MIAMI – Tropical Storm Priscilla was strengthening slowly in the Pacific Ocean off the coast of Mexico early Sunday.

The National Hurricane Center, based in Miami, reported that Priscilla is a “large tropical storm” with winds reaching tropical storm strength up to 140 miles (220 kilometers) from its center.

The storm’s top sustained winds are 65 mph (100 kph), and it is currently positioned roughly 305 miles (495 kilometers) south-southwest of Cabo Corientes, moving northwest at 5 mph (7 kph).

A tropical storm watch has been put in place for a section of the southwestern Mexican coastline, spanning from Punta San Telmo to Punta Mita, with the possibility of tropical storm conditions on Sunday and Monday. Rainfall could reach up to 6 inches (15 centimeters), and there is a risk of dangerous surf and rip currents along the coast.

Priscilla was forecast to reach hurricane status by Sunday night or early Monday and generally move parallel to the coast in the coming days.

In the Pacific, another tropical storm named Octave is drifting away from Mexico, with no landfall expected and no coastal warnings or watches currently in effect.

Its maximum sustained winds strengthened slightly to 70 mph (110 kph).