MYRTLE BEACH, South Carolina (CNN) -- Tropical Storm Hanna's winds and sea surge battered the Carolina coast early Saturday, while flash floods and tornadoes threatened inland.
As of 2 a.m. ET Saturday, Hanna was about 30 miles (48 kilometers) south of Myrtle Beach, South Carolina and about 60 miles (97 kilometers) southwest of Wilmington, North Carolina, according to the National Hurricane Center in Miami, Florida.
The storm is carrying maximum sustained winds near 70 mph with higher gusts, just below hurricane status of 74 mph, the hurricane center said.
Forecasters warn that "it would only take a small increase in wind speed for Hanna to become a hurricane."
The storm was expected to hit near North Myrtle Beach, South Carolina between 2 a.m. and 4 a.m. ET, according to CNN projections.
The hurricane center said "large and dangerous battering waves" could be expected near and east of the path of Hanna's center as the coastal storm surge reaches 3 to 5 feet above normal tide levels.
Those waves could be seen early Saturday along the beaches of Oak Island, North Carolina, where sand dunes were flattened by repeated pounding.
The island's Ocean Crest pier, rebuilt after Hurricane Floyd destroyed it nine years ago, appeared to be holding up well as large waves battered its pilings.
Rainfall accumulations from Hanna could total three to seven inches from coastal South Carolina northward through central and eastern North Carolina into the mid-Atlantic states, the NHC said. Some isolated areas could get as much as 10 inches of rain.
"The potential for flash flooding will be significant for the mid-Atlantic region and southern New England," the NHC said.
Forecasters also warned that isolated tornadoes were possible over the coastal plains of the Carolinas and southeast Virginia on Saturday morning.
The storm, which had spent several days meandering around the southern Bahamas, was moving north at a fast clip of about 20 mph, and forecasters expected it to speed up even more Saturday before turning northeast.
A tropical storm warning extends from Altamaha Sound, Georgia, to Sandy Hook, New Jersey, including all of Chesapeake Bay, the tidal Potomac River, Washington and Delaware Bay.
North Carolina and South Carolina opened emergency centers in anticipation of Hanna's arrival, and North Carolina Gov. Mike Easley declared a state of emergency, as have the Maryland and Virginia governors.
No mandatory evacuation orders were issued in either North Carolina or South Carolina, but South Carolina Gov. Mark Sanford urged the voluntary evacuation of two northeast counties.
A hurricane watch was in effect from north of Edisto Beach, South Carolina -- about 30 miles south of Charleston -- to Currituck Beach Light, North Carolina.
A tropical storm watch is in effect from north of Sandy Hook, New Jersey, to Watch Hill, Rhode Island, including Long Island, the hurricane center said.
Meanwhile, Ike -- "a small, but impressive hurricane" -- is still far out in the Atlantic, forecasters said, but they warned that it could come ashore in southern Florida as a Category 4 storm by Tuesday night. View a map of Ike's projected path
Ike's top winds of 115 mph keep it a Category 3 storm on the Saffir-Simpson scale, according to the hurricane center's 11 p.m. advisory.
The forecast calls for Ike to be a Category 4 hurricane as it approaches the Florida coast and possibly moves into the Gulf of Mexico next week.
Ike was centered 430 miles (690 kilometers) north-northwest of the Leeward Islands and was moving west-southwest about 15 mph (24 kph).
Ike is expected to continue westward for the next several days before turning west-northwest, the hurricane center said.
"The big question is, when will the turn take place," the forecasters said.
Some computer models predict that Ike will go south over Cuba or the Straits of Florida, while others say it will move more to the north near the Bahamas and over the southern tip of Florida, forecasters said.