Marine Weather and Tide Forecast for Boulder Creek, CA

SHORT TERM
Issued at 1152 PM PDT Fri Oct 9 2026 (Tonight through Sunday)

Much cooler air quickly flowed inland Friday with about equally weighted northerly ACV-SFO and onshore SFO-SAC pressure gradients supporting northwest winds. Current 24 hour temperature trends remain sharply lower by up to double digits Fahrenheit across higher elevations and inland. Surface temperatures across the highly varied terrain in our forecast area show only a few places left at highest elevation that are still relatively mild from the mid 60s to lower 70s. Due to a pattern shift with upper level troughing forecast to dominate our weather through the weekend, the lower level temperature inversion is already steadily weakening and lifting. The marine layer depth continues to increase, currently between ~ 1700 and 2500 feet. Cooling applied to the marine layer with upsloping winds will produce light patchy drizzle from San Francisco southward to the Big Sur coastline, including the East Bay hills tonight and Saturday morning.

Cold air advection continues through Saturday greatly weakening the lower level temperature inversion that's capping the marine stratus. Expect plentiful vertical mixing with drier air and daytime surface heating to mix out the stratus by early afternoon.

Highs and lows Saturday and Sunday will be below to much below normal for the time of year. Highs in the 60s/70s, warmest inland.
Lows in the 40s/30s, coldest far inland valleys, except near 50 along the immediate coastline and bays.

LONG TERM
Issued at 1152 PM PDT Fri Oct 9 2026 (Sunday night through next Friday)

500 mb troughing will prevail with mainly drier air flowing southward across our forecast area early to mid next week. There may be a little light measurable shower activity in the southernmost forecast area later Sunday and Monday. However, recent NBM has trended drier to less than 0.10" liquid precipitation. 500 mb ridging will advance eastward over our forecast area mid to late next week, bringing a return to warmer daytime temperatures.

AVIATION
(06Z TAFS)
Issued at 929 PM PDT Fri Oct 9 2026

The first half of the TAFs is focused on IFR-MVFR stratus developing and clearing. The second half of the TAFs is dealing with strong onshore winds. Currently STS, APC, HAF, MRY and SNS have IFR-MVFR ceilings, SFO and OAK may develop them for a few hours, and SJC and LVK are probably safe. A dry cold front coming from the north will bring drier air and strong onshore winds through the day Saturday.

Vicinity of SFO...While there is still a chance for ceilings overnight, the current satellite loop shows a pretty good hole over the terminal that hasn't been shrinking at all. OAK has a better chance of ceilings. The forecast is far from certain, however, as the SW winds will shift to a more westerly direction as the front approaches tonight. That, combined with the deepening marine layer, brings a chance for stratus to reach the terminal through the San Bruno Gap. On the other hand, the air behind the cold front is more dry, and the stronger winds should help mix out the lingering low-level moisture. Winds will increase through the day Saturday, with gusts up to 30 kts expected in the afternoon and early evening.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals.. MVFR ceilings are likely to persist through the night before clearing sometime around 18Z. The winds won't be as strong as the SF Bay Area.

MARINE
(Tonight through next Thursday)
Issued at 929 PM PDT Fri Oct 9 2026

Conditions are dangerous across the coastal waters this weekend.
Strong NW winds have arrived in the northwestern outer waters and will spread south through the night as a cold front moves through.
Frequent gale force gusts are expected in exposed waters. Rough to very rough seas will build in response to the strong winds. On top of the hazardous winds and rough wind waves, 2 sets of swell arrive this weekend, from both the south and west. The significant wave height will reach 15 feet in the outer waters.

BEACHES
Issued at 446 AM PDT Fri Oct 9 2026

Hazardous beach conditions will be present at Pacific Coast beaches Saturday through Monday. Long period southerly swell from distant Tropical Storm Rachel will build in height through the weekend, bringing an increased risk of sneaker waves and strong rip currents.
Long period westerly swell from a gale force low in the Central North Pacific will arrive Sunday, bringing breaking waves up to 16 feet. The large tidal swings will also result in coastal erosion as water and waves are brought farther up the beach than normal, especially during high tide. Remain off jetties, piers, rocks, and other waterside infrastructure as waves can sweep across the shoreline without warning, pulling people into the sea. Remain out of the water to avoid hazardous surf and strong rip currents and never turn your back on the ocean!

Sarment

MTR WATCHES/WARNINGS/ADVISORIES
CA...Coastal Flood Advisory until 3 PM PDT Tuesday for CAZ006-508-529- 530.

Beach Hazards Statement from 7 AM PDT Saturday through Monday evening for CAZ006-505-509-529-530.

Coastal Flood Advisory until 4 PM PDT Wednesday for CAZ506.

PZ...Small Craft Advisory until 3 PM PDT Sunday for Pigeon Pt to Pt Pinos 10-60 NM-SF Bay N of Bay Bridge.

Small Craft Advisory from 9 AM Saturday to 9 AM PDT Sunday for Mry Bay.

Gale Warning until 9 PM PDT Saturday for Pt Arena to Pt Reyes 0- 10 nm.

Small Craft Advisory from 3 AM Saturday to 9 AM PDT Sunday for Pt Reyes to Pigeon Pt 0-10 nm.

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

Gale Warning until 9 AM PDT Sunday for Pt Arena to Pt Reyes 10- 60 NM.