Tropical Storm Ian is expected to become a hurricane Sunday night and reach major hurricane strength early next week, forecasters said.
The storm, currently in the Caribbean Sea with maximum sustained winds near 50 mph and higher gusts, is expected to become a major hurricane — meaning a Category 3 — by Monday or Tuesday, forecasters said.
The storm is 540 miles southeast of the western tip of Cuba and could approach the Florida Keys and the southern and central area of the Florida peninsula beginning Monday through to Wednesday morning, according to the National Hurricane Center.
The potential hurricane is forecast to bring 2 to 6 inches of rain to the Keys and peninsula, and even bring heavy rainfall to northern and western Florida, as well as to other states in the southeastern U.S. on Thursday, Friday and Saturday.
These rains may produce flash and urban flooding across the Keys and the peninsula through midweek.
Flooding and rising in streams and rivers in northern Florida and parts of the southeast U.S. later in the week "cannot be ruled out," according to forecasters.
President Joe Biden on Saturday approved an emergency declaration for Florida as the state faces a potential major hurricane from the current storm, the White House said.
“Regardless of Ian’s exact track, there is a risk of dangerous storm surge, hurricane-force winds, and heavy rainfall along the west coast of Florida and the Florida Panhandle by the middle of next week,” the weather agency said in a forecast discussion.
Gov. Ron DeSantis on Friday declared a state of emergency for 24 counties when the system was a tropical depression.
On Saturday, the governor expanded that to apply statewide, citing the risk of a major hurricane making landfall on Florida’s western coast.
Biden's approval of a Florida emergency declaration orders authorized federal aid.
Biden also postponed a Florida trip scheduled for Tuesday because of the storm, the White House said Saturday. The president had planned to go to Fort Lauderdale and then to a Democratic National Committee rally in Orlando. The DNC said the rally had been postponed.
Before the storm gets close to Florida, it is predicted to become a hurricane and pass near or west of the Cayman Islands, south of Cuba, early Monday, the hurricane center said. It will then move near or over western Cuba, where significant wind and storm surge impacts are expected, Monday night and early Tuesday before moving over to the southeastern Gulf of Mexico.
Western Cuba can receive anywhere from 6 to 16 inches of rain, while Jamaica and the Cayman Islands might receive 3 to 8 inches, according to forecasters. This rainfall may produce flash flooding and mudslides in higher terrain areas in Jamaica and Cuba.
Water levels along the coast of western Cuba can rise as much as 9 to 14 feet above normal tide levels Monday night and early Tuesday.
A hurricane warning is in place for Grand Cayman and the Cuban provinces of Isla de Juventud, Pinar del Rio and Artemisa. A tropical storm warning is in effect for the Cuban provinces of La Habana, Mayabeque and Matanzas while tropical storm watches are in place for Little Cayman and Cayman Brac.
Cayman Islands Premier Wayne Panton urged residents to get ready for the storm and to also check in on neighbors.
He said that there was some uncertainty, but that “history has taught us that we must prepare as best we can, and we must prepare for the worst and absolutely pray and hope for the best.”
Ian will move near or over western Cuba late Monday before getting into the Gulf of Mexico, the hurricane center said. Cuba could get up to a foot of rain and the Cayman Islands could see up to 10 inches in some areas.
The center of the storm was about 430 miles southeast of Grand Cayman at 8 p.m. ET Saturday, according to the hurricane center. It was moving west at 14 mph but was predicted to turn northwest Sunday and Monday, it said.
The Atlantic hurricane season begins on June 1 and ends on Nov. 30, and so far it had been relatively quiet for southern Florida.
“I thought we were going to be OK this year because it is pretty far into the season, but it looks like one snuck up on us,” Pamela Shook of Bonita Springs, south of Fort Myers, told NBC affiliate WBBH.
Bonita Springs was among the communities that suffered flooding and other impacts from Hurricane Irma in 2017, which struck the Florida Keys as a Category 4 and Southwestern Florida as a Category 3 storm.
It caused widespread devastation. Ten people died in the U.S. directly from the storms, and there were 82 “indirect” deaths, most of which were in Florida, according to a National Hurricane Center report.
This article was originally published on NBCNews.com