Tropical Storm Celia formed on Saturday in the Pacific off southern Mexico and could soon become a hurricane as it moves away from the coast, the US National Hurricane Center said.
Celia, the third named storm of the Pacific hurricane season, was 340 miles (550 km) south of the tourist resort of Acapulco, the Miami-based hurricane center said.
"Celia could become a hurricane later tonight or Sunday," the center said, warning the storm will cause dangerous surf conditions along the Mexican coast.
With winds up to 65 mph (100 kph), Celia was moving toward the west at 8 mph (13 kph) and was expected to remain well offshore from Mexico, the center said.
Tropical storm Blas, which on Thursday became the second named storm of the Pacific hurricane season, was 420 miles (670 km) south of Baja California and was expected to continue to move west, away from the coast.