The U.S. National Hurricane Center warned Tuesday that Tropical Storm Cosme is strengthening in Pacific waters southwest of Mexico after it was upgraded to a hurricane.

Reports out of the center in Miami say the storm gained maximum sustained winds of up to 65 mph (105 kph), with increasing winds expected in the next 48 hours. Cosme is centered about 320 miles (515 kilometers) southwest of Manzanillo, Mexico, and is moving northwest at 14 mph (22 kph).

While no coastal watches or warnings were in effect, the storm was expected to begin affecting portions of Mexico's Pacific coast in the next 24 hours, generating dangerous conditions from Manzanillo to Cabo Corrientes overnight, with life-threatening surf and rip currents possible.