The National Weather Service issued coastal flood warnings and advisories for shoreline communities across Southern and Northern California through October 29, 2026. Forecast high tides and elevated water levels could inundate low-lying roads, parking areas and waterfront infrastructure, with the greatest concerns involving vulnerable coastal locations in San Diego, Orange County and the San Francisco Bay Area.
Key Takeaways
- A Coastal Flood Warning covers the San Diego and Orange County coasts through October 29, according to the reported forecast.
- Coastal Flood Advisories extend across parts of Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties.
- San Francisco Bay water levels are forecast to reach as much as 1.9 feet above normal on October 28.
- Potential impacts include road closures, saltwater inundation, beach erosion and restricted access to coastal facilities.
- A separate advisory identifies possible flooding near vulnerable shoreline areas and tidal waterways in Humboldt County.
Coastal Flood Warnings Cover Southern California Shorelines
California coastal flood alerts issued by the National Weather Service cover shoreline regions through October 29, 2026, with high tides and elevated water levels threatening vulnerable coastal areas. The alerts affect communities in Southern California, the San Francisco Bay Area and parts of the North Coast.
A Coastal Flood Warning covers the San Diego and Orange County coasts through 1 p.m. Pacific Daylight Time on October 29. Forecast water levels are 1 to 1.7 feet above astronomical tide predictions, with potential flooding affecting homes, businesses, critical infrastructure and roads.
Coastal Flood Advisories also cover portions of Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties, including Malibu, Catalina Island and the Santa Barbara Islands. Forecasters warn of possible seawater flooding around high tide, beach erosion and restricted access to parking lots, bicycle paths and harbor walkways. Isolated structural damage is possible in exposed locations.
Similar coastal hazards affected homes and public infrastructure during previous Southern California storm damage. The current forecasts describe a separate flooding risk, with potential impacts varying according to local water levels, shoreline exposure and the elevation of roads and properties.
High Tides Threaten Roads and Low-Lying Coastal Properties
Morning high tides are the main concern in Southern California, where water levels along the San Diego and Orange County coasts are forecast to reach 1 to 1.7 feet above astronomical tide predictions. Flooding remains possible even without elevated surf, particularly in low-lying areas near the shoreline.
In the Los Angeles and Oxnard forecast area, late-morning high tides are expected to reach 7.5 to 8 feet above Mean Lower Low Water, about 1 to 1.5 feet above astronomical projections. The highest tides are forecast from October 26 through 28, with a small chance of isolated Coastal Flood Warnings on October 28 and 29 if larger surf develops.
Potential impacts include seawater reaching coastal roads, parking facilities, bicycle paths and harbor walkways. Flooding could affect homes, businesses and critical infrastructure, while beach erosion and localized structural damage may occur in exposed locations. Road closures could also disrupt travel through vulnerable coastal areas.
Earlier San Francisco Bay sea-level measurements recorded high tides about 1.5 feet above predictions on October 10 and 11. Those measurements relate to an earlier event, not the current forecast. Actual flooding during the current alerts will depend on local ground elevations and coastal conditions.
San Francisco Bay Forecast Shows Elevated Water Levels
The National Weather Service has issued Coastal Flood Advisories for shoreline areas around San Pablo Bay, San Francisco Bay and Monterey Bay through 3 p.m. PDT on October 29. A separate advisory for the Coastal North Bay, including Point Reyes National Seashore, and the San Francisco Peninsula coast began at 9 a.m. on October 26 and runs through the same end time.
San Francisco tide-gauge forecasts show water levels above normal through October 29. High tides are forecast at 11:39 a.m. on October 26, reaching 7.4 feet above Mean Lower Low Water, and at 12:15 p.m. on October 27, reaching 7.6 feet. The forecast peaks on October 28 at 7.7 feet, then reaches 7.5 feet on October 29.
The forecasts include up to 1 foot of surge. High-tide timing may vary by location, occurring as much as 90 minutes earlier along parts of the Pacific coast or later within San Francisco Bay. Forecasters attribute the flood threat to astronomical high tides and higher water levels associated with warm-water expansion during El Niño.
