Ian has become a post-tropical cyclone, but winds remain at 70 mph and the "dangerous storm surge, flash flooding and high wind threat continues," the National Hurricane Center said in its latest bulletin.

Hurricane warning and watch areas have now been discontinued, though a tropical storm warning has been issued from Edisto Beach, South Carolina, to Cape Fear, North Carolina.

Floridian Hanna-Kay Williams started to experience contractions late Tuesday evening, just as the Orlando area was experiencing signs of the hurricane to come.

So she braved the strong winds and potentially dangerous flooding to get to a hospital after she went into labor during Hurricane Ian.

"I was going in and out because the car was swaying in the wind and the rain was intense, but my fiancé is a great driver so I was in great hands," Williams, 22, of Melbourne, told ABC News.

Read more about the account here.

-ABC News' Mary Kekatos

Hurricane Ian made landfall in South Carolina Friday afternoon as a powerful Category 1 storm, bringing damaging winds and life-threatening storm surge.

Ian made landfall near Georgetown. The storm is expected to move further inland across eastern South Carolina and central North Carolina through the night and into Saturday.

After making landfall, it is expected to weaken and rapidly transition into a post-tropical cyclone overnight. It is forecast to bring heavy rain to North Carolina and Virginia and up through the Northeast on Saturday.

Rainfall rates have been up to 2 inches per hour with heavy rain bands in the Charleston area. Wind gusts up to 92 mph have been recorded.

President Joe Biden spoke from the White House Friday afternoon about Hurricane Ian's wrath, describing the devastation in Florida as well as warning residents of South Carolina to be prepared for another landfall.

"We're just beginning to see the scale of that destruction," Biden said of the damage in Florida. "It is likely to rank among the worst in the nation's history. You have all seen on television, homes and property wiped out. It is going to take months, years to rebuild."

He added, "I just want the people of Florida to know we see what you are going through and we are with you. And we are going to do everything we can for you."

Biden said the U.S. Coast Guard has mobilized 16 helicopters, 18 rescue boats and six fixed-wing planes to help in search and rescue in Florida. More than 100 people have been rescued by the Coast Guard, Biden said. Hundreds more have been rescued by volunteers.

"The federal government will cover every cost, 100% of the cost, to clear the massive debris left in the wake of the hurricane and these counties," the president said. "It all needs to be cleared out for communities to begin the hard work of trying to get back on their feet."

Tropical Storm Ian has weakened slightly, but it is expected to not only strengthen but rapidly intensify overnight as it travels over warm waters in the Caribbean.

As of 5 p.m. ET, the storm system had maximum sustained winds of 45 mph and was moving west-northwest at 12 mph, with the center located about 220 miles away from Grand Cayman.

Dry air ahead of the storm has delayed the strengthening trend so far. But the rapid intensification is expected to occur Monday into Tuesday as the system continues across the northwestern Caribbean and closes in on western Cuba.

Over the next 24 hours, the outer bands will impact Jamaica and the Cayman Islands, bringing rounds of heavy rain, possible flash flooding and storm surge. Later Monday and into Monday night, Ian will be closing in on western Cuba and will likely bring significant wind and storm surge impacts to the region.

A hurricane warning is in effect for Grand Cayman and portions of western Cuba. A tropical storm watch has been issued for portions of western Cuba, as well as the lower Florida Keys, including Key West.

As of 5 p.m., the forecast track was nudged slightly eastward. Overall, the forecast guidance variability and uncertainty will remain high, and the track for where the storm will be from the middle to the end of the week will continue to shift over the next 24 to 48 hours.

-ABC News' Dan Peck