MIAMI � The center of fierce Hurricane Irma, pushing a dangerous flood of ocean water, made landfall early Sunday morning on Cudjoe Key, just a short drive down the Overseas Highway from Key West.
The storm arrived in the Lower Keys as a Category 4 with howling winds and the National Weather Service Key West office warned that sustained winds of up to 120 mph would continue for hours from Big Pine Key to Key West. A bigger concern was storm surge, which was still rising in the morning. Some social media posts already showed knee-deep water in portions of Old Town and forecasters said seven to 10 feet above ground level was a possibility in some areas.
Mike Brennan, a hurricane specialist at the National Hurricane Center, said that despite Irma's landfall — at 9:10 a.m. for the record — people sheltered in the Lower Keys should stay put until the storm clears out.
"For those in the Lower Keys who may be listening," said Brennan, "you don't want to go outside even if the wind dies down because of the surge."
The center of the eye crossed Cudjoe Key, a residential island long-known for housing Fat Albert, an Air Force blimp. It's just 20 miles east of Key West. The worst winds of the eyewall, caught in satellite loops, passed roughly between Big Pine, home to the National Key Deer Refuge, and Key West, some 30 miles to the west.
With Key West on the weaker side of the storm, it was the hurricane-driven push of water from the Atlantic and Gulf of Mexico that posed the most risk to one of Florida's most famous tourist meccas, a small town renowned for charming gingerbread architecture, fabulous sunsets and quirky characters.
Irma finally struck Florida after a long trek that ripped across a string of Caribbean islands, scoured the north coast of Cuba and sent some 6.5 million Floridians on both coasts fleeing for shelter.
Ed Rappaport, the acting director of the National Hurricane Center, warned Saturday night that Irma was "capable of causing loss of life and major damage." He said water driven into the Keys from Irma could exceed the five to 10-foot storm surge predicted because waves of equal height could ride on top of the surge.
The worst surge will occur near and to the right eye of the storm, the Key West office of the National Weather Service said early Sunday. Storm surge is likely already occurring, they said, and will peak around midday before receding early Monday morning. Hurricane winds extend 80 miles. Tropical storm force winds reach another 220 miles from Irma's center.
As for communities in Irma's path along Florida's west coast, Rappaport said he was very concerned. "They're going to have a very rough 24 to 36 hours," he said.
In the Keys — a famed and picturesque tourist and fishing destination — the rough day was only starting. The island chain had largely been evacuated in advance of Irma, but there were holdouts, particularly in the Conch Republic of Key West. Damage reports from overnight Saturday were minimal but Irma's worst winds had not yet hit. Based on previous strikes from major hurricanes, property losses could be substantial.
At 5:40 a.m. Sunday, the Key West weather service warned in a tweet that hurricane winds were " imminent." When Irma's eyewall crossed halfway across the Keys not long after, the National Hurricane Center declared an official landfall.
The hurricane appeared to begin reorganizing itself early Sunday, with a possible eyewall replacement starting that could weaken the storm but expand the storm's windfield, Brennan said. That could expand winds to the southeast, he said.
But with the eyewall already striking, it likely won't make much difference for the Lower Keys.
"The die is mostly cast," said Brennan.
Irma began its 12-day westward march from the African Coast on Aug. 29. Within a week, it was moving steadily as a dangerous and historically powerful Category 5 storm with sustained winds of 185 miles-per-hour and 225 mile-per-hour gusts. It has already left more than 20 people dead in its wake, not including Cuba, which has yet to survey damage.
The storm weakened somewhat after hugging the northern Cuban coast but regained strength as it approached the Keys early Sunday, which have a long and deadly history of hurricane strikes. Irma was expected to wind up as the strongest hurricane to hit the Keys since Donna in 1960.
(Miami Herald staff writer David Ovalle contributed to this report from Key West.)