Marine Weather and Tide Forecast for Danville, CA

SHORT TERM
Issued at 132 PM PDT Sun Mar 8 2026 (Tonight through Monday)

High pressure aloft that has been nosing over our service area the last couple days is slowly weakening while retreating out to sea.
This has allowed for weak upper ridge axis to establish just off the coast with a weak thermal trough surface reflection. This thermal trough will be fairly short lived, but is has allowed weak offshore flow to remain just a little longer than expected. As the afternoon ticks on the ridge will continue to retreat, eroding the offshore thermal trough. Heating across the land areas will generate another thermal through and help to induce onshore flow to develop. This has already begun in some areas. Onshore flow will impact all regions of our service area by early this evening.
As a result, expect low clouds and some patchy fog to develop this evening and overnight. This marine layer should be about 1000-1500 feet in depth and should erode fairly quickly tomorrow morning as weak offshore winds at 925 mb develops for a short time. After the morning low clouds and fog erode, Monday will be another nice day, but on the cooler side. Relative to what we've had of course.
Temperatures will drift towards climatology the next couple days.
As part of this gentle pattern shift, we'll see a weak dry boundary (seen in OPC charts) come into the area on Monday. Given that high pressure remains anchored and stout over the Eastern Pacific, low pressure over us means a tightening pressure gradient over the coastal waters. In turn, this means increasing winds out of the Northwest for Monday. Look for breezy conditions along the coast and the coastal mountains through the day on Monday.

LONG TERM
Issued at 132 PM PDT Sun Mar 8 2026 (Monday night through next Saturday)

Monday night will bring another night of low clouds and fog for the service area. Tuesday will be the closest we get to seasonal normal temperatures as a broad upper trough passes just North of the area. On the backside of the upper trough another upper ridge will build. Unlike the last one with a West <-> East orientation, the one building midweek will have a classic North-South ridge axis. This will bring rapidly warming temperatures to our entire area with the highest temperatures in East and South Bays and the Central Coast. While models are consistent with the warm up, the closer to water, the wider the spectrum of solutions. Inland locations have fairly tight spreads of probabilities. In general Wed-Fri, models have spread of temperature from the mid 70s to the upper 80s, depending on location. Temps should moderate next weekend as the ridge retreats slightly before building back stronger the week of the 15th. The next shot at any liquid water falling from the sky won't be until the last week of March and into April. By that point the odds of receiving beneficial amounts starts to plummet. As of Sat 7 Mar, our service is standing about 75-125% of normal on the water year, which began 1 Oct 2025.

AVIATION
(18Z TAFS)
Issued at 1054 AM PDT Sun Mar 8 2026 VFR will be the story of Sunday. At least most of it. Winds will be shifting from offshore to onshore late this morning into the afternoon, which will give a path for low level moisture to work its way back into the Bay Area and Central Coast. Expect low cigs and some local reduction in vsby for a time overnight. Clearing on Monday should occur mid to late morning.

Vicinity of SFO...VFR. Weak winds from the NE will shift and come from the NW over the next couple hours. This will allow for the marine layer to start working its way into the area. Expect low clouds and possible vsby reduction overnight as the marine layer settles in. Clouds are expected to clear out mid Monday morning, around 10 AM.

SFO Bridge Approach...Similar to SFO. It'll take another hour for the clouds to develop overnight and will clear out about an hour earlier than SFO proper.

Monterey Bay Terminals...VFR today. Onshore flow will develop today which will increase humidity levels through the day. Look for clouds to start developing late afternoon into the early evening. Clouds could make a showing at the surface causing some local reductions in vsby. Clearing should occur by mid morning Monday.

MARINE
(Today through Friday)
Issued at 848 AM PDT Sun Mar 8 2026

Conditions will rapidly deteriorate tonight into Monday as gales develop. Expect very rough conditions into Tuesday. San Francisco Bay and Monterey Bay are expecting rough conditions on Monday.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory from 3 PM Monday to 3 AM PDT Tuesday for Mry Bay.

Small Craft Advisory until 3 AM PDT Tuesday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory from 9 PM this evening to 3 AM PDT Tuesday for Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory from 9 AM Monday to 3 AM PDT Tuesday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

Small Craft Advisory until 3 PM PDT this afternoon for Pt Arena to Pt Reyes 10-60 NM.

Gale Warning until 3 AM PDT Tuesday for Pt Arena to Pt Reyes 10- 60 NM.

Small Craft Advisory from 9 PM this evening to 3 AM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM.

Gale Warning from 3 AM Monday to 3 AM PDT Tuesday for Pigeon Pt to Pt Pinos 10-60 NM.