Korea, I haven’t stopped.”

By the end of the day, Miami was still being raked by powerful wind gusts with intermittent lulls. Driving was rendered dangerous not only from flying objects but from trees and debris on every road surface. Most streetlights were out, and the legal injunction to treat all intersections as if they were four-way stops was rarely observed. There was the constant hazard of falling objects, trees, poles and signs. At flooded Brickell Avenue, a 6 p.m. wind gust ripped a large piece of metal from a skyscraper and dropped it on the avenue just a few yards from two idling cars. The makers of billboards wisely use tearaway fabric, which creates a storm-ravaged appearance but keeps the billboards from getting blown over.

Brickell’s floodwaters did not appear to be in retreat. David Hall, 22, and a friend used their pickup truck to haul a disabled car from where it had beached in high water along the avenue’s median. “It’s intense, scary,” Hall said. “It’s a real mess, my friend.”

Shapiro reported from Pompano Beach and Stein and Achenbach reported from Miami. Lori Rozsa contributed to this report from Gainesville, Fla.