By Sam Mauhay-Moore, SFGate, San Francisco The Tribune Content Agency
Some of the highest tides of the year are expected to impact the Bay Area this week, prompting the National Weather Service to issue a flood advisory for the region's coastal areas.
The high end of this week's king tides is expected to peak shortly before 11 a.m. Saturday, though the advisory remains in effect until 4 p.m. Monday. Flood advisories were issued for coastal areas from Big Sur to Point Reyes, including interior valleys in the North Bay and shorelines along the San Francisco Bay. Northwest-facing beaches and shorelines are most at risk of flooding, according to the weather service.
"The main impacts we're really worried about are what happens at the high tide, when the water gets into places like roads or sidewalks or parking lots that might impact people trying to get to and from the coastal regions," weather service meteorologist Dial Hoang said.
Parking lots, parks and roads in coastal areas are expected to flood through Monday, necessitating some road closures, according to the weather service. The agency recommends that commuters allow extra time for travel and avoid driving around barricades or through high water.
King tides, also known as spring tides, occur when the ocean's gravitational pulls are highest during a full or new moon. These gravitational pulls result in both the lowest low tides and, in this week's case, the highest high tides of the year, as water levels shift to reflect the alignment of the Earth with the sun and moon.
Along with the flood advisory, the weather service issued a high surf advisory for coastal areas from Thursday through Saturday as large waves, strong currents and turbulent shore breaks are expected to create unsafe swimming and surfing conditions. Breaking waves between 12 and 15 feet tall will hit northwest-facing beaches through Saturday.
The effects of this week's king tides come as the Bay Area experiences its first widespread rain event of the season. Scattered showers will impact the region throughout the day Thursday before tapering off in the evening, Hoang said.