SAN FRANCISCO — A coastal flood advisory begins Saturday morning along the San Francisco Bay shoreline and lasts through Thursday afternoon as a run of unusually high tides combines with a forecast surge.
The National Weather Service says up to 1.9 feet of inundation above ground level is possible in low-lying shoreline and tidal-waterway locations. The agency warns of isolated road closures, flooded low-lying infrastructure and coastal erosion.
What time are the high tides in San Francisco?
| Date | SF tide-gauge time | Forecast level |
|---|---|---|
| Sat. Oct. 24 | 10:39 a.m. | 6.9 ft MLLW · 1.1 ft above normal |
| Sun. Oct. 25 | 11:07 a.m. | 7.2 ft · 1.4 ft above normal |
| Mon. Oct. 26 | 11:39 a.m. | 7.5 ft · 1.7 ft above normal |
| Tue. Oct. 27 | 12:15 p.m. | 7.6 ft · 1.8 ft above normal |
| Wed. Oct. 28 | 12:56 p.m. | 7.7 ft · 1.9 ft above normal |
| Thu. Oct. 29 | 1:43 p.m. | 7.5 ft · 1.7 ft above normal |
NWS says those predictions include up to 1 foot of surge on top of the astronomical tide. Tide timing can vary by as much as roughly 90 minutes earlier or later along the Pacific coast and through San Francisco Bay.
Which parts of San Francisco are under the advisory Saturday?
The Saturday-start advisory covers Bay shoreline locations, including low-lying areas along San Francisco Bay. It should not be read as saying every San Francisco neighborhood faces flooding.
A separate NWS advisory for the San Francisco Peninsula Coast begins at 9 a.m. Monday, Oct. 26 and runs through 3 p.m. Thursday. That distinction matters for Ocean Beach and other Pacific-facing areas.
When is the flood risk highest?
The forecast tide rises each day through Wednesday, when the San Francisco gauge is projected to reach 7.7 feet MLLW at 12:56 p.m. The advisory remains in place Thursday because the projected tide is still unusually high.
Impacts are most likely around the daily high-tide window rather than continuously for all six days.
What should drivers and shoreline visitors know?
NWS says some roads may close and warns drivers not to go around barricades or through water of unknown depth. Rising tides can also push water and waves farther up beaches than normal, making escape routes from coastal areas more difficult.
Anyone with flood-prone property near the shoreline should use the advisory as a prompt to prepare before the highest tides arrive.