By Devika Krishna Kumar and Catherine Koppel

Some parts of the Gulf Coast have already been inundated with more than 18 inches (46 cm) of rain in the last 24 hours, with more precipitation expected even as the storm’s winds slow, the National Hurricane Center said.

Pensacola, Florida, a coastal resort community of 50,000, suffered up to five feet of flooding and travel was cut by damaged roads and bridges. More than 500,000 homes and businesses across the area were without power as the storm knocked over stately oak trees and tore power lines from poles.

The storm was moving at a slow 5 mile-per-hour (8 km-per-hour) pace toward the Alabama-Florida border.

“The rain is what stands out with this one. It’s unreal,” said Cavin Hollyhand, 50, who left his home on a barrier island and took shelter in Mobile, Alabama, where he viewed the damage on Wednesday.

Upon landfall at Gulf Shores, Alabama, Sally’s winds were clocked at 105 mph (165 kph). Along the coast, piers were ripped away by the storm surge and winds.

Alabama Governor Kay Ivey, in a message on Twitter, told residents not to go outside to check on damage unless necessary, and to stay away from live power lines and fallen trees.

“We had strong winds for a long period of time. Instead of a few hours we got it for 12 hours,” said 38-year-old Grant Saltz as he took a break from clearing debris outside his Mobile restaurant.

In Pensacola, wind gusts were clocked at 77 mph (125 kph) on Wednesday, and images on social media showed major floods. One witness reported hailstorms in the city as well and the NHC warned of possible tornados.

City police in Pensacola told residents on Twitter not to drive around looking at damage due to high winds.

“We see lots of ‘lookers’ out. It’s slowing our progress down. Please stay at home!,” the department tweeted.

Sally is the 18th named storm in the Atlantic this year and the eighth of tropical storm or hurricane strength to hit the United States. There are three named storms in the Atlantic, none now threatening the United States.

“We’ve only got one name left,” said Jim Foerster, chief meteorologist at DTN, an energy, agriculture and weather data provider, referencing the procedure to name storms. “That’s going to happen here soon, Wilfred, and then we’ll be into the Greek alphabet.”

Damage from Sally is expected to reach $2 billion to $3 billion, said Chuck Watson of Enki Research, which tracks tropical storms and models the cost of their damage. That estimate could rise if the heaviest rainfall happens over land, Watson said.

As the storm moved east and inland, ports on the western Gulf Coast were reopened to travel and energy companies were beginning to return crews to offshore oil platforms.

Sally shut more than a quarter of U.S. Gulf of Mexico offshore oil and gas production. Two coastal oil refiners halted or slowed operations, adding to existing outages from last month’s Hurricane Laura and pandemic-related demand losses. (Reporting by Devika Krishna-Kumar and Catherine Koppel in Mobile, Alabama; additional reporting by Jennifer Hiller in Houston and Stephanie Kelly and Scott DiSavino in New York; Editing by Chizu Nomiyama, Nick Zieminski, Jonathan Oatis and Steve Orlofsky)