Context of '11:00 pm EDT August 23, 2005: NHC Advisory: Tropical Depression 12 is Organizing'

The National Hurricane Center (NHC) issues its second forecast/advisory for Tropical Depression 12, indicating that the storm is organizing and moving northwest. It issues a tropical storm watch for portions of the Florida Keys and Florida East Coast. A tropical storm watch means that tropical storm conditions are possible within the watch area, generally within 36 hours. [National Hurricane Center, 8/23/2005]

The National Hurricane Center (NHC) issues its third advisory for Tropical Depression 12, indicating that the storm is organizing and moving northwest. The tropical storm watch for portions of the Florida Keys and Florida East Coast remains in effect. A hurricane watch may be required later today for portions of the Florida East Coast. [National Hurricane Center, 8/24/2005]

The National Hurricane Center (NHC) issues its fifth forecast/advisory. Tropical Depression 12 has been upgraded to Tropical Storm Katrina. The NHC expects additional strengthening in the next 24 hours. The NHC models indicate that Katrina will keep building slowly eastward, moving across South Florida over the next 36-48 hours and into the Gulf of Mexico within 72 hours. The models, however, are inconsistent in predicting the next landfall. One model indicates Katrina will hit New Orleans, others indicate Katrina will make second landfall on the Northern Florida Peninsula. Other aspects of the NHC Advisory include:
Location: At 25.6 N, 77.2 W
Direction and speed: NW at 9 mph
Maximum Sustained Winds: Near 45 mph with higher gusts
Probability that Katrina’s eye will pass within 75 miles of:
West Palm Beach, FL: 29 percent
Panama City, FL: 10 percent
Gulfport, MS: 3 percent
New Orleans, LA: 2 percent [National Hurricane Center, 8/24/2005; National Hurricane Center, 8/24/2005; National Hurricane Center, 8/24/2005]

The National Hurricane Center (NHC) issues a special advisory that, with sustained winds of 145 mph, Katrina has become a Category 4 hurricane. Katrina also continues to grow, as hurricane winds now extend 70 miles from the center, and NHC warns that Katrina can yet strengthen, and will likely move northwest later today. Other aspects of the NHC Advisory include:
Location: 310 miles south-southeast of the mouth of the Mississippi River
Direction and Speed: West-northwest at 8 mph
Maximum Sustained Winds: 145 mph, with higher gusts
Estimated Central Pressure: 935 mb
Size: Hurricane force winds extend outward from center up to 75 miles; tropical storm force winds extend outward up to 160 miles [National Hurricane Center, 8/28/2005]

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]