4:00 pm August 28, 2005: NHC Advisory: Hurricane Potentially Catastrophic; Levee Overtopping Possible

The National Hurricane Center (NHC) Advisory leads by warning, “Potentially catastrophic Hurricane Katrina headed for the Northern Gulf Coast.” Conditions are already deteriorating along portions of the central and northeastern Gulf Coast, and they will continue to deteriorate throughout the evening. Katrina, still a Category 5 hurricane, is likely to make landfall with Category 4 or 5 intensity. The NHC reiterates that storm surge flooding will be 18-22 feet above normal, with increased surge to 28 feet in some areas, and warns that “some levees in the greater New Orleans area could be overtopped.” Katrina’s minimum central pressure is now the fourth lowest on record in the Atlantic. Other aspects of the NHC Advisory include:
Location: 150 miles south-southeast of the mouth of the Mississippi River
Direction and Speed: Northwest at near 13 mph
Maximum Sustained Winds: 175 mph with higher gusts
Estimated Central Pressure: 902 mb
Size: Hurricane winds extend 105 miles from the center; tropical storm force winds extend outward for 230 miles
Probability that in the next 69 hours, Katrina’s eye will pass within 75 miles of:
Panama City, FL: 5 percent
Gulfport, MS: 38 percent
New Orleans, LA: 47 percent [National Hurricane Center, 8/28/2005; National Hurricane Center, 8/28/2005; National Hurricane Center, 8/28/2005]