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Hurricane Helene live updates: 43 dead in Florida, Georgia, South Carolina, North Carolina
Flash flood emergencies are ongoing in multiple 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 and is now post-tropical, but its remnants will continue to produce dangerous weather. The center of the storm is now over Kentucky with heavy rain and gusty winds across a large area from Missouri to Ohio to the Carolinas.
Latest headlines:
Extreme flash flooding possible in Blue Ridge Mountains in Georgia, Carolinas
Extreme flash flooding is possible in the Blue Ridge Mountains in Georgia, North Carolina and South Carolina.
First, a storm system separate from Helene is hitting the south on Wednesday. Up to 6 inches of rain is possible over the next 24 hours, bringing a flash flood risk from Atlanta to Asheville, North Carolina.
Then, Thursday afternoon through Friday morning, Hurricane Helene will bring even more extreme rain and flooding to the southern Appalachians.
A rare "high risk" alert for heavy rain has been issued. Up to 15 inches of rain is possible in some spots.
-ABC News’ Max Golembo
How storm surge works and why it’s so dangerous
Helene is forecast to bring 10 to 15 feet of dangerous storm surge to Florida’s Big Bend area, and 4 to 8 feet of storm surge to Tampa Bay.
In 2005, during Hurricane Katrina, at least 1,500 people died "directly, or indirectly, as a result of storm surge," according to the National Hurricane Center.
Click here to read how storm surge works and why it's so dangerous.
Helene nears hurricane strength
Tropical Storm Helene is nearing hurricane strength Wednesday morning as it churns just of the northeastern coast of the Yucatan Peninsula.
Helene is about 100 miles west-southwest from the western tip of Cuba.
-ABC News’ Max Golembo
Tropical storm forecast to 'rapidly' intensify into major hurricane
Tropical Storm Helene was expected to "rapidly" strengthen and grow in size as it moved on Wednesday into the Gulf of Mexico, U.S. weather officials said.
The storm as of about 4 a.m. local time had maximum sustained winds of about 65 mph, the National Hurricane Center said. It was expected to intensify into a hurricane on Wednesday, before further strengthening into a "major" hurricane on Thursday, the center said.
Helene early Wednesday was traveling northwest at about 9 mph, the center said.
"On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula this morning, move across the eastern Gulf of Mexico on later today and Thursday, and reach the Big Bend coast of Florida late Thursday," the center said.
-ABC News' Max Golembo and Kevin Shalvey