Marine Weather and Tide Forecast for Mill Valley, CA

SHORT TERM
Issued at 151 AM PST Mon Nov 10 2025 (Today and tonight)

There is a southerly surge in place along the coast, but knowing exactly how far north it has gone is impossible to determine as high clouds block the satellite imagery north of Monterey Bay. The weather station at Marina reported fog earlier tonight, Watsonville reported fog yesterday evening, but Half Moon Bay has not reported fog at any point so far tonight. This southerly surge will bring the potential for fog to the immediate coastal regions. Drivers along the Pacific coast south of the Golden Gate should be aware of potential rapid changes in visibility. If caught in dense fog, slow down, use low-beam headlights, and leave extra space in front of you.

For the rest of the region, high clouds tonight will limit radiational cooling over the Bay Area, and combined with light offshore flow in the higher elevations, will keep the low temperatures this morning slightly warmer than yesterday at around the middle to upper 50s. The interior Central Coast remains clear and the Salinas Valley could see lows dip into the lower 50s. In the higher elevations, the thermal belts remain active with lows in the lower to middle 60s. One more day of warm and dry conditions is expected today, with highs around 10 to 20 degrees above seasonal averages away from the immediate coast. Forecast highs are in the lower to middle 80s across the inland valleys, with the warmest spots of southern Salinas Valley and the Morgan Hill-Gilroy area reaching the upper 80s, the upper 70s to the lower 80s near the Bays, and the upper 60s to lower 70s near the Pacific coast.

LONG TERM
Issued at 151 AM PST Mon Nov 10 2025 (Tuesday through Sunday)

On Veteran's Day (Tuesday), the upper level ridging responsible for the warm temperatures begins to erode and shuffle to the east, starting a cooling trend that will bring highs down around 2 to 5 degrees across the region, with the most pronounced cooling at the coastal areas. This still leaves the highs anywhere between 5 to 15 degrees above seasonal averages across the region. Given the rest of the forecast involves unsettled weather, Tuesday is really the last day to make any preparations to prevent roadway flooding or water damage.

By Wednesday, a deep upper level trough permits a corridor of subtropical moisture to develop and approach the state of California. Yes my friends, this is an atmospheric river, but we aren't expecting days of intense rainfall. The really intense rainfall from this system is expected to come through late on Wednesday into Thursday, this being the time that the main rain band with the subtropical tap comes through the region. We are at the stage where we could start talking about lower confidence rainfall totals for the region. The initial estimates suggest that the Bay Area should see and Monterey Bay region should receive around an inch to an inch and a half of rainfall, with less rainfall within the rain shadowed valleys (perhaps significantly less rainfall), while the coastal ranges lean towards rain totals from 1.5 to 3 inches. Southerly winds will also increase as the storm approaches, and although the exact details are still to be refined, widespread gusts of 30 to 40 mph are possible with stronger gusts along the coast and at the higher elevations, especially through favored gaps and passes. We are also maintaining a 10-15% chance of thunderstorms as the main rain band passes through Wednesday night into Thursday.
The ECMWF and GFS models are putting K-Index values of 30 to 35 degrees Celsius, suggesting that scattered thunderstorms are possible. Over the next couple of days, high resolution mesoscale models will start to capture the system, and they will really help us narrow down the details of the incoming storm. This is especially critical in our part of the world, where the local terrain can significantly influence the weather impacts, terrain that is very often smoothed out in the global weather models.

Lingering showers continue after the main rain band passes through Friday before a lull in the rain on Saturday. A second trough will bring another period of rain chances next Sunday into the early part of the following week, with the details way too early to be teased out at this time. Through all of this, the temperatures will drop like a stone on Wednesday, bottoming out at the middle 50s to lower 60s for the lower elevations on Thursday and Friday.

AVIATION
(06Z TAFS)
Issued at 919 PM PST Sun Nov 9 2025

Ample high clouds streaming overhead making it hard to track the progress of the southerly surge. Have delayed CIGS for KHAF and KSNS as they have not materialized yet. Elsewhere, VFR with diurnal winds developing and drier offshore flow. KMRY,KSNS,KHAF have the best chance for cigs tonight and early Monday. Nailing down wind direction is lower confidence given the lack of stronger synoptic forcing.

Vicinity of SFO...Light winds with high clouds. Stronger onshore push Monday afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Lower cigs have entered MRY Bay, but not making it inland just yet. High clouds may be limited cool and inland intrusion of clouds. When clouds do move inland they'll be shallow with low cigs likely under 1k feet.

MARINE
(Tonight through next Saturday)
Issued at 919 PM PST Sun Nov 9 2025

Southerly flow continues to surge north along the Central coast bringing low clouds and locally dense fog with shifting winds.
Areas of north of the Golden Gate will remain light to moderate winds and out of the north. Southerly surge ends Monday with northerly flow all waters. Unsettled weather returns midweek with increasing southerly winds. These winds, combined with a building NW swell, will generate rough seas across the waters. Winds are expected to decrease Friday, but the larger swell continues to build with seas up to 15 feet before diminishing through the weekend.

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