(NEW YORK) -- Water levels were rising along South Carolina's coast early Thursday morning as Hurricane Dorian inched toward the picturesque port city of Charleston.
Charleston residents who didn't heed earlier evacuation orders have now been asked to shelter in place as the winds pick up and heavy rain falls down. Downtown Charleston's narrow, low-lying streets are underwater and the northbound portion of the city's expressway has been shut down since Wednesday due to flooding.
Authorities were deployed throughout the city overnight responding to calls of downed trees and power lines, floods and other storm-related incidents, according to the Charleston Police Department.
Meanwhile, more than 201,000 homes and businesses were already without power across South Carolina as of Thursday morning.
The Charleston County Sheriff's Office took to Twitter early Thursday to urge lingering residents to "not leave your home unless your life is in danger there."
"Don’t put your life on the line," the sheriff's office tweeted.
Hurricane Dorian, which restrengthened back to a Category 3 late Wednesday packing sustained winds of 115 miles per hour, is forecast to come very close to South Carolina's shores later Thursday morning, with Charleston and Myrtle Beach expected to bear the brunt of the impact.
Dorian is then forecast to move near or over the coast of North Carolina around Thursday night through Friday morning, during which time the storm will likely make landfall somewhere along the state's barrier islands, the Outer Banks, according to the National Hurricane Center.
The coastal Carolinas are expected to get up to 12 inches of total rainfall through Friday, with as much as 15 inches accumulating in isolated locations. Coastal Georgia and far southeast Virginia could see as much as 6 inches, according to the National Hurricane Center.
The combination of relentless rain and a dangerous storm surge of up to 8 feet could cause life-threatening flash floods in some areas, depending on how close the eye of the storm comes to shore.
A flash flood warning has been issued for Charleston, where more than 4 inches of rain have fallen since Wednesday. The coastal city is expected to see 1 to 2 inches of rain per hour throughout Thursday.
Meanwhile, a tornado watch and warning are in effect in and around the Myrtle Beach area. The tornado watch also stretches across state lines to Wilmington, North Carolina.
A tornado was spotted early Thursday morning near a highway in Little River, South Carolina, some 25 miles northeast of Myrtle Beach, while another touched down in North Myrtle Beach. A tornado was also observed in Columbus, North Carolina, according to the National Oceanic and Atmospheric Administration's Storm Prediction Center.
"It is not that uncommon to see tornadoes with a tropical system near the coastline," said ABC News senior meteorologist Max Golembo.
One storm-related death has already happened in North Carolina. An 85-year-old man fell off a ladder while preparing his Columbus County home for Dorian, North Carolina Gov. Roy Cooper announced Wednesday.
So far, the eye of the storm has moved parallel to -- but remained offshore of -- the southeastern United States. But hurricane-force winds extend outward up to 60 miles from the center, while tropical-storm-force winds extend as much as 195 miles. After lashing Florida's east coast Wednesday with heavy rain and strong winds, Dorian's outer bands were striking seaside communities from Georgia to southern North Carolina on Thursday morning, according to the National Hurricane Center.
More than 4,000 flights have been cancelled within, into or out of the United States since Monday. A number of airports have shuttered this week, including several in Florida, two in South Carolina and one in North Carolina.
Before approaching the United States, Dorian slammed into the Bahamas on Sunday afternoon as a Category 5 hurricane, the strongest Atlantic hurricane landfall on record. The storm hovered over the archipelago's northern islands for nearly two days, leveling dozens of buildings, flooding roads and submerging an airport. The official death toll from the storm is now at 20 but that number is expected to rise further in the coming days as authorities assess the destruction on the ground, according to Bahamian authorities.
The Bahamas Prime Minister Hubert Minnis said at a press conference Wednesday that Dorian has left "generational devastation" across the Abaco Islands and Grand Bahama, which are both in the archipelago's northern region, east of southern Florida.
Princess Margaret Hospital in Nassau, the capital of the Bahamas, is now the only hospital capable of treating the most seriously injured from across the 700-plus islands and cays, according to Dr. Caroline Burnett-Garraway, medical chief-of-staff at the hospital.
Burnett-Garraway said the hospital has received at least 38 patients, including children, who were medically evacuated from hard-hit islands. Many were subjected to floodwaters and intense winds for days. Their injuries range from severe dehydration to lacerations and broken bones to acute kidney injuries. One patient had to have his upper arm amputated, she said.
“A whole family was in a car and a roof blew off and fell into their car. A 7-year-old is badly hurt. The family was taking shelter from the storm," Burnett-Garraway told ABC News, recalling some of the patients they have treated thus far.
Storm conditions have made it difficult to evacuate patients. Three men died immediately after arriving at Princess Margaret Hospital, according to Burnett-Garraway.
"We have to forge on," she said, "day by day."
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