MIAMI, Florida (CNN) -- Tropical Storm Hanna sped toward the southeastern coast of the U.S. on Friday, and forecasters predicted that the storm would strengthen slightly before reaching land Saturday.
As of 11 p.m. ET, Hanna was about 140 miles south of Wilmington, North Carolina, carrying maximum sustained winds near 70 mph with higher gusts, just below hurricane status of 74 mph, the Miami-based National Hurricane Center said. View a map of Hanna's projected path »
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.
The storm was expected to hit near the South Carolina-North Carolina state line between 2 a.m. and 4 a.m. ET, according to hurricane center projections.
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.
The center said the storm is likely to strengthen only slightly but warned that it is still possible for Hanna to become a hurricane before hitting land.
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 »
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. Watch Hanna's aftermath in Haiti »
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.
Charleston, South Carolina, has prepared for the worst. Workers began boarding up city buildings this week, and firefighters filled and distributed sandbags to residents and business owners. Backup generators were fueled and positioned at key locations across the city.
City offices were closed Friday in anticipation of the storm, as were Charleston County schools.
In Wrightsville Beach, in coastal North Carolina, stores and businesses remained open as the community wrapped up its summer season.
"We look at it more or less like a nor'easter, a bad storm with some wind and rain and hopefully not a lot of damage," Mayor Stephen Whalen said.
Some buildings were boarded up, and billboards were taken down in Morehead City, 92 miles north of Wrightsville Beach, said Jamie Fulk, the deputy chief for the fire department.
"We're prepared. We've done all we can do to get prepared; we're basically waiting to see what the storm is going to do," he said. The "public's very much aware of what's going on. ... [They're] waiting to see if it's going to intensify."
Tropical storm-force winds extended up to 290 miles from the center.
"People are reminded that there is very little difference between a strong tropical storm and a minimal hurricane," forecasters said. iReport.com: Are you prepared for the storm?
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. Watch Myrtle Beach hotel workers prepare for Hanna »
Meanwhile, Ike's top winds of 115 mph keep it a Category 3 storm on the Saffir-Simpson scale, according to the hurricane center's 8 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. Watch a view of Ike from space »
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.