'This is going to be an unprecedented event.'ДЎ1 a.m.: Hurricane Katrina has mushroomed into one of the most powerful hurricanes ever to form in the Atlantic. 'We're facing the storm most of us have feared,' Nagin said.

Tens of thousands of New Orleans residents begin streaming out of the city. The eye of the storm is about 310 miles (500 kilometers) south of the mouth of the Mississippi River.Д©:30 a.m.: New Orleans Mayor Ray Nagin issues a mandatory evacuation order. 'When we were flying into it Saturday, its circulation covered the entire Gulf of Mexico.' SUNDAY, AUGUST 28Дў a.m.: Hurricane Katrina's winds have increased to 145 miles an hour (235 kilometers an hour), making it a Category Four storm. Landsea, a meteorologist with the National Oceanic and Atmospheric Administration, was aboard a flight into Hurricane Katrina. 'It was certainly very strong and also was very large,' Chris Landsea said later. SATURDAY, AUGUST 27ДҐ a.m.: Katrina's strongest winds have reached 115 miles an hour (185 kilometers an hour), making it a Category Three hurricane.Дuring the day: Hurricane-hunter aircraft fly into Hurricane Katrina to measure wind speed, barometric pressure, ocean surface temperature, and other data. The eye of the storm is now about 460 miles (740 kilometers) southeast of the mouth of the Mississippi River in Louisiana. In only a few hours, the storm's strongest winds have increased to about a hundred miles an hour (160 kilometers an hour).Дuring the day: Governors Kathleen Blanco of Louisiana and Haley Barbour of Mississippi declare states of emergency in their respective states.ДЎ1 p.m.: The National Hurricane Center predicts that Katrina will become a major hurricane by the time it reaches the central Gulf of Mexico. 'A lot of the live-aboards in Boot Key Harbor were surprised to find their boats in new spots.'ДЎ1:30 a.m.: The National Hurricane Center reports that the hurricane is 'rapidly strengthening' as it crosses the Gulf of Mexico's very warm waters. 'We went to bed last night expecting some possible rain and woke up this morning to learn that Katrina was 75 miles north of Marathon ,' says Dan Gallagher, resident of Grassy Key.

Keys residents are surprised by Katrina's strength as it passes offshore. Its strongest winds are about 75 miles an hour (120 kilometers an hour), and its eye is about 70 miles (115 kilometers) northwest of Key Largo. Its strongest winds are about 70 miles an hour (115 kilometers an hour).ДЈ a.m.: The storm's center has emerged from the Florida peninsula and starts strengthening almost immediately as it touches the warm waters of the Gulf of Mexico.ДҐ a.m.: Katrina reintensifies into a hurricane. Its center is about 45 miles (70 kilometers) northwest of Key Largo, Florida. FRIDAY, AUGUST 26ДЎ a.m.: Katrina weakens and is reclassified as a tropical storm.

The storm's top winds are 80 miles an hour (130 kilometers an hour). The storm is about 15 miles (25 kilometers) east of Fort Lauderdale, Florida, and about to make landfall.Д§ p.m.: The eye of Hurricane Katrina comes ashore between North Miami Beach and Hallandale Beach on Florida's southeastern coast. Its strongest winds are about 75 miles an hour (120 kilometers an hour), making it a Category One hurricane. THURSDAY, AUGUST 25ДҐ p.m.: Katrina has continued to strengthen and is now a hurricane. Its strongest winds are blowing at about 40 miles an hour (65 kilometers an hour). It is now tropical storm Katrina, the 11th named storm of 2005, about 230 miles (370 kilometers) east of Miami. WEDNESDAY, AUGUST 24ДЎ1 a.m.: The storm has strengthened, become more organized, and been given a name. The weather system is about 350 miles (560 kilometers) east of Miami. The advisory notes that the season's 12th tropical depression has formed over the Bahamas. 5 p.m.: The National Hurricane Center in Miami, Florida, issues its first advisory about the tropical system that will become Hurricane Katrina.

Katrina hurricane track