Helene strengthened into a hurricane on Wednesday as forecasters warned it could become a major Category 3 storm before it makes landfall along Florida's Gulf Coast late Thursday.

The storm is expected to bring "life-threatening storm surge, damaging winds and flooding rains" to a large portion of Florida and the Southeast, the National Hurricane Center warned.

A state of emergency has already been declared in Florida, where evacuations for people in low-lying areas are underway. Residents in the storm's potential path have been told to prepare for up to a week without electricity.

"It's a big, big storm," Florida Gov. Ron DeSantis said at a press briefing Wednesday. "Many people will lose power ... be prepared for that."

Where is the storm and what is its path?

According to the National Hurricane Center's latest advisory, Helene — with maximum sustained winds of 80 mph — is located about 85 miles east-northeast of Cozumel, Mexico, and 500 miles south-southwest of Tampa, Fla., and is moving north-northwest at 10 mph.

The storm is expected to rapidly intensify and come ashore along the Gulf Coast of Florida as a Category 3 storm, with maximum sustained winds exceeding 111 miles per hour.

"Damaging hurricane-force winds are expected along portions of the coast of the Florida Big Bend, where a Hurricane Warning is now in effect," the hurricane center said. "Preparations to protect life and property should be complete by early Thursday."

In addition to high winds, the storm will threaten millions of residents along the Gulf Coast with up to 12 inches of rainfall, as well as the possibility of tornadoes. Before it heads up into the Gulf of Mexico, Helene will bring heavy rain to portions of the western Caribbean, potentially mudslides and flooding across western Cuba. The system will also pose the threat of inland flooding across several U.S. states.

"Considerable flash and urban flooding is expected across portions of Florida, the Southeast, southern Appalachians, and the Tennessee Valley Wednesday through Friday," the National Hurricane Center said.

There is the potential for life-threatening storm surge along the entire Florida peninsula, the weather service warned.

How is Florida preparing?

DeSantis expanded a state of emergency on Tuesday to 61 counties ahead of the storm. Helene is expected to make landfall near the Big Bend region of the Florida panhandle, which was pummeled by Hurricane Debby earlier this season.

The declaration allows the state to execute its Comprehensive Emergency Management plan, allowing the use of resources for any logistical, rescue or evacuation operations.

"Now is the time to make an emergency plan, know your evacuation zone, and be as prepared as possible for the storm," DeSantis said in a post on X.

Watches and warnings

As of 11 a.m. ET on Wednesday, a hurricane warning was in effect for:

Anclote River to Mexico Beach, Florida

Cabo Catoche to Tulum, Mexico

A "hurricane warning" means that hurricane conditions are expected somewhere within the warning area. It is typically issued 36 hours before the anticipated arrival of tropical-storm-force winds.

A hurricane watch was in effect for:

Pinar del Río Province, Cuba

Englewood to Anclote River, including Tampa Bay

A "hurricane watch" means hurricane conditions are possible within the watch areas. It is usually issued 48 hours before the hurricane is anticipated to hit.

A tropical storm warning was in effect for:

Dry Tortugas

All of the Florida Keys

The west coast of Florida from Flamingo to Anclote River, including Tampa Bay

West of Mexico Beach to the Okaloosa/Walton County Line

The east coast Florida from Flamingo north to South Santee River

Lake Okeechobee

Rio Lagartos to Tulum, Mexico

Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth

A "tropical storm warning" means that tropical storm conditions are expected in the warning areas within the next 36 hours.

A tropical storm watch was in effect for:

The coast of South Carolina north of South Santee River to Little River Inlet

A "tropical storm watch" means that tropical storm conditions are possible within the watch area.

A storm surge watch was in effect for:

Indian Pass, southward to Flamingo

Tampa Bay

Charlotte Harbor

A "storm surge watch" indicates the possibility of life-threatening flooding, such as rising water moving inland from the coast.