A direct hit from Hurricane Rita was still unlikely, but the Category 4 storm veered on a more northerly course toward a Saturday landfall in Texas that put New Orleans on the eastern edge of tropical storm warning.
Rita’s rains and a predicted one-metre storm surge could bring New Orleans dangerously close to predictions that the fractured levees can only handle up to 15cm of rain and a storm surge of three to 3.5 metres.
“Right now, it’s a wait and see and hope for the best,” said Army Corps of Engineers spokesperson Mitch Frazier. He added that the new forecast brought renewed urgency to efforts to shore up levees with sandbags and bring in more portable pumps.
Yesterday’s showers were the first measurable rainfall in New Orleans since Hurricane Katrina’s August 29 landfall broke the levees in several places and flooded 80% of the city. Only spotty showers were falling at midmorning, but forecasters said there could be brief periods of heavy downpours as Rita’s squall bands moved through.
Mr Frazier said his biggest concern was the storm surge, which the National Hurricane Centre said will be about a metre above normal in the parts of Louisiana and Mississippi affected by Katrina. But a slight turn could increase that dramatically. A tidal surge of 4.5 to six metres was expected from Corpus Christi, Texas, to south-central Louisiana.
Engineers say a three to 3.5m surge was required to overtake the levees at 17th Street and the London canal in New Orleans. But in neighbouring St. Bernard Parish, a surge of 1.5-1.8m was all that was needed to swamp the area again.
If the levees fail again, the areas of New Orleans that are most likely to flood are the same neighbourhoods inundated by Katrina.
“If it’s a quick, fast rain, we’ll see localised flooding,” Mr Frazier said.
The process of getting the water from Katrina out was nearly complete, with only about 10% of the city still flooded and the Corps is confident it will be able to quickly pump water out again.
Searchers looking for bodies continued smashing into homes that had been locked or submerged under Katrina’s highest flood-waters. The death toll in Louisiana alone increased to 832 yesterday, pushing the body count to at least 1,069 across the Gulf Coast region.
New Orleans Mayor Ray Nagin continued to urge residents to get out of the city. A mandatory evacuation order is in effect for the entire east bank of the Mississippi, and some 500 buses were standing by at the Convention Centre, but few seemed to be taking advantage. Only 27 people had been evacuated by the end of Wednesday.
Thursday’s shifting forecast for Rita prompted Governor Kathleen Blanco to urge evacuations for everyone in the coastal parishes of southwest Louisiana, an area of 300,000 to 500,000 people.
“Rita took a turn to the east last night and south-west Louisiana is now in danger,” she said. “Hurricane force winds will rip much of western Louisiana.”