A tropical disturbance was first noted in a satellite picture taken on August 30. Soon after, a weak low pressure center associated with the system formed southwest of Acapulco, Mexico. The system later went through rapid intensification, becoming a tropical depression on August 31 and Tropical Storm Norma later that day. Initially with a loose organization, Norma continued to organize and strengthen, reaching its peak of on September 2. Satellite pictures showed cirrus outflow was greater in the tops of the feeder bands than in the eyewall chimney. On September 3, Navy reconnaissance reported a 992 mbar pressure, Norma's lowest.