A natural coast rhythm around the winter solstice is bringing the year's highest tides to California shores.
Mark Strudley of the National Weather Service in Monterey said that he expects high tidal activity through Tuesday. He said it will peak Monday, with the likelihood of flooding at low-lying areas.
Strudley says the so-called King Tide happens when the sun and moon align, which pulls ocean water to opposite sides of the earth and creates extremely high and low tides.
Flooding was reported in a Mill Valley parking lot on Sunday.
Capt. Greg Stump, commander of the Coast Guard Sector San Francisco, says swells could rise to around seven feet.
He warns marinas and boat owners to check their moorings and to be careful.