Reply #14: But on Thursday, even as late as 11PM it was a minimal Category 1...

[Brotherjohn]

... (75mph), projected to make landfall as a minimal Category 2 (95-100mph), in the Panama City, FL area... some 300 miles to the east. New Orleans was on the extreme outer edge of the cone of probability.
http://www.nhc.noaa.gov/archive/2005/KATRINA.shtml

If full evacuations of cities, or even low-lying coastal areas, were ordered that early based on hurricane projections, the entire Gulf Coast would be in a near-constant state of evacuation or returning from evacuations (for half of the year).

You need to be more certain than that, or you run the risks mentioned above, plus you run a major risk of destroying the economy of the Gulf Coast. I do not speak lightly, or from an uninformed perspective. Panhandle FL and Alabama beaches' economies have been dealt very serious blows from repeated hurricanes and evacuations lately.

You absolutely cannot evacuate that early. It would be foolish. For Blanco to have done what you suggest, she would have had to have been psychic. That is the whole problem, and why it is so difficult, and why you are ALWAYS cutting it close.