Potential impacts include inundation in low-lying shoreline areas, infrastructure flooding, road closures, beach erosion and reduced beach access. The risks also relate to California’s winter flood preparations, although the current advisories identify specific coastal areas and high-tide periods rather than uniform flooding across the state.
Humboldt Bay Advisory Identifies Localized Flooding Risks
Northern California faces a separate coastal flooding concern around Humboldt Bay. The National Weather Service’s Eureka forecast office issued a Coastal Flood Advisory for Northern Coastal Humboldt County from 10 a.m. to 2 p.m. Pacific Daylight Time on October 26.
The forecast identifies possible saltwater inundation of up to 0.5 feet near vulnerable shorelines and tidal waterways. The North Spit tide gauge is forecast to reach between 8.9 and 9.2 feet above Mean Lower Low Water, with high tide expected at 11:58 a.m.
Potentially affected locations include Jackson Ranch Road in the Arcata Bottoms and roads in King Salmon. These locations face a more localized advisory than the warning covering the San Diego and Orange County coasts.
The Humboldt Bay forecast adds a North Coast component to the statewide pattern of coastal alerts. The specific expected water levels and advisory periods differ by forecast area, so conditions in Humboldt County should not be treated as identical to those in Southern California or the San Francisco Bay Area.
Flooding can create access problems for residents and businesses near tidal waterways, particularly where roads sit at low elevations. The forecast identifies possible impacts rather than confirming that every listed location will flood.
California’s emergency response preparations include statewide flood rescue equipment upgrades for specialized swiftwater rescue teams. Those upgrades are intended to support responses to hazardous water emergencies, including flooding and fast-moving water. They are separate from the coastal flood alerts and do not indicate that rescue deployments are required in the areas covered by the current advisories.
National Weather Service Forecasts Guide Coastal Preparedness
The alerts identify periods when elevated tides could affect exposed coastal locations, including roads, parking areas, harbor walkways and other low-lying infrastructure. The forecast periods extend through October 29 in several regions, although the Humboldt County advisory described in the report applies specifically to October 26.
The timing of high tide is a key detail for communities and people using shoreline facilities. In San Francisco, for example, the forecast places the highest listed water level on October 28, while Southern California’s highest tides are expected between October 26 and 28.
The difference between a Coastal Flood Warning and a Coastal Flood Advisory also matters when interpreting the alerts. The San Diego and Orange County warning identifies a more serious anticipated flooding threat, while advisories in other regions describe potential impacts that vary by location and forecast conditions.
The National Weather Service’s regional forecast offices provide location-specific information for communities covered by the alerts. Their updates are the relevant source for checking changes to warning periods, expected water levels and the areas affected.
Frequently Asked Questions
Which California counties are under coastal flood warnings or advisories?
The reported alerts cover San Diego and Orange counties, as well as portions of Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties. Additional advisories cover parts of the San Francisco Bay Area, the central coast and Northern Coastal Humboldt County.
How long are the California coastal flood alerts expected to remain in effect?
Several coastal warnings and advisories are scheduled to continue through October 29, 2026. The Humboldt County advisory described in the report applies from 10 a.m. to 2 p.m. on October 26.
How high are tides forecast to rise above normal in San Francisco Bay?
The San Francisco tide-gauge forecast lists a departure from normal of up to 1.9 feet on October 28. The forecast water level for that date is 7.7 feet above Mean Lower Low Water.
Which coastal areas face potential high-tide flooding?
Vulnerable locations include low-lying shorelines, tidal waterways, coastal roads, beach parking lots, bicycle paths and harbor walkways. The reported forecasts also identify potential flooding near Jackson Ranch Road in the Arcata Bottoms and roads in King Salmon.
What types of infrastructure could be affected by coastal flooding?
Potential impacts include flooding of roads, homes, businesses and critical infrastructure, along with restricted access to coastal facilities. Shoreline erosion and isolated structural damage are also possible in exposed areas.
