Helene is slamming Florida, Georgia and the Carolinas with torrential rain.
Helene -- which weakened to a tropical storm on Friday morning over Georgia -- made landfall as a massive Category 4 hurricane, slamming into the Big Bend region of Florida on Thursday night with 140 mph winds.
The monster storm churned across Florida into Georgia, leaving at least three people dead and millions without power across the Southeast. Significant flooding was reported across the region, with more rain expected Friday as Helene moves toward Tennessee.
The Tampa International Airport will close at 2 a.m. Thursday ahead of Hurricane Helene, officials said.
Airport officials expect to reopen Friday.
The St. Pete-Clearwater International Airport is also closing on Thursday and plans to reopen Friday.
Helene, currently a Category 1 hurricane, is expected to rapidly intensify and could reach major category status -- Category 3 -- by Thursday morning.
Helene could be a high-end Category 3 hurricane with 125 mph winds by the time it makes landfall Thursday night in the Big Bend area of Florida. Helene might even be a Category 4 hurricane with 130 mph winds during landfall.
A hurricane warning is in effect just north of Tampa, covering Apalachicola, Florida; Tallahassee, Florida; and Valdosta, Georgia.
A tropical storm warning is in effect in Jacksonville, Florida; Orlando, Florida; Miami; and Charleston, South Carolina.
Inland flash flooding is also a major concern.
A separate storm is bringing heavy rain to Georgia and the Carolinas on Wednesday, so the additional rain from Helene could cause a historic flood event in the southern Appalachians Thursday night into Friday.
A tropical storm watch has been extended further north to include Atlanta and Asheville, North Carolina, for Thursday night into Friday morning. Strong, damaging winds up to 70 mph are possible in Atlanta on Friday.
-ABC News’ Max Golembo
The University of Tampa is ordering all students who live on campus to evacuate by 1 p.m. Wednesday, citing mandatory evacuation orders from Hillsborough County officials.
Hurricane Helene is forecast to bring dangerous storm surge to the Tampa Bay area.
"The residence halls will be closed after the evacuation concludes, and there will be no entry allowed into residential buildings until they are reopened following the storm," the university said in a message to students.
The University of Tampa said it plans to resume operations on Monday.
-ABC News’ Alex Faul
Helene has strengthened to a Category 1 hurricane with sustained winds of 80 mph.
Helene -- now located about 500 miles south-southwest of Tampa, Florida -- is the fifth hurricane to form in the Atlantic Basin this season.
