GULF COAST — Isaac reached hurricane status Tuesday as it closed it on the Gulf Coast, threatening to deluge parts of the region with huge amounts of rain.
Maximum sustained winds were at 75 miles per hour, just strong enough to give the storm hurricane status, as of 11:20 a.m. CT, the National Hurricane Center said.
It could make landfall by evening, the center said.
"Hurricane conditions are expected to reach the coast by late afternoon," and the storm's center "should reach the coastline of southeastern Louisiana as early as this evening," forecasters said.
In New Orleans, the Army Corps of Engineers told CNN it was closing the gate to the West Closure Complex, one of the world's largest pump stations, capable of pumping storm water at 20,000 cubic feet per second.
As of 11:20 a.m. CT, Isaac's center was about 160 miles southeast of New Orleans, and about 75 miles south-southeast of the mouth of the Mississippi River, the hurricane center said.
Tropical-storm-force winds extended out as far as 185 miles, and already were battering coastal areas of Louisiana, Mississippi and Alabama, the hurricane center said.
Isaac is moving northwest at 10 mph, and it is expected to slow further, forecasters said, giving it time to wreak havoc in some areas.
Total rainfall could be 14 inches in many places, and isolated parts of southeast Louisiana, southern Mississippi, southern Alabama and the Florida panhandle could get as much as 20 inches, the hurricane center said.
"The combination of a storm surge and the tide will cause normally dry areas near the coast to be flooded," the hurricane center said.
And the storm could spawn tornadoes along the northern Gulf Coast on Tuesday, forecasters said.
President Barack Obama called on Gulf Coast residents to prepare. "Now's not the time to tempt fate," he said. "Now's not the time to dismiss official warnings. You need to take this seriously."
Gusts from the storm were already spreading inland, the hurricane center said.
In Biloxi, Mississippi, popular casinos began to close down Tuesday.
The hurricane center called on people at ports, docks and marinas to "urgently complete" emergency preparations. For people who live on boats, it was time to "make final preparations for securing your craft before leaving it."
"We have a plan in place to secure the city, and we have a plan to respond quickly in the event of emergencies," New Orleans Mayor Mitch Landrieu said. "We're confident that the work we've done in the last few years makes us fully capable of handling this type of storm."
By Tuesday morning, it was too late to evacuate New Orleans, Landrieu said.
Several New Orleans residents told CNN they planned to wait out the storm and were not concerned that the nightmare of Hurricane Katrina in 2005 would be repeated. Isaac is not predicted to bring such dire conditions, and law and order have improved vastly, they said.
If Isaac's landfall comes after midnight, it will hit on Katrina's seventh anniversary.
Jackie Grosch had to rebuild her home in Louisiana after Hurricane Katrina, but the St. Bernard Parish resident said she was going to wait Isaac out.
"Well, it gets old after a while -- packing up, taking the journey to wherever we're going to go. We thought about it and decided to stay," she said.
Nonetheless, her family is prepared with a generator, weather radio and life jackets -- "just in case."
A levee system fortified after Katrina will keep her home safe, she said.
"I don't know if it's going to be a true test, because they're saying it's not going to be that bad. But you never know what bad is. We didn't think Katrina was going to be bad, either."
Katrina made landfall as a Category 3 hurricane with 125-mph winds
Most of Katrina's nearly 1,800 deaths occurred when the protective levees around New Orleans failed, flooding the city. But Landrieu said the levees have had $10 billion in improvements since 2005, and the city's pump stations have backup generators ready in case of electrical outages.
"This is the best system that the greater New Orleans area has ever seen," said Col. Ed Fleming of the Army Corps of Engineers.
The U.S. Nuclear Regulatory Commission dispatched additional personnel to two nuclear plants in Louisiana: the Waterford plant about 20 miles west of New Orleans and the River Bend plant about 25 miles northwest of Baton Rouge.
As of 10 a.m. CT, a hurricane warning was in effect east of Morgan City, Louisiana, to the Alabama-Florida border, including metropolitan New Orleans. A hurricane watch was in effect from Intracoastal City to Morgan City, Louisiana.
Tropical storm warnings and watches extended to the east and west.
As the storm heads north, its rain is expected to benefit some drought-ravaged states like Arkansas, Illinois, Indiana and Missouri.
Some people in low-lying Louisiana parishes and coastal counties and barrier islands of Mississippi, Alabama and northwest Florida were told to clear out ahead of the storm. In Alabama, state Emergency Management Agency Director Art Faulkner warned that strong winds and high water may affect the Mobile area even if the storm hits as far west as Louisiana.
"It is a very large storm," Faulkner said. "And oftentimes we confuse and focus on a specific dot that may be identified as the center of the storm when very dangerous conditions may exist as far as 200 miles from that specific dot."
The storm lashed Cuba and the Florida Keys over the weekend after slamming into Haiti, where at least 19 people had been reported dead by Monday, the country's civil protection agency reported.
The Hurricane Center projected storm surges of up to 12 feet in Mississippi and southeastern Louisiana.
But on Dauphin Island, south of Mobile, many residents were preparing to sit out Isaac at home as well.
"We are boarding up (and) getting supplies ready," said Alexa Alexander, who lives and tends bar on the island. "We've had a little bit of people leave Dauphin Island, but not much. Most of the locals are going to ride it out."
Dauphin Island was badly damaged by Katrina, which cut the island in half -- a gouge since filled by sand and rock.
In nearby Bayou La Batre, Alabama, shrimpers hunkered down.
"All the boats are coming in. We're anchoring them down and getting ready for this blow, hoping it's not too bad," Dominick Ficarino, the owner of Dominick's Seafood, told affiliate WPMI-TV.
Airports across the region also made plans to shut down as the storm passed. New Orleans shut its international airport after its last flight Monday night, spokesman Ryan Berni said, while smaller airports in Mississippi, Alabama and Florida also announced closures starting Tuesday.
Mississippi officials dispatched 1,500 National Guard troops to the state's three southern counties to help with emergency operations, as well as extra state troopers to ease traffic flow.
The state has distributed 10,000 sandbags to residents ahead of the storm.
"In short, we have done everything in our power to be prepared for the storm," Mississippi Gov. Phil Bryant said.
Most of the storm's ferocity bypassed Florida's west coast and the Republican National Convention in Tampa, where the schedule will begin in earnest Wednesday after organizers pushed events back a day because of concerns about the storm. The system passed well west of Tampa, although it did soak the bay area with heavy rain and blustery winds.