10:00 pm August 28, 2005: NHC Advisory: Potentially Catastrophic Katrina Bears Down on Northern Gulf Coast

The National Hurricane Center (NHC) again leads its advisory by warning that “Potentially catastrophic Hurricane Katrina” continues to approach the northern gulf coast. Still a Category 5 hurricane, Katrina will likely turn north in the next 12-24 hours. Katrina remains quite large, and will likely cause storm surge flooding of 18-22 feet above normal, with increased surge to 28 feet in some areas. The surge may overtop New Orleans’ levees. Some changes to Katrina’s structure indicates that there could be some weakening, although Katrina likely will still be a very dangerous Category 4 hurricane at landfall. While “there is great significance for the City of New Orleans in the details of the path of Katrina, the path could vary 30-50 miles 12-18 hours from landfall.” Other aspects of the NHC Advisory include:
Location: 105 miles south of the mouth of the Mississippi River; about 170 miles south-southeast of New Orleans
Direction and Speed: North-northwest at near 10 mph
Maximum Sustained Winds: 160 mph with higher gusts
Estimated Central Pressure: 904 mb
Size: hurricane winds extend 105 miles from the center; tropical storm force winds extend 230 miles
Probability that in the next 69 hours, Katrina’s eye will pass within 75 miles of:
Panama City, FL: 2 percent
Gulfport, MS: 54 percent
New Orleans, LA: 59 percent [National Hurricane Center, 8/28/2005; National Hurricane Center, 8/28/2005; National Hurricane Center, 8/28/2005]