A massive “planetary wave” stretching thousands of miles across the Pacific Ocean is making its way toward Northern California, where oceanographers predict it will temporarily raise sea levels by nearly one foot along the coast and throughout the San Francisco Bay Area.

Driven as a direct consequence of the strengthening Super El Niño, this phenomenon—known scientifically as a Kelvin wave or coastally trapped planetary wave—is moving northward from Equatorial Central America at around 6 mph.

Unlike surf swells that break violently along the shore, planetary waves are imperceptible to the naked eye.…