Hurricane Katrina strengthened to a Category 5 storm yesterday with 257kph sustained winds as residents of south Louisiana jammed highways in a rush to flee the powerful storm.
The US National Hurricane Center put out a special advisory on the hurricane's gain in strength just before 8am. The boost came just hours after Katrina reached Category 4, with winds of 233kph, as it gathered energy from the warm water of the Gulf of Mexico.
A Category 5 hurricane -- the highest on the Saffir-Simpson scale -- can cause catastrophic damage. Only three Category 5 storms have hit the US since record-keeping began. The last was Hurricane Andrew, which hit South Florida in 1992, killing 43 and causing US$30.5 billion in damage.
The other two were the 1935 Labor Day hurricane that hit the Florida Keys and killed 600 people and Hurricane Camille, which devastated the Mississippi coast in 1969, killing 256 and leaving US$1.4 billion in damage.
Officials have been worried that not enough people were taking Katrina seriously enough.
"People need to take this very seriously and get to a safe area while they can," State Police Sergeant Frank Coates said -- before the new advisory was issued.
Katrina, blamed for nine deaths in South Florida, was expected to hit the Gulf Coast early today, and a hurricane warning was in effect from Morgan City to the Alabama-Florida line.
At 8am, Katrina's center was about 400km south-southeast of the mouth of the Mississippi River, the hurricane center said. It was moving west-northwest at about 19kph. Hurricane-force winds of at least 119kph extended up to 136km from the center.
The storm had the potential for storm-surge flooding of up to nearly 8m, topped with even higher waves, as much as 380mm of rain and tornadoes.
"I've been here 33 years, and we've always been concerned about New Orleans," National Hurricane Center director Max Mayfield said before Katrina reached Category 5. "I had to let the mayor know that this storm has the potential not only to cause large property damage, but large loss of life if people don't make the right decision."
Katrina could be a disaster for New Orleans because the bowl-like city sits below sea-level and needs levees and pumps to keep water out, Mayfield said.
New Orleans Mayor Ray Nagin was exploring the idea of ordering a mandatory evacuation.
US President George W. Bush had declared a state of emergency in Louisiana.
Hurricanes as powerful as Katrina usually make unpredictable fluctuations in strength, but all the conditions are there for the storm to still be a Category 5 when it hits the coast, said Chris Sisko, a meteorologist at the hurricane center. Even if Katrina weakens slightly, it does not bode well for New Orleans.
"With them sitting well below sea level, this is a potential set up for a catastrophic event that has never been seen before," Sisko said.
Katrina formed in the Bahamas and ripped across South Florida on Thursday as a Category 1 storm before moving into the Gulf of Mexico where surface water temperatures were as high as 30oC -- high-octane fuel for hurricanes.
Making matters worse, at least 100,000 people in the city lack the transportation to leave town. Nagin said the Superdome might be used as a shelter of last resort for people who have no cars, with city bus pickup points around New Orleans.
RSS