Tropical Storm Ian was forecast to rapidly gain strength Sunday while racing across the Caribbean toward Cuba and threatening a big hit to Florida’s west coast later in the week.

Ian was 430 miles southeast of Cuba Sunday evening, cruising northwest at 13 miles an hour with 65 mph winds. The storm was forecast to reach hurricane status late Sunday or early Monday, then roll across western Cuba Monday night and early Tuesday.

As Ian approaches Florida, Accuweather said the storm could reach Category 4 status, which means sustained winds between 130 mph and 156 mph.

“In just a few days, Ian is likely to be a dangerous, major hurricane,” AccuWeather Senior Meteorologist Adam Douty said.

Florida Gov. Ron DeSantis urged residents to load up on food, water, medicine, batteries and fuel. He said it was too soon to determine when or even if Ian will make landfall, but that evacuations may be ordered in coming days.

“Expect heavy rains, strong winds, flash flooding, storm surge and even isolated tornadoes. Make preparations now,” he said Sunday. “Anticipate power outages. That is something that is likely to happen with a hurricane of this magnitude.”

The National Hurricane Center issued a tropical storm watch for the lower Florida Keys Sunday.

“Significant” wind and storm surge damage was expected across a wide swath of the Atlantic Basin, and the Cuban government upgraded the hurricane watch to warning.

Such storms can cause “catastrophic” damage, with power outages that can last weeks or possibly months, according to the National Weather Service description. Areas can be uninhabitable for weeks or months, the weather service says. 

“Even if you’re not necessarily right in the eye of the path of the storm, there’s going to be pretty broad impacts throughout the state,” DeSantis said.