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Updated:September 30, 2026 9:00 am PDT

Coastal Flood Advisory COASTAL FLOOD ADVISORY  
Alameda County

  Effective: Tue, 9/29 2:54pm Severity: Minor
  Updated: September 30, 2026 9:00 am Urgency: Expected
  Expires: Wed, 9/30 4:00pm Certainty: Likely

Areas Affected: San Francisco - North Bay Interior Valleys - San Francisco Bay Shoreline - Northern Monterey Bay - Southern Monterey Bay and Big Sur Coast
 
Alert Details:
* WHAT...Up to 1.2 ft of inundation above ground level is
possible in low-lying areas near shorelines and tidal
waterways.

* WHERE...Bayshore locations along the San Francisco Bay, San
Pablo Bay, and Monterey Bay.

* WHEN...Now through 5 PM PDT Thursday.

* IMPACTS...Flooding of lots, parks, and roads with only
isolated road closures expected. High tides will result in
flooding along coastal trails, cut off access to some low-
lying beaches and coastal areas, and bring water and waves
farther up the beach than typical.

* ADDITIONAL DETAILS...At the San Francisco tidal gauge, high tide
is expected to be 1.2 ft above normal (7.03 ft MLLW) at 2:10 PM
Wednesday 9/30, and 1.1 ft above normal (6.92 ft MLLW) at 2:58
PM Thursday 10/01. These predictions include up to 0.7 ft of
surge that will enhance the astronomical tide and flooding
threat. High tide varies up to 90 minutes earlier or later along
the Pacific Coast and through the San Francisco Bay,
respectively.

Information:
If travel is required, allow extra time as some roads may be
closed. Do not drive around barricades or through water of
unknown depth. Take the necessary actions to protect flood-prone
property.