American Canyon, CA 94503 Weather

: New AVIATION, MARINE:

Key messages

Updated at 1227 AM PDT Wed Oct 28 2026

- Moderate coastal flooding at high tide for Bayshore and Pacific Coast locations through the week

- Seasonal to slightly below seasonal temperatures through the extended forecast

- Potential for rain this weekend and again early to mid next week

Short term

Issued at 1227 AM PDT Wed Oct 28 2026 (Today and tonight)

Satellite imagery shows lingering high clouds over Monterey and San Benito Counties with patches of stratus along parts of the higher elevations. Some stratus expansion is possible through the morning with some clearing after sunrise, but high level clouds will also arrive this morning and persist into the evening hours and beyond.

Conditions remain cool and dry as large scale troughing persists and expands, with a cut-off low over British Columbia and a decaying low crossing over from the Central Pacific merging to help dig the trough axis deeper into California. Morning lows hover in the upper 30s to the middle 40s across the inland valleys, into the middle 30s for the coldest spots in the eastern Santa Clara and interior Central Coast mountains, and the upper 40s to lower 50s near the coasts. Highs will remain cooler than the seasonal averages with high temperatures in the upper 60s to lower 70s inland, the middle 60s to near 70 along the Bayshore, and the upper 50s to lower 60s at the immediate coast. Winds will remain relatively light with a gentle onshore push expected in the afternoon and evening hours. Wind gusts might reach 20 mph along favored coastal areas and through favored gaps and passes.

A combination of high astronomical tides and surge from thermal expansion effects brings the risk of minor coastal flooding along the Bayshore at the San Pablo, San Francisco, and Monterey Bays, and the Pacific coast, at high tide today. At the San Francisco tidal gauge, high tide is expected to be 1.9 ft above normal (7.7 ft MLLW) at 12:56 PM Wednesday 10/28, including around 1.2 ft of surge residual partially attributed to impacts from El Nino.

Long term

Issued at 1227 AM PDT Wed Oct 28 2026 (Thursday through Tuesday)

Troughing will continue to impact the region at least into the upcoming weekend, with high temperatures dipping into the middle 60s to lower 70s inland and the upper 50s to lower 60s near the Pacific coast and the Bays. Gloomy and cloudy conditions continue into Friday. The chances for rain continue to be rather low during the Halloween weekend, with probabilities of precipitation around 10 to 30% throughout the Bay Area and Central Coast. Rainfall totals, assuming rain does come, will remain on the beneficial side with the latest forecast showing a few hundredths of an inch across the southern halves of Monterey and San Benito Counties and zero accumulating precipitation everywhere else. Even the reasonable worst case scenario, one with a 10% probability that rain totals will end up above the scenario, ranges from around a tenth of an inch in the North bay to a half to three quarters of an inch for interior Monterey and San Benito Counties.

Once we cross into the early part of next week, the meteorological uncertainty really ratchets upwards. The current forecast shows chances for rain continuing into the end of the 7-day outlook, but merely looking at some of the models, say, the deterministic European model or the European ensemble mean, would leave the untrained user scratching their heads trying to reconcile that forecast with the ridge that these models depict over the West Coast. Setting aside the fact that this is where the model reliability begins to degrade, especially for the deterministic models, there are a few things that are going on here. The first is that the deterministic models are depicting the formation of a cut- off low in the central Pacific, and cut-off lows are notoriously difficult to accurately predict as they can isolate themselves from the large-scale flow. Indeed, the American GFS model depicts this cut-off low coming closer to the state around this time. Looking at ensemble model cluster analysis will support the high uncertainty as there's not really a dominant scenario out of various solutions on how fast the cut-off low will come into the Western United States, and indeed it looks like the speed of the low is the main factor in creating the uncertain ensemble space. Or in layman's terms, there are chances for rain next week, but when the rain actually arrives is up in the question, and that is before we try to find out where in the state the rain will actually be the heaviest. Keep checking back with us for more details:

Coastal flooding concerns continue across Bayshore locations within the San Pablo, San Francisco, and Monterey Bays through Saturday and the Pacific coastal regions through Friday. At the San Francisco tidal gauge, high tide is expected to be 1.9 ft above normal (7.7 ft MLLW) at 01:43 PM Thursday 10/29, 1.6 ft above normal (7.4 ft MLLW) at 02:39 PM Friday 10/30, and 1.1 feet above normal (6.9 ft MLLW) at 03:44 PM on Saturday 10/31, including around 1.2 ft of surge residual partially attributed to impacts from El Nino.

Aviation

(12Z TAFS) Issued at 434 AM PDT Wed Oct 28 2026

VFR will persist through the forecast period with the exception of some patchy dense fog in the valleys of the North Bay.

Vicinity of SFO: VFR with light and variable winds this morning with westerly prevailing winds developing this afternoon and evening.

SFO Bridge Approach: Similar to SFO.

Monterey Bay Terminals: VFR with light and variable winds becoming onshore out of the west this afternoon and evening. Light offshore flow at times develops again later tonight.

Marine

(Today through Monday) Issued at 434 AM PDT Wed Oct 28 2026

Moderate to strong northwest winds continue today across the outer waters with fresh to moderate breezes along coastal waters, with seas continuing to build in response and resulting in rough seas over exposed waters. Expect gradually improving conditions by Thursday.

Watches, warnings and advisories

CA: Coastal Flood Advisory until 6 PM PDT Saturday for CAZ006-506- 508-529-530.

Coastal Flood Advisory until 5 PM PDT Friday for CAZ505-509.

PZ: Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this evening for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

Small Craft Advisory until 9 PM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.

Small Craft Advisory until 3 PM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM.