I was just looking at http://www.wunderground.com
Found this entry on Dr. Jeff Master's blog:
New Orleans finally got serious and ordered an evacuation, but far too late. There is no way everyone will be able to get out of the city in time, and they may be forced to take shelter in the Superdome, which is above sea level. If Katrina makes a direct hit on New Orleans as a Category 4 hurricane, the levees protecting the city will be breached, and New Orleans, which is 6 - 10 feet below sea level, will fill with water. On top of this 6 feet of water will come a 15 foot storm surge, and on top of that will be 20 foot waves, so the potential for high loss of life is great. Given the current track and intensity forecast, I'd put the odds of this at about 20%
Day After Tomorrow?