Tropical Storm Helene rapidly intensified Wednesday morning as it plows toward a Florida landfall as the strongest hurricane to hit the US in over a year.

The storm will also grow into a massive, sprawling monster as it intensifies that won’t just slam Florida, but also much of the Southeast.

Time is running out for those in the US to prepare. Thousands of Florida residents have already been forced to evacuate coastal areas and nearly the entire state is under tropical alerts as Helene threatens to unload flooding rainfall, damaging winds and life-threatening storm surge.

Helene is on track to make landfall on Florida’s Gulf Coast – possibly in the Big Bend region – late Thursday and threatens to become the strongest storm to hit the United States in over a year. Just 4 mph shy of becoming a hurricane Wednesday morning, Helene would be the fourth hurricane to make landfall in the US this year and the fifth to slam Florida since 2022.

The storm, which formed Tuesday morning in the northwestern Caribbean Sea, is strengthening at a breakneck pace. It could take Helene just 48 hours to go from a 45-mph tropical storm to a Category 3 major hurricane as it rapidly intensifies over the extremely warm waters of the Gulf of Mexico. As of 8 a.m. ET, Helene’s maximum sustained winds had increased to 70 mph with higher gusts, the center said.

A flood watch has been issued for more than 20 million people from Florida through the southern Appalachians, with tornadoes a risk through Friday across the region.

The Big Bend area faces the most serious storm surge: up to 15 feet of it is possible.

“If you’re a godly person, pray, because I don’t really need this,” Port Richey resident Rick Way told CNN affiliate WFTS of the potential flooding Helene could bring. “Neither do any of us.”

Helene comes as Florida’s Big Bend region is still recovering from several recent hurricanes. Hurricane Debby slammed the region in early August as a Category 1 storm and recovery efforts are still ongoing as the region braces for another blow. Idalia – the last hurricane to make landfall in the US at Category 3 – also came ashore in the Big Bend region in August last year and generated a record-breaking storm surge from Tampa to the Big Bend.

Way said he would spend Tuesday afternoon sandbagging around his home, in an area flooded by Idalia last year.

“You see the proximity of where we are to the water. There are other people across the street and elsewhere on this street that got a foot to 3 feet of water,” Way told WFTS. “It didn’t matter whether it was 3 feet or 6 inches. It still got us.”

A hurricane warning was issued for parts of Florida’s Gulf Coast, from Anclote River to Mexico Beach, according to the National Hurricane Center’s 11 p.m. ET advisory. The Mexican government has also issued a hurricane warning from Cabo Catoche to Tulum.

Evacuations began Tuesday for some coastal areas of Florida facing potentially dangerous storm surge. Officials ordered mandatory evacuations in parts of at least nine counties, including Citrus, Hillsborough, Charlotte, Gulf, Manatee and Pinellas.

In Taylor County, just southeast of Tallahassee, the sheriff’s office issued a mandatory evacuation order Tuesday evening for all residents and placed a curfew in effect from sunrise to sunset, according to a statement. “This system will be unlike anything we have experienced to date,” the sheriff’s office said. Mandatory evacuations have also been ordered for the entirety of Franklin and Wakulla counties.

The wider Southeast is bracing for potentially large and powerful impacts, too. Torrential rain, strong winds capable of causing significant power outages and the threat of tornadoes will stretch into the region.

The storm is expected to still be a hurricane when it moves into south Georgia early Friday.

Considerable and potentially life-threatening flash and urban flooding is expected across portions of the Southeast, the southern Appalachians, and the Tennessee Valley beginning Wednesday through Friday, including the risk of landslides across the southern Appalachians. Widespread minor to moderate river flooding is likely, and isolated major river flooding is possible.

There could also be shifts in the storm’s track in the coming days, the National Hurricane Center warned, and that could alter where its worst impacts occur.

Floridians are bracing for Helene after recovering from Idalia and Ian

Just over a year ago, some Florida residents’ homes were in shambles after Hurricane Idalia hit the state. Now they’re bracing for another potentially destructive storm.

“If you don’t do something, you’re going to get it,” Howard Rabe told CNN affiliate WFTS. “We’ve been through a lot of these in all the years we’ve been here.”

His home in Port Richey is in the same area that flooded after Idalia last August. Ahead of Helene, Rabe pulled out hurricane shutters and flood barriers on Tuesday to protect his home.

Over in Sanibel, one couple who met during Hurricane Ian in 2022 and nearly lost everything are now going to weather Helene together, CNN affiliate WINK reported.

Before Ian, Michele Vikartofsky and Larry Leventhal were strangers.

“We both were crazy people that stayed. We were neighbors. We had not met. We just met during the hurricane, spent two days walking around after, and now this happened, so Ian brought us together,” Vikartofsky said.

This time around, they feel a lot less concerned, the couple said.

“After living through Ian, it’s like you could get through anything,” Vikartofsky said.

“Ian was destructive. Ian taught us all a lesson that we never thought would happen here. Storm surge is always predicted, but (it) never happened like Ian, so, yeah, we’ve learned to watch a little bit, be a little bit more careful,” Vikartofsky said.

In a group chat with their neighbors, the couple discusses what they’ll do about their vehicles and transportation if there’s bad flooding in their area, Vikartofsky told WINK.

Another family in Manatee County is still dealing with the damage left behind by Hurricane Debby in August.

“Overwhelmed. Just too much for us. We’re 84. At that age, it’s hard to handle,” Ron Booher told CNN affiliate WFTV.

In Gulf County, one resident and business owner said she’s preparing for the worst-case scenario.

“You start worrying because during Hurricane Michael my house was destroyed. The four businesses were destroyed. I worked for the Port Inn and it was destroyed,” Lynn Marshall told CNN affiliate WJHG.

Florida and Georgia governors issue emergency declarations

Florida Gov. Ron DeSantis expanded an emergency declaration from 41 to 61 of the state’s 67 counties Tuesday over the threat of more inland impacts. The declaration helps expedite preparations and coordination between the state and local governments ahead of the storm’s arrival.

At least 3,000 members of the Florida National Guard are ready to assist with storm efforts and the Florida State Guard has been activated, DeSantis confirmed at a news conference Tuesday. Additionally, the state has “hundreds of Starlinks” to deploy in case internet access is lost, according to DeSantis.

The storm’s large size and intensity could also drive up to 8 feet of surge in the greater Tampa area and feet of surge in areas farther south. With little time to prepare, Tampa General Hospital began erecting a 10-foot-high flood barrier around the facility Monday because of the storm surge risk.

Officials in neighboring Pinellas County warned hundreds of homes would likely flood with a higher storm surge than in past destructive storms.

“This storm is much larger than Idalia and Eta, and for Idalia, portions of our county had over 4 feet of storm surge and we had over 1,500 homes flooded,” Pinellas County emergency management director Cathie Perkins said in a Tuesday news conference. “If you experienced flooding for Eta and Idalia and the Christmas storm we had, you’re most likely going to have flooding in your area again.”

The repeated blows have pushed Florida’s insurance market to the brink, with insurers pulling out of the state because of the increasing risk of extreme weather due to climate change.

A mandatory evacuation order was issued for all residential health care facilities along the coast of St. Petersburg, Florida, as residents brace for Helene, according to Mayor Kenneth Welch, with more evacuation orders expected as the storm nears.

“This is a powerful storm, and the time to prepare is now,” Welch said at a news conference. The mayor also requested residents restrict water use in the coming days to help prepare for storm surge as high as 5 to 8 feet in the area.

Several school districts along Florida’s Gulf Coast – including those in Hillsborough, Pinellas and Sarasota counties – have announced closures ahead of the storm’s impacts. Several of the state’s universities have also announced closures.

Georgia Gov. Brian Kemp also declared a state of emergency due to the storm’s expected impacts later this week.

“As we monitor Tropical Storm Helene’s path and potential impact, I have declared a State of Emergency enabling emergency management teams to prepare for and direct resources well in advance of the storm’s arrival. Stay vigilant and stay safe,” Kemp said on X.

Georgia officials warned residents to prepare for a wind event that will affect all 159 counties throughout the state.

“The old saying in emergency response is – you run from water, you hide from wind,” Georgia Emergency Management and Homeland Security Agency Director James Stallings said in a news conference Tuesday, adding people should ensure their emergency supplies will enable them to be safe for up to 72 hours in case power or water goes out.

Southeast could feel tropical storm-force winds and heavy rainfall starting midweek

As early as Wednesday afternoon, tropical storm-force wind gusts could begin for the Florida Keys and spread northward, reaching much of the Peninsula by Thursday morning at the earliest. Hurricane-force wind gusts could follow closely behind for many coastal areas.

Starting late Wednesday night, the worst wind and rain could hit the Tampa area. It won’t let up through Thursday evening, with hurricane-force winds possible, according to the National Weather Service in Tampa Bay.

Landfall is expected southeast of Tallahassee late Thursday, but the worst conditions will arrive in the city earlier and last throughout the day.

By Thursday evening, tropical storm-force winds will spread over more of the Southeast and, along with soaking rainfall, could bring down trees and trigger widespread power outages.

For much of the Southeast, heavy rainfall is possible starting around midweek, but the most torrential rain will fall Thursday into Friday morning. A level 3 of 4 risk of flooding rain is in place for parts of Florida, Georgia, Alabama and parts of the Carolinas Thursday, according to the Weather Prediction Center.

Widespread rainfall totals of 4 to 8 inches are expected from Florida’s Gulf Coast into parts of Tennessee, the Carolinas and Virginia. Totals could approach a foot in parts of the Florida Panhandle and the southern Appalachians. Much of this rain will fall by Friday for the Gulf Coast, but it’ll be a wet weekend farther north.

This rainfall will occur ahead of a slow-moving cold front fed by deep tropical moisture streaming in from Helene. It’s a set-up known as a predecessor rain event: heavy rain that occurs several hundred miles to the north of a tropical cyclone. These events can often lead to significant flash flooding, and the weather prediction center also warned mudslides and landslides could occur in the southern Appalachians.

In this case, 2 to 4 inches of rainfall is expected Wednesday into Thursday, from northern Alabama and Georgia northward into eastern Tennessee and western portions of the Carolinas, well before Helene makes landfall in Florida.