Fausto strengthened Friday into a Category 2 hurricane with 105 mph winds, about 1,385 miles east of Hilo, and is forecast to approach Hawaii next week.
The National Hurricane Center said the risk of wind and rainfall impacts in the Hawaiian Islands is increasing, though it is still too early to pinpoint where or how severe they could be.
Swells from Fausto could bring life-threatening surf and rip currents to parts of Southern California, even as the storm is expected to weaken gradually in coming days.
Genevieve formed farther east with 50 mph winds about 570 miles south of Zihuatanejo, Mexico, and forecasters expect it to intensify rapidly.