Millions across the Pacific Coast of Mexico are bracing as a monster storm closes in.

A powerful Category 3 hurricane is zeroing in on Baja California, warning of life-threatening flash floods, flattening winds and massive surf as it barrels toward landfall in the coming hours.

Hurricane Polo, packing sustained winds near 115 mph, is forecast to slam into the west coast of Baja California Sur late this afternoon or evening, per the National Hurricane Center.

The storm is expected to remain near major hurricane strength at landfall before weakening as it tears across the rugged peninsula and pushes inland toward mainland Mexico late Monday or early Tuesday.

Residents in fishing villages like Puerto San Carlos are already boarding up homes and hauling dirt and rubble to reinforce embankments against high tides and pounding waves.

Mexico’s official emergency management and disaster-response system Civil Protection has urged evacuations from high-risk coastal zones, with many families heading inland to shelters in towns and cities such as Ciudad Constitución.

In-person classes have been suspended at schools across Baja California and Sonora.

Forecasters warn of 6 to 12 inches of rain across parts of Baja California Sur, raising the risk of deadly flash flooding and mudslides, especially where terrain is steep. Storm surge and large, destructive waves are also expected along the Pacific coast.

After crossing Baja, Hurricane Polo is projected to make a second landfall in southern or central Sonora late tonight or early Tuesday before rapidly weakening over land.

For Southern California, the immediate threat is high surf and strong rip currents along Southern California beaches as swells generated by the storm roll north.

Tropical moisture from Polo is also expected to fuel heavy rain and threaten coastal flooding across parts of the US Southwest later today through Tuesday.

The Mexican navy has stationed personnel and aid in Pacific ports including Guaymas and Mazatlan, while soldiers have set up shelters in remote, vulnerable communities like San Juanico.

The National Hurricane Center is urging residents in the path of the storm to complete preparations immediately, as conditions are expected to deteriorate rapidly through the day.

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