The forecast track is, as of 9:00 AM UTC (I think 2 AM Pacific), slightly worse for New Orleans, but the intensity is a little better. However, NHC forecasts Gustav to restrengthen, then weaken a little as it approaches coast. I'm pretty sure that the windfield of Gustav is substantially smaller than was the case of Katrina. When near coast, the forecast advisory (see link) give hurricane force winds across 60 nautical miles in the northeast quadrant and tropical storm force winds to 175 nautical miles. This is a larger than average hurricane but may be just a little over half the size of Katrina at landfall (have not checked this). The maximum wave size is less for a smaller storm (so maybe less submarine pipeline failures and rigs washing up on shore), and Katrina was kind of shocking for the height of the storm surge in Mississippi: I assume that everything else being equal, the storm surge will be less (the path is not the same; Mississipi should be in much better shape).

There is quite a bit of "land" south of New Orleans. This is where the erosion and sinking of the delta becomes an issue. A hurricane should weaken over land, but not as quickly where marsh becomes water.

More for NHC page: probability table: 38% chance that at 1 PM Central time Gustav will be Cat 3, 22% Cat 4 (16% Cat 2)

From Wind Speed probability table: 35% cumulative probability that New Orleans will have hurricane force (presume sustained) winds. 91% chance that they will have at least tropical storm force winds.

Caution: I am mostly passing along selected information from the National Hurricane Center web site (linked): I am an amateur as far as hurricanes are concerned.

Chris

• National Hurricane Center