Yeah, you've got at least three problems other than the altitude, maybe four, in NO: (1) Lake Ponch; (2) the possibility of the Mississippi River being pushed backwards, with heavy flooding at the points where the stoppage occurs; (3) the rainfall of a sllloooww moving storm; and (4) maybe a storm surge, then they're actually reasonably inland, excepting the River.
What effect would that have, on people as far up as Baton Rouge?