(NEXSTAR) – The view on land in Florida Thursday afternoon was overcast and stormy, but incoming Hurricane Helene looked even more ominous from space.

The storm was upgraded to a Category 3 as it barreled toward the Florida coast. It could be seen churning over the Gulf of Mexico and picking up steam in satellite videos taken by NOAA.

The bands of clouds stretching out from the hurricane’s eye are so vast, they obscure almost the entire Southeastern United States when seen from space.

Helene was expected to make landfall Thursday evening along Florida’s northwest coast. The National Weather Service office in Tallahassee forecast storm surges of up to 20 feet and warned they could be particularly “catastrophic and unsurvivable” in Apalachee Bay. It added that high winds and heavy rains also posed risks.

“You cannot survive 20 feet or even 15 feet of storm surge,” said Jeff Berardelli, chief meteorologist at NewsNation affiliate WFLA. “If you’re near the water and you know you’re going to flood, especially if you’re in a mobile home, too. You’ve got to go. You cannot take your chances. This is not survivable.”

The dangerous impacts of Helene could extend far beyond Florida. While the hurricane will likely weaken as it moves inland, damaging winds and heavy rain were expected to extend to the southern Appalachian Mountains, where landslides were possible, forecasters said.

For Atlanta, Helene could be the worst strike on a major Southern inland city in 35 years, said University of Georgia meteorology professor Marshall Shepherd.

The National Weather Service office in Greenville-Spartanburg, South Carolina, said record flooding was in the forecast that could rival the devastating flood of Asheville, North Carolina, in 1916.

“This will be one of the most significant weather events to happen in the western portions of the area in the modern era,” the local National Weather Service team said.

“This is a potentially historic event with catastrophic, deadly consequences. This is not a maybe. This is on track to happen. So please, please take every precaution to take yourself out of harm’s way,” said Taylor Jones, emergency services director in Buncombe County, North Carolina.

Lesser tropical storm warnings were issued as far north as North Carolina, and officials warned that much of the region could experience prolonged power outages and flooding.

The Associated Press contributed to this report.