Seattle Weather Bureau warns of minor coastal flooding in western Washington
Tidal overflow could submerge low-lying areas by two feet in San Juan County and western Whatcom County zones during Wednesday morning high tides.
By Marina Weber ·
The National Weather Service Seattle office issued a coastal flood advisory on Tuesday, November 10, 2026, for the following morning. The warning targets specific coastal zones in western Washington where rising tides may inundate low-lying ground.
Minor coastal flooding is expected between 5 AM and 11 AM Pacific Standard Time on Wednesday, November 11. The advisory covers San Juan County and the lowlands of western Whatcom County. Officials project that water levels will rise 1.5 to 2 feet above the Mean Higher High Water mark in these areas.
The primary cause is tidal overflow during high tide. This phenomenon may flood parking lots, parks, and roads. While isolated road closures are anticipated, the weather bureau advises drivers to allow extra time for travel. Travelers are instructed not to drive around barricades or through water of unknown depth.
The advisory defines inundation height relative to the Mean Higher High Water level. This metric indicates the vertical distance water will cover the ground surface. The weather bureau encourages residents to monitor local tide tables and air quality readings. These data points help individuals in flood-prone property areas prepare for the event.
The office recommends protecting assets in vulnerable locations before the tide peaks. The advisory remains in effect for the specified six-hour window. No other severe weather phenomena accompany this coastal flooding warning.
