Context of '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]

The National Hurricane Center (NHC) expands the hurricane watch westward to Intracoastal City, Louisiana and eastward to the Florida-Alabama border, and states that a hurricane warning likely will be required for portions of the Northern Gulf Coast later tonight or Sunday. Landfall in southeast Louisiana is likely in “a little under” 48 hours. (In fact, Katrina will make landfall in 32 hours .) According to the NHC, Katrina will likely strengthen, and may become a Category 5 hurricane before landfall. Katrina likely will move west-northwest during the next 24 hours. Models continue to diverge, with some indicating Katrina will turn northward, while others indicate Katrina will shift westward. Other aspects of the NHC Advisory include:
Location: 380 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: 945 mb
Size: Hurricane force winds extend outward from center up to 45 miles; tropical storm force winds extend outward up to 160 miles
Probability that in the next 69 hours, Katrina’s eye will pass within 75 miles of:
Panama City, FL: 12 percent
Gulfport, MS: 20 percent
New Orleans, LA: 21 percent [National Hurricane Center, 8/27/2005; National Hurricane Center, 8/27/2005; National Hurricane Center, 8/27/2005]

The National Hurricane Center (NHC) elevates the hurricane watch to a hurricane warning for the area between area between Morgan City, Louisiana and the Alabama-Florida border. A hurricane warning means that hurricane conditions are expected in the, within the next 24 hours. “Preparations to protect life and property should be rushed to completion.” The NHC warns that Katrina can cause a costal storm surge of 15-20 feet above normal, with higher surges to 25 feet near and to the east of where landfall occurs. Katrina’s wind field is expanding and conditions are ripe for the hurricane to strengthen even further. “The bottom line is that Katrina is expected to be an intense and dangerous hurricane heading toward the North Central Gulf Coast… and this has to be taken very seriously.” The NHC also issues a tropical storm warning and hurricane watch for parts west and east of the warning areas. Other aspects of the NHC Advisory include:
Location: 335 miles south-southeast of the mouth of the Mississippi River
Direction and Speed: West-northwest at 7 mph
Maximum Sustained Winds: 115 mph, with higher gusts
Estimated Central Pressure: 939 mb
Size: Hurricane force winds extend outward from center up to 45 miles; tropical storm force winds extend outward up to 160 miles
Probability that in the next 69 hours, Katrina’s eye will pass within 75 miles of:
Panama City, FL: 12 percent
Gulfport, MS: 23 percent
New Orleans, LA: 26 percent [National Hurricane Center, 8/27/2005; National Hurricane Center, 8/27/2005; National Hurricane Center, 8/27/2005]

The National Hurricane Center (NHC)‘s midnight advisory leads with: “Potentially catastrophic [Category 5] Hurricane Katrina continues to approach the Northern Gulf Coast…sustained hurricane-force winds nearing the Southeastern Louisiana coast.” Already, a wind gust to 98 mph has been reported from Southwest Pass Louisiana. 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, and may overtop New Orleans’ levees. Some changes to Katrina’s structure indicates that there could be some weakening, although the NHC reiterates that Katrina likely will still be a very dangerous Category 4 hurricane at landfall. Other aspects of the NHC Advisory include:
Location: 90 miles south-southwest of the mouth of the Mississippi River; 150 miles south-southeast of New Orleans
Direction and Speed: North-northwest at near 10 mph
Maximum Sustained Winds: Near 160 mph with higher gusts
Estimated Central Pressure: 908 mb
Size: hurricane winds now extend 105 miles from the center; tropical storm force winds extend 230 miles [National Hurricane Center, 8/29/2005]

The National Hurricane Center (NHC) advises that Katrina is now a Category 2 hurricane with sustained winds of nearly 105 mph. Katrina remains huge, with hurricane force winds extending 125 miles from the center, and tropical storm force winds extending 230 miles. Katrina’s center is now 40 miles south-southwest of Hattiesburg, Mississippi. Minimum central pressure has increased to 940 MB. [National Hurricane Center, 8/29/2005]

The National Hurricane Center (NHC) advises that Katrina is now a still-dangerous Category 1 hurricane, with sustained winds of nearly 95 mph. The hurricane remains huge, with hurricane force winds extending 125 miles from the center, and tropical storm force winds extending 230 miles. Katrina’s center is now 20 miles south-southwest of Hattiesburg, Mississippi. [National Hurricane Center, 8/29/2005]