Marine Weather and Tide Forecast for Sunol, CA

SHORT TERM
Issued at 1240 PM PST Sat Jan 17 2026 (This evening through Sunday)

Not much change this afternoon, similar to yesterday with fog lingering in the interior East Bay Valleys and the West Delta.
The most notable difference, is that we have high clouds moving from south to north across the region. We will continue to watch closely how these high clouds will affect afternoon temperatures, but largely should still be another warm day across much of the region this afternoon with high temperatures in the mid 60s to mid 70s (up to 80 degrees F in the higher terrain).

Tonight, look for fog (dense at times) to develop across the West Delta, North Bay Valleys, and interior East Bay Valleys that will linger into Sunday morning. Again, high clouds may limit overnight cooling by a few degrees making the fog forecast difficult. Offshore winds are forecast to decrease over the next 36 hours or so, and may allow for more cooling in the higher elevation tonight.

Looking for a near repeat for Sunday afternoon as high clouds will continue to stream across the region. Thus, temperatures will be similar to Saturday afternoon.

LONG TERM
Issued at 1240 PM PST Sat Jan 17 2026 (Sunday night through next Friday)

Little change in the long term forecast as a mid/upper level ridge of high pressure will remain in place just off of the West Coast through midweek. Thus, look for similar conditions as this weekend to persist. Late night and early morning fog across the West Delta, North Bay Valleys, and interior East Bay Valleys looks like a good possibility.

By late week, there is a potential weak short wave trough forecast to impact the region with chances for light rainfall Friday into Saturday. However, it is looking the region may just see an increase in cloud cover and return of cooler conditions (closer to seasonal averages). It isn't until late January we see the Climate Prediction Center show the region leaning above normal in their 8-14 Day Precipitation Outlook.

AVIATION
(00Z TAFS)
Issued at 351 PM PST Sat Jan 17 2026

Satellite shows high clouds over the region, with any signs of low cloud or fog found east of us and in the Valley.
Observations across the region depict VFR conditions with primarily light winds at the terminals. Expect this to generally continue through the evening hours for most sites. The question for tonight will be, does the high cloud limit fog development? Current thinking is that the North Bay terminals should see some conditions falter, especially at KSTS given their pattern the past week. For KAPC the and East Bay terminals, confidence is moderate to low given last night's reports and high clouds remaining in the forecast. Trended closer to MVFR to VFR conditions for these sites, should they see any fog development; however we'll need to keep an eye on them.
Tomorrow, any fog that does develop should clear by mid to late morning, with VFR conditions returning and high clouds lingering.

Vicinity of SFO...Quiet and VFR conditions, plus light offshore winds continue for much of the TAF cycle. Winds may go variable for a bit overnight but return to the east-northeast by tomorrow morning.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR conditions continue through the period.
KSNS should hold with offshore flow through this period, while KMRY observes onshore flow for the next few hours before becoming offshore once again.



MARINE
(Today through Thursday)
Issued at 837 AM PST Sat Jan 17 2026

Moderate to breezy northeast winds continue across the San Pablo Bay, the delta, and through the Golden Gate through the weekend while light northeast to north winds persist across the rest of the coastal waters. Light seas continue into early next week before the next round of long period swell arrives and brings light to moderate seas in the mid week.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...None.