Flash flood emergencies are in effect in five states.
Helene made landfall in Florida's Big Bend region Thursday night as a massive Category 4 hurricane -- the strongest hurricane to make landfall in the Big Bend on record.
Helene has since weakened to a tropical storm and is now pushing through Georgia and the Carolinas, bringing catastrophic rainfall and life-threatening flash flooding as the storm moves toward Tennessee.
The Hillsborough County Sheriff’s Office in Tampa, Florida, released dramatic video showing the moment one of its deputies rescued a teenage girl who was trapped in her car in rising floodwaters. The deputy lifted her out of her car and drove her to safety.
Mandatory evacuations are in place for some residents of Asheville in western North Carolina as severe flooding from Hurricane Helene hits the state.
North Carolina faces flooding emergency
Evacuations were ordered for the Swannanoa River Valley area due to a high risk of flooding from the "catastrophic rain," officials said.
Parts of the state have recorded up to 15 inches of rain, with more expected through Friday. Some areas are expecting as much as 20 inches of rain through the course of the storm. Dangerous landslides are also expected.
Water rescues and flooded homes have been reported in Haywood County, just west of Asheville.
-ABC News’ Max Golembo
About 200 people have been rescued overnight from the rising floodwaters in Pasco County, Florida, just north of Tampa, according to the Pasco Sheriff’s Office.
The water is receding Friday morning and rescue calls have slowed, authorities said.
Hurricane Helene was downgraded to a tropical storm around 100 miles southeast of Atlanta early on Friday, as its sustained wind speed slowed to 70 mph.
Life-threatening winds, flash flooding, rain and storm surge are ongoing through Florida, Georgia, North Carolina and South Carolina.
Helene is expected to slow and weaken as it travels north-northwest through Georgia toward the Tennessee-North Carolina border, the National Hurricane Center said.
Helene is projected to turn post-tropical on Friday afternoon or Friday night, the NHC said.
"However, the fast forward speed will allow strong, damaging winds, especially in gusts, to penetrate well inland across the southeastern United States, including over the higher terrain of the southern Appalachians," the NHC said.
-ABC News' Max Golembo
