10:00 am August 27, 2005: NHC Advisory: Hurricane Watch for Southeastern Louisiana

The National Hurricane Center (NHC) issues its first hurricane watch for the southeastern coast of Louisiana, from east of Morgan City to the mouth of the Pearl River, including New Orleans. A hurricane watch likely will be required for other portions of northern gulf coast later today. Models also indicate Katrina will strengthen and could become a Category 5 hurricane, and the hurricane will likely move west-northwest during the next 24 hours. Katrina’s eye has begun a concentric eyewall cycle. Models now agree that Katrina is likely to make landfall in the next 72 hours over the northern Gulf Coast, however, the models disagree about where Katrina will make landfall: Two models indicate landfall will be near Morgan City or Intracoastal City, Louisiana. The other guidance ranges from Grand Isle, Louisiana to Pensacola, Florida. The official NHC forecast calls for landfall in Southeastern Louisiana—in 48-60 hours. (In fact, Katrina will make landfall in only 38 hours .) Other aspects of the NHC Advisory include:
Location: 405 miles southeast of the mouth of the Mississippi River.
Direction and Speed: West at 7 mph.
Maximum Sustained Winds: 115 mph, with higher gusts.
Estimated Central Pressure: 940 mb.
Size: Hurricane force winds extend outward from center up to 65 miles; tropical storm force winds extend outward up to 150 miles.
Probability that in the next 69 hours, Katrina’s eye will pass within 75 miles of:
Panama City, FL: 12 percent
Gulfport, MS: 18 percent
New Orleans, LA: 19 percent [National Hurricane Center, 8/27/2005; National Hurricane Center, 8/27/2005; National Hurricane Center, 8/27/2005]