MIAMI (AP) -- Forecasters say Isaac is gaining strength, susptaining winds of 80 MPH as it makes its way toward Louisiana.
The U.S. National Hurricane Center said Tuesday that Isaac hit hurricane strength as it moved over the warm, open waters of the Gulf of Mexico.
Isaac is expected to make landfall over southeastern Louisiana, possibly the New Orleans area, either late Tuesday or early Wednesday.
Keep up with Isaac in the WVEC.com Hurricane Center.
Shelters were open for those who chose to stay or missed the chance to get away before the outer bands of the large storm blow ashore ahead of a forecast landfall in southeast Louisiana on Tuesday night or early Wednesday. However, with the exception of some low-lying areas, officials had not ordered mass evacuations.
In Houma, a city southwest of New Orleans, people filled a municipal auditorium-turned-shelter. However, in the bayou country of Terrebonne Parish off Highway 24, storms pose a perennial dilemma for those living a hardscrabble life.
While some of the homes along Bayou Terrebonne and other nearby waterways show signs of affluence, this section of Louisiana 24 is mostly lined with trailer homes or small, often run-down houses. Staying could be dangerous, but many here who could be in harm's way have nowhere to go and little money to get there, especially given the high price of gasoline.
Monica Boudreaux lives in a trailer on low-lying land but was talking Tuesday morning with a cousin who lived closer to the bayou. They and two friends chatted as the storm approached. Boudreaux laughed when asked what she'll do if the storm hits.
"I'm surrounded by all family," she said, referring to her friends as well as her cousin. "I'll just pick up my little fat feet and run, I guess."
Forecasters warned that Isaac was a large storm whose effects could reach out 200 miles from its center. Water may be worse than wind because the storm could push walls of water while dumping rain to flood the low-lying coast in Louisiana, Mississippi, Alabama and the Florida Panhandle.
So far, the main damage in the United States was political: Republicans cut one day off their presidential nominating convention in Tampa in case the storm struck there, though in the end it bypassed the bayside city. Isaac is also testing elected officials along the Gulf from governors on down to show they're prepared for an emergency response.
Isaac's track is forecast to bring it to New Orleans seven years after Katrina hit as a much stronger storm on Aug. 29, 2005.
This time, federal officials say the updated levees around the city are equipped to handle storms stronger than Isaac. The Army Corps of Engineers was given about $14 billion to improve flood defenses, and most of the work has been completed. The levees surrounding New Orleans are designed to withstand far more than the forecast 12-foot surge. And the city's flood control system can pump out an inch of water per hour for the first hour, and a half-inch of water each hour after that.
But with landfall expected near the Katrina anniversary, anxiety was high, especially in the Lower 9th Ward, wiped out by Katrina after floodwalls burst and let the waters rush in.