Katrina attained Category 5 status on the morning of August 28 and reached its peak strength at 1800 UTC that day, with maximum sustained winds of 175 mph (280 km/h) and a minimum central pressure of 902 mbar (26.6 inHg).
On August 28, Alabama Governor Bob Riley declared a state of emergency for the approaching Hurricane Katrina. On the same day, he requested President Bush to declare "expedited major disaster declaration" for six counties of South Alabama, which was quickly approved. Three-hundred and fifty national guardsmen were called on duty by August 30.
The National Weather Service's New Orleans/Baton Rouge office issued a vividly worded bulletin on August 28 predicting that the area would be "uninhabitable for weeks" after "devastating damage" caused by Katrina, which at that time rivaled the intensity of Hurricane Camille.