Hurricane Polo is a strong Category 4 storm off Mexico. See its path.

Hurricane Polo regained Category 5 status as its intensity fluctuated off Mexico’s southwestern coast. It had maximum sustained winds of 180 mph on Friday, well above the 157 mph needed to reach Category 5 status. 

More fluctuations are possible, but the storm is expected to make landfall in California’s Big Sur as a powerful hurricane, the National Hurricane Center said. 

The storm was moving west-northwest on Saturday morning. 

Elsewhere in the Pacific, Nolo strengthened into a hurricane as it headed for Hawaii’s Big Island this weekend.

Maps show Hurricane Polo’s projected path

As of Saturday, Polo’s core was about 425 miles west-southwest of Cabo Corrientes, in Mexico’s state of Jalisco. It was heading west-northwest at 10 mph.

It is expected to approach Baja California Sur, Mexico, on Monday. The State Department, citing forecast models, said the storm is expected to weaken to a Category 1 storm before making landfall in northern Baja California Sur on Monday, and then will continue northeast into southern Sonora.

The National Hurricane Center said the storm will remain a “powerful hurricane” as it approaches land.

Polo could produce 4 to 8 inches of rain, and up to a possible 10 inches, across parts of Baja California Sur, the hurricane center said, cautioning that the rain “may produce life-threatening flooding and mudslides, especially in areas of steep terrain.”

Polo-generated swells will affect the southwestern Mexican coast over the next couple of days, spreading north along the west-central coast and the Baja California peninsula through the weekend, the hurricane center said, warning that swells are “likely to cause life-threatening surf, rip currents, and coastal flooding.”

Mexican leaders ordered evacuations, opened shelters and deployed military troops to areas that could be affected by the storm.

Classes were suspended at schools across the city of Acapulco, along the coast of Guerrero, its municipal government announced. Shelters across the state remained open, and officials said they were coordinating with local and national authorities to prepare for additional impacts of the hurricane.

Michoacán authorities also canceled classes through Friday in municipalities along the coast, urging residents of those areas not to leave their homes unless it was essential.

Polo’s extreme rapid intensification

Polo underwent what’s called extreme rapid intensification, in which a storm’s wind speeds increase by 58 mph or more over the course of 24 hours, between Monday and Tuesday. 

Its intensification was dramatic even by those standards, with winds that skyrocketed from 45 mph early Monday morning to 150 mph at around the same time the following day. The hurricane center described the storm’s transformation as “truly remarkable.”

Its maximum sustained winds climbed as high as 180 mph at one point, far exceeding the 157 mph threshold for Category 5, the strongest on the hurricane scale. By Saturday morning, the maximum sustained winds had lowered to near 160 miles per hour, with some higher gusts. 

Polo’s central pressure — an indicator of its strength and potential destructiveness — made it the second-strongest hurricane on record in the Eastern Pacific, behind 2015’s Hurricane Patricia. The storm’s wind speeds tied 2009’s Hurricane Rick as the third-strongest on record for the region.

Unusually strong El Niño conditions this year have been amping up tropical cyclone activity in the Pacific, with warmer waters, moist air and less wind shear enabling storm formation.