Less than two weeks after Hurricane Harvey devastated parts of Texas and Louisiana, another "potentially catastrophic" storm was bearing down on the northeastern Caribbean and could threaten Florida later in the week, the National Hurricane Center said Tuesday.
Hurricane Irma had strengthened into a Category 5 storm, one of the most powerful ever recorded over the Atlantic Ocean, with maximum winds close to 185 mph, according to the weather service in Miami. Three other storms have matched Irma's ferocity, but only Hurricane Allen in 1980 was more intense, with winds peaking at 190 mph.
Irma was expected to remain a Category 4 or 5 storm for days as it barrels through the Caribbean, bringing life-threatening wind, rain and storm surges Wednesday to some of the northern Leeward Islands, including the U.S. and British Virgin Islands and Puerto Rico.
If the storm remains on its current path, it could reach the Florida Straits by the weekend.
Although it was too soon to forecast its impact on the continental United States, meteorologists said it was increasingly likely that effects would be felt in the Florida Keys — a major tourist destination — and portions of the Florida peninsula.
"Everyone in hurricane-prone areas should ensure that they have their hurricane plan in place," the National Hurricane Center said in a statement.
States of emergency were declared in Florida, Puerto Rico and the U.S. Virgin Islands. President Trump also approved emergency declarations authorizing the Federal Emergency Management Agency to coordinate relief efforts in those places.
With Texas still reeling from Hurricane Harvey, which brought record-shattering rain and was blamed for at least 60 deaths, officials urged residents to prepare for the worst.
"The decisions that we make in the next couple of hours can make the difference between life and death," Puerto Rico Gov. Ricardo Rossello was quoted as saying by the Associated Press. "This is an extremely dangerous storm."
Residents scrambled to get out of flood zones, and customers emptied store shelves of food and water on some islands.
Florida Gov. Rick Scott activated 100 members of the National Guard, directing all 7,000 members to report for duty on Friday, and suspended all tolls on the state's freeways until further notice.
"With Hurricane Irma now a Category 5 storm, we must do all we can to prepare our families and communities for any potential impact from this major weather event," Scott told reporters in Naples, Fla. "While we hope for the best, we must prepare for the worst."
In Monroe County, where the Florida Keys are located, officials said they would be issuing mandatory evacuation orders for Wednesday, but urged tourists and residents not to wait and risk getting stuck in traffic.
"My wife is leaving the Keys today; she would rather go to the dentist than sit in traffic," said Martin Senterfitt, the Monroe County emergency management director. "The sooner people leave the better. If ever there was a storm to take serious in the Keys, this is it."
Evacuation orders could also be issued for Miami-Dade County, Florida's largest, on Wednesday or Thursday, officials said.
Schools canceled classes in both counties Wednesday and the Key West International Airport was scheduled to will close in the evening.
Residents from Tallahassee to Miami heeded the official calls to get ready, swarming gas stations, grocery stores and hardware outlets.
In St. Petersburg, on Florida's Gulf Coast, residents jammed a Home Depot, carting out sheets of plywood and other supplies to protect their windows.
Russell Arsenault, a self-employed tradesman, emerged from the store loaded with a stack of plywood and solar boards. He and his family had already been to a grocery store to stock up on water, canned goods, flashlights and batteries.
"After seeing what happened in Texas, and what they went through, we're trying to take all the precautions we can," Arsenault said in the parking lot. "I think the governor's made the right call considering what may happen. The idea of 170-mph winds scares the hell out of me."
Over in Wesley Chapel, a suburb of Tampa, a soldier-turned-lawyer, Gary de Pury, said he too believed in being prepared.
"There are hourlong lines at the Sam's Club here just for basics like water and fuel," De Pury said by phone. "With water already sold out and gas priced at $2.59 a gallon because of Hurricane Harvey, if you waited until today to prepare for Irma, it's already too late."
Irma was forecast to bring 8 to 10 inches of rain to the northern Leeward Islands, including Antigua and Barbuda, and 4 to 10 inches to both Puerto Rico and the Virgin Islands.
But authorities said storm surges — which could be as high as 20 feet on some islands — posed an even bigger threat to the Caribbean's coastal zones.
Officials in Puerto Rico warned that the island's electrical grid and other vital infrastructure were unlikely to withstand the storm's powerful winds. Some areas could be plunged into darkness for weeks, if not months.
The nearby island of Hispaniola, home to the Dominican Republic and Haiti, could also feel Irma's effects later in the week, along with Turks and Caicos Islands, Cuba and others, forecasters said.
Meanwhile, the U.S. hurricane center announced that a new tropical storm had formed over the central Atlantic on Tuesday. Tropical Storm Jose was expected to become a hurricane by Friday.
Special correspondent Neuhaus reported from St. Petersburg and Times staff writer Zavis reported from Los Angeles.
8:50 p.m.: This article was updated with Irma now expected to make landfall early Wednesday.
6:50 p.m.: This article was updated with President Trump declaring emergencies in Florida, Puerto Rico and the U.S. Virgin Islands and other details.
3:30 p.m.: This article was updated with officials preparing mandatory evacuation orders for the Florida Keys, comment from the governor of Puerto Rico and other details.
11:25 a.m.: This article was updated with information about the storm's path, a state of emergency declared in Florida and other details.