(Adds Max becomes tropical storm, details on conditions)
MEXICO CITY, Sept 14 (Reuters) - Hurricane Max was downgraded to a tropical storm on Thursday evening, bearing down on a region with the popular tourist resorts of Acapulco, Zihuatanejo and Ixtapa.
Max's maximum sustained winds decreased to 70 miles per hour (113 km per hour) on Thursday evening, and the storm was about 80 miles (129 km) east of Acapulco, the National Hurricane Center in Florida said.
The storm is expected to continue weakening dramatically as it moves inland over Southern Mexico, and it will likely be downgraded to a tropical depression on Thursday evening.
Nevertheless, the center warned of heavy rains and flooding in the coastal states of Guerrero and Oaxaca.
In the state of Guerrero, home to some of Mexico's major tourist resorts, Max could dump as much as 20 inches (51 cm) of rain in coastal areas, the NHC said, potentially triggering flash floods and mudslides.
The storm is bad news for Acapulco as tourists prepare to travel to the city to celebrate Mexico's Independence Day this weekend.
Meanwhile, tropical storm Norma formed in the Pacific on Thursday, according to the NHC. The storm, which is currently 360 miles (579 km) south of Cabo San Lucas, on the southern tip of the Baja California peninsula, could become a hurricane by late Friday.
Max arrives a week after a powerful 8.1-magnitude quake shook southern Mexico, destroying thousands of buildings in the state of Oaxaca and killing at least 98 people nationwide. (Reporting by Gabriel Stargardter, Julia Love and Miguel Gutierrez; Editing by Lisa Shumaker and Grant McCool)