Marine Weather and Tide Forecast for Monte Sereno, CA

SHORT TERM
Issued at 120 PM PDT Sun May 17 2026 (This evening through Monday)

Winds eased overnight but are starting to ramp again across the region but especially across the higher elevations. While winds were predominantly onshore over the last few days, this next round of wind will be offshore. Synoptically, a ridge of high pressure sits to our west over the Pacific Ocean while a positively tilted upper level trough moves into the Intermountain West. The orientation of these two features will promote North to Northeast winds across our region or offshore flow. The SFO-WMC gradient has largely been weakly positive (onshore) the last few days but is expected to become negative (offshore) and strengthen today into early tomorrow.
Current guidance has the SFO-WMC gradient peaking around -7 to -8 mb which supports gustier offshore winds. The SFO-ACV remains strong around -8 to -8.5 mb indicating good northerly flow will continue.
These winds will be strongest across the higher elevations of the North Bay, East Bay, South Bay, and Santa Cruz Mountains where gusts to around 50 mph and locally higher gusts up to 60 mph are expected this evening into tomorrow morning. The strongest winds are expected to occur overnight tonight through late tomorrow morning. A Wind Advisory is in effect from 11PM tonight through 11AM Monday for these locations. While not as strong as across the higher elevations, winds will still be breezier across the rest of the region. Guidance currently keeps winds gusting between 25 to 35 mph (below Wind Advisory criteria) but we may see a few stronger gusts mix down into the lower elevations at the base of mountainous terrain. Winds are then expected to diminish through the remainder of the day on Monday. High temperatures remain seasonably cool today in the 70s to low 80s across the interior and 50s to 60s along the coast. Slightly warmer temperatures are expected tomorrow with coastal temperatures in the 60s to low 70s and interior highs in the 70s to 80s.

Extremely dry conditions continue through midweek with elevated fire weather concerns across the interior Bay Area and Central Coast.
Daytime humidity values will be incredibly dry with the higher elevations dropping to between 10-15% today. A few fires have been reported across the interior this morning including the Pass Fire in Alameda County (Altamont Pass region). Fuels are expected to rapidly dry as strong offshore flow develops today into tomorrow which is likely to lead to an increase in grass fires. Take care while participating in any outdoor activities involving fire. Remember, one less spark, one less wildfire.

LONG TERM
Issued at 120 PM PDT Sun May 17 2026 (Monday night through next Saturday)

Broad upper level troughing will push eastward by midweek with high pressure generally restrengthening over the West Coast. The center of the ridge and surface high pressure looks to be farther north closer to the PNW while a weak upper level trough lingers over SoCal and Arizona. This setup would support a return on onshore (northwest) winds but they will not be as gusty as those experienced this weekend. The surface pressure gradient will be more widespread (i.e. not as tight) as it was this weekend and it will lose upper level support with the polar jet stream shifting northwards and the tropical jet stream shifting south. While the winds are dying down, temperatures are starting to warm up. The return of ridging and high pressure will allow a warming trend to kick off this week and see a return of 80s/90s to the interior and 60s/70s along the coast.
Patchy moderate heatrisk is expected across interior, urban areas this week with temperatures running around 10-15 degrees above normal. The question is how much of a marine influence will we see this week and will it be enough to keep our coastal areas/portions of the interior cooler this week. Right now, high resolution guidance keeps a shallow (500 ft) marine layer present through mid to late week which would keep its influence (fog, cooler temps) tied to more coastal areas.

AVIATION
(00Z TAFS)
Issued at 428 PM PDT Sun May 17 2026

Currently VFR at all terminals with the exception of haze being observed at HAF. High confidence in VFR through the TAF period; however, haze will reduce slant range visibilities. Strong and gusty onshore winds will veer tonight to become northerly/offshore with onshore flow returning tomorrow afternoon. Low level wind shear (LLWS) has been included in the TAFs starting between 03Z and 05Z this evening and continuing through 18Z tomorrow morning. The end time is pessimistic with most LLWS activity expected to occur once the atmosphere decouples tonight until it recouples tomorrow morning, probably closer to 15Z. LLWS is primarily expected between FL015 and FL020 with speeds of 35-45 knots out of the north/northeast.

Vicinity of SFO...Currently VFR with gusty westerly flow. High confidence in VFR through the TAF period. Winds will veer tonight to become northerly before returning onshore tomorrow afternoon.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with westerly flow at both terminals. High confidence in VFR through the TAF period. Diurnal winds are expected through the TAF period.

MARINE
(Tonight through next Friday)
Issued at 428 PM PDT Sun May 17 2026

Strong surface high pressure will remain nearly stationary over the eastern Pacific this week. This will result in widespread strong and gusty northwest winds across the coastal waters. Rough seas continue through late today with up to 19 ft waves during the strongest winds, but seas will ease into the work week.

FIRE WEATHER
Issued at 443 AM PDT Sun May 17 2026

Strong and gusty north to northwest winds continue to affect the region, shifting slightly into Sunday afternoon, and becoming north to northeast. Expect peak gusts greater than 30 mph for most areas, with around 45 to 55 mph along through gaps and passes, and across higher terrain. Daytime humidity retentions loos to stay around 10- 25% across the interior regions and higher peaks, with limited overnight humidity recoveries. Strong winds persist into the early Monday before diminishing. Humidities will be slow to recover into the work week as a light offshore flow will continue to affect the district.

BEACHES
Issued at 140 AM PDT Sat May 16 2026

A Beach Hazards Statement remains in effect for west facing beaches along the Pacific Coast through 9 AM Monday due to strong winds over the marine environment leading to hazardously strong wind waves and overall rough seas. Dangerous swimming, boating, and surfing conditions can be expected. Large breaking waves can overpower swimmers resulting in significant physical injury and increase the risk of drowning. Gusts will stay strong along the immediate coast, causing blowing and drifting sand and increased sea spray. Water rescue attempts may be hampered by reduced visibilities from the sea spray. Remember, NEVER turn your back on the ocean.

MTR WATCHES/WARNINGS/ADVISORIES
CA...Beach Hazards Statement through Monday morning for CAZ006-505- 509-530.

Wind Advisory from 11 PM this evening to 11 AM PDT Monday for CAZ504-512-514-515.

Coastal Flood Advisory until 3 AM PDT Tuesday for CAZ506.

PZ...Gale Warning until 3 AM PDT Monday for Pigeon Pt to Pt Pinos 0- 10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0- 10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.

Gale Warning until 9 PM PDT this evening for Mry Bay.

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