(Recasts with details on storm intensifying)
MEXICO CITY, Nov 25 (Reuters) - Hurricane Sandra on Wednesday strengthened to a Category 3 storm, becoming the strongest ever recorded in the eastern Pacific for this late in the year, as it heads toward the Mexican coast, the U.S. National Hurricane Center said.
Sandra was about 555 miles (893 km) southwest of the Pacific port of Manzanillo on Wednesday afternoon, the NHC said.
The hurricane is expected to weaken to a tropical storm as it reaches the Baja California peninsula early on Saturday morning, and then weaken further to a tropical depression as it moves over the Mexican mainland, according to the NHC's forecast.
"Interests in southern portions of the Baja California peninsula should monitor the progress of Sandra," the NHC said. "Tropical storm or hurricane watches may be required for portions of this area tonight or on Thursday."
Last month, Hurricane Patricia, which at one point registered as one of the strongest hurricanes ever recorded, landed on Mexico's Pacific coast, but did not inflict major damage.
Mexican state-owned oil company Pemex does not have any major installations in the storm's path. (Reporting by Elinor Comlay; Editing by Paul Simao and Chris Reese)