Marine Weather and Tide Forecast for Belmont, 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
(00Z TAFS)
Issued at 443 PM PDT Sun Mar 8 2026

VFR conditions will continue to prevail through the evening. Winds have returned to an onshore direction for all terminals. This is bringing cooler, more humid air to the lower atmosphere. The two biggest questions with this set of TAFs are whether a shallow marine layer will become established, and if that marine layer will bring stratus or fog impacts to the coastal terminals. While the probability of visibility impacts is generally around 20%, any impacts should hold off until well after midnight.

Vicinity of SFO...Fairly typical onshore winds have returned to the terminal with mostly clear skies. The only potential impact is marine layer type stratus for a few hours Monday morning. The uncertainty is too high to include more than a hint of this possibility in the TAF, but if the coastal stratus bank becomes more organized tonight the chances of ceilings reaching the terminal will increase drastically.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...It's a different story at the Monterey Bay terminals. There is a much higher chance of both ceilings and visibility impacts Monday morning. The 22Z HRRR is suggesting a cyclonic eddy will form in the Monterey Bay as NW winds are shielded coming off the coast of Santa Cruