(RNN) - People in areas vulnerable to a dangerous hurricane have left or are fleeing ahead of the storm's expected Friday or Saturday landfall.
As of 5 a.m. ET, Hurricane Florence was 575 miles southeast of Cape Fear, NC, packing maximum-sustained winds of 130 mph and moving to the west-northwest at 17 mph, the National Hurricane Center in Miami reported.
The forecast track changed slightly overnight.
Forecasters expect Florence to slow down considerably by late Thursday as it encounters a mid-level ridge that is building over the eastern and central U.S. Because of this, the storm may move southwestward toward the South Carolina coast. Because of the shear, the hurricane may weaken before landfall but will still be a dangerous storm.
Wherever the storm eventually will make landfall, serious and dangerous conditions will extend far beyond the eye.
A storm surge warning has been issued from South Santee River, SC, to Duck, NC, and the Albemarle and Pamlico Sounds.
A storm surge watch is in effect for Edisto Beach, SC, to South Santee River, SC, and for north of Duck, NC, to the North Carolina/Virginia border.
A hurricane warning was issued for South Santee River, SC, north to Duck, NC, and a hurricane watch is in effect for Edisto Beach, SC, to South Santee River, SC.
A tropical storm warning is in effect for north of Duck, NC, to the North Carolina/Virginia border.
A tropical storm watch is in effect for north of the North Carolina/Virginia border to Cape Charles Light, VA, and for Chesapeake Bay south of New Point Comfort.
Hurricane-force winds now extend up to 60 miles from the eye of the storm, and tropical-storm-force winds now extend up to 175 miles from the center of the storm.
Washington, DC, Mayor Muriel Bowser and governors of North Carolina, South Carolina, Virginia and Maryland have declared states of emergency. More than 1 million people have been ordered to evacuate as the storm advances.
Evacuation orders for low-lying areas were issued Monday and continued Tuesday. Many major roads and arteries have reversed traffic flow to help those evacuate quickly.
Expected to make landfall by Friday, the impact of the storm will be widespread, with destructive winds, life-threatening storm surge, dangerous surf, torrential rainfall, flooding and the potential for tornadoes.
Florence will bring large rainfall totals through Saturday in North Carolina, north South Carolina and Virginia, from 15 to 25 inches, with isolated spots that may receive 35 inches, causing life-threatening flash flooding.
The impact of storm surge on the coast will depend on whether the storm's arrival coincides with high tide.
Areas along the coast from Cape Fear to Cape Lookout, NC, including The Neuse and Pamlico River, may experience storm surge from 9 to 13 feet.
Other areas facing a surge include:
- North Myrtle Beach to Cape Fear, 6 to 9 feet
- Cape Lookout to Ocracoke Inlet, NC, 6 to 9 feet
- South Santee River to North Myrtle Beach, SC, 4 to 6 feet
- Ocracoke Inlet to North Carolina/Virginia Border, 4 to 6 feet
- Edisto Beach, SC, to South Santee River, 2 to 4 feet
The East Coast isn't the only area facing the brunt of a storm. Tropical Storm Olivia is expected to move over Hawaii Wednesday or Thursday, KHNL reported.
And if that isn't enough, two disturbances in the Atlantic basin - one in the Gulf of Mexico and one out in the Atlantic - could develop into tropical systems.