Hurricane Irma strengthened to a Category 4 hurricane on Monday as it churned toward the Caribbean amid storm warnings, watches and states of emergency in Florida and Puerto Rico.
The hurricane, with its 130-mph winds, could become even more powerful in the next two days, just as it’s forecast to reach the U.S. Virgin Islands and Puerto Rico, the National Hurricane Center said Monday.
Irma “is moving into waters that are warmer and [are] a very favorable environment for even further development,” said Heather Tesch, a meteorologist for The Weather Channel.
The hurricane center’s forecast called for storm surges of 1 to 6 feet and rainfall totaling as much as 10 inches across the two islands.
Similar conditions were expected across the Leeward Islands, the center said, adding that Irma could also hit Cuba, the Dominican Republic, Haiti, the Bahamas and Florida later in the week.
Puerto Rico Gov. Ricardo Rossello declared a state of emergency on Monday, activating the National Guard, canceling schools and freeing up $15 million in emergency funds for the financially troubled island, his office said in a statement.
Related: Toll From Hurricane Harvey Includes Ongoing Trauma Felt by Survivors
In Florida, Gov. Rick Scott also declared an emergency, saying it was necessary for local governments to prepare immediately.
“Current forecast models have Florida in Irma’s path — potentially impacting millions of Floridians,” he said in a statement. “While the exact path of Irma is not absolutely known at this time, we cannot afford to not be prepared.”
Residents appeared to be listening.
Images posted to social media from Naples, in south Florida, and Temple Terrace, outside Tampa, showed bare store shelves.
“There’s a drought in the water aisle and Home Depot is packed,” NBC Miami reporter Ari Odzer joked on Twitter.
At a Home Depot in Royal Palm Beach, a sign alerted shoppers that it was short on wing nuts and 5-gallon jugs for gasoline and water.
A shopper there, David Graham, recalled Hurricane Harvey, the powerful storm that struck Texas’ Gulf Coast late last month. Tens of thousands of people fled to shelters, and thousands more were rescued. Forty-five deaths have been attributed to Harvey so far across six Texas counties.
“People are being more vigilant, I guess,” Graham told NBC affiliate WPTV of West Palm Beach.
Another shopper, Bianca Rodriguez, told the station that she’d earlier gone to Walmart, where was “nothing” — “not even, like, one thing of water,” she said. So she went to Winn-Dixie instead, where she found the cases of water she’d been searching for.
“I lucked out,” she said.