Hurricane Irma, one of the most powerful hurricanes on record, weakened slightly to a Category 3 hurricane after grinding along the northern coast of Cuba early Saturday. But it is expected to soon head for the Lower Keys with what forecasters expect will be regained strength.
Early Saturday, tropical storm force winds had started lashing parts of the Florida chain of islands, pushing storm surge ashore. Water level was up more than three quarters of a foot in Key West after 10 a.m. and 1.1 feet near Vaca Key. The center of the storm is not expected to pass until Sunday morning, before heading to Florida’s Gulf Coast. Winds well in excess of 100 mph are expected but the real worry is storm surge, which could push the Atlantic into the streets of Key West, Marathon and other islands.
Where Irma ultimately makes landfall on the mainland remains uncertain because of the storm’s angle to the coast, National Hurricane Center forecasters said in their early Saturday update.
The storm’s center could near Tampa Bay, which has not been struck by a major hurricane since October 1921, when the population was about 10,000, said hurricane center spokesman Dennis Feltgen. About 4 million people now live in the low-lying area.
“Big difference,” he said. “They’re incredibly vulnerable.”
On Sunday, the Keys should brace for a “very life-threatening event,” hurricane specialist Mike Brennan said, with storm surge capable of reaching 10 feet above ground level. By 10 a.m. Saturday, winds at Molasses Reef off Key Largo had already reached 39 mph, he said.
While Miami and the southeast coast have dodged a direct hit, Southeast Florida can also still expect dangerous storm surge as strong winds push water inland and feeder bands drop heavy rain.
At 11 a.m. Saturday, Irma was located 175 miles southeast of Key West with slightly weaker sustained winds of 125 mph as it continued to pound Cuba’s north coast, forecasters said. Storm bands had already started reaching Miami, with squally rains and winds just after 7 a.m., signaling the storm’s astonishing reach. A gust on Virginia Key neared 50 mph, where water was already nearly a foot above normal. Miami International Airport recorded a 55 mph gust.
Irma remains massive, with hurricane-strength winds reaching 70 miles from its center and tropical storm force winds extending 195 miles — making it wider than the state. The storm is expected to batter Florida for at least two days, Brennan said. The latest forecast track also crosses dangerously close to Captiva and Sanibel in an eerie repeat of 2004’s Hurricane Charley. But hurricane wobbles are notorious. Forecast tracks can still be off by about 90 miles at two days, Brennan said.
Saturday morning, Irma unexpectetdly plowed ashore on Cuba’s north coast, near Caibarién, a village nicknamed The White Town for beaches that once supported a thriving resort. In 2009, the population was about 38,000.
Moving over land will likely weaken winds, but warm waters in the Florida Straits are expected to recharge the hurricane, forecasters said.
Because Irma is so big, impacts are expected to be widespread, with dangerous and potentially catastrophic storm surge rolling up and down the Florida coast.
Above-ground water levels could reach up to 10 feet along the east coast from Cape Sable to Boca Raton, forecasters said. On the Gulf coast, where the flat continental shelf worsens the threat, the surge could reach 15 feet from the cape to Captiva. Flood-prone Tampa could see three to five feet.
Heavy rain could worsen flooding. Up to 15 inches are possible in the Keys, with up to 20 inches in some places. The Florida mainland is expected to get between eight and 15 inches.
The record-breaking hurricane — Irma accumulated more wind energy in 48 hours than any hurricane ever recorded — has been menacing South Florida for days. Track forecasts earlier pointed it to the urban east coast, home to more than 6 million, triggering frantic preparations. Evacuations were ordered that affected about 680,000 people in Miami-Dade alone. Gas pumps ran dry. Store shelves quickly emptied.
As forecasts began shifting west, taking the storm up the center of the state, evacuations increased to eventually cover nearly 20 counties.
On its current track, Irma is expected to begin crossing the Florida Straits early Sunday. The center of the track crosses close to Cudjoe Key, where Hurricane Georges hit in 1998 and delivered a 10- to 12-foot storm surge, cut off water and electricity to the chain of islands, and left the Lower Keys a ragged mess. Hurricane and storm surge advisories have been widened in Florida and up the U.S. East Coast.
The storm is expected to continue moving west-northwest for the next 12 to 24 hours before making a turn to the northwest Saturday, with another turn to the north-northwest Saturday night or Sunday. After crossing the Keys, Irma is expected to roll up the coast.
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