Harvey made landfall in Texas on Friday night as the strongest hurricane to hit the U.S. in more than a decade. By Saturday afternoon it had been downgraded into a tropical storm, but it had dumped 18 inches (half a meter) of rain on some areas and caused catastrophic flooding in the coming days. The storm made a second landfall early Wednesday, this time in western Louisiana.
Here is a timeline of key moments in the storm's development:
AUG. 17 Tropical Storm Harvey is named, six hours after the National Hurricane Center in Miami issues a potential tropical cyclone for several small Caribbean islands.
AUG. 19 Moving westward between the northern coast of South America and the larger Caribbean islands, Harvey is downgraded to a tropical depression, with maximum sustained winds of 35 mph (56 kph). Six hours later, it is further downgraded to a tropical wave.
AUG. 23 Harvey regenerates into a tropical depression about 535 miles (860 kilometers) southeast of Port O'Connor, Texas, with maximum sustained winds of 35 mph (56 kph).
AUG. 24 After quickly strengthening over the course of a day, Harvey becomes a hurricane, with maximum sustained winds of 85 mph (140 kph). It is about 325 miles (525 kilometers) southeast of Port O'Connor, and Texas coastal communities in its path are urged to complete their preparations. By midnight, it is upgraded to a Category 2 hurricane and is 220 miles from Port O'Connor, with sustained maximum winds of 100 mph (160 kph).
FRIDAY, AUG. 25, 2 P.M. Harvey is upgraded to a Category 3 hurricane, with sustained maximum winds of 120 mph (195 kph). It is centered about 75 miles (120 kilometers) southeast of Corpus Christi. By 6 p.m., Harvey is a Category 4 storm just 45 miles from the city, with maximum sustained winds of 130 mph (215 kph).
FRIDAY, AUG. 25, 10 P.M. Harvey makes landfall as a Category 4 hurricane when the eye of the storm comes ashore between Port Aransas and Port O'Connor, two communities on a spit off the coast of mainland Texas near Corpus Christi.
SATURDAY, AUG. 26, 2 A.M. Harvey is centered about 15 miles inland and is weakening as it slowly passes over land. It has been downgraded to a Category 3, with maximum sustained winds of 115 mph (185 kph). Two hours later, it is downgraded further to a Category 2.
SATURDAY, AUG. 26, 5 A.M. With maximum sustained winds of 90 mph (150 kph), Harvey is downgraded to a Category 1 storm. Forecasters warn of potentially catastrophic flooding in the coming days. Hours later, it is downgraded yet again to a tropical storm and it is blamed for its first death — that of a person in Rockport, which sustained heavy damage.
SUNDAY, AUG. 27 Harvey pours devastating floods into Houston, leaving thousands of people to seek higher ground. The U.S. Coast Guard reports saving more than 1,000 people. The Houston area records nearly 25 inches of rain by Sunday, with other areas recording 27 inches. Houston Gov. Greg Abbott activates 3,000 National Guard and State Guard members to the city. Harvey is blamed for a second death.
MONDAY, AUG. 28 A woman in the town of Porter, northeast of Houston, is killed when a large oak tree dislodged by heavy rains toppled onto her trailer home, marking the third death during the storm. Officials report more than 6,000 people being rescued by police and the Coast Guard since the storm hit. Harvey, which dropped 30-plus inches of rain in some places, increases slightly in strength as it drifts back over the warm Gulf of Mexico.
TUESDAY, AUG. 29 Harvey hovers over the gulf as a tropical storm about 100 miles from Texas shore, with forecasters expecting it to turn back toward southeast Texas. Several people are feared missing, including six from one family, while 9 deaths are confirmed. About 300,000 customers remain without power. President Donald Trump travels to Corpus Christi and Austin for on-the-ground briefings on disaster response efforts. Houston Mayor Sylvester Turner imposes a curfew on the city, while federal and local authorities report 13,000 people being rescued since the storm hit.
WEDNESDAY, AUG. 30 Harvey, still a tropical storm, makes a second landfall, this time in western Louisiana, where forecasters anticipated between 5 and 10 inches of rain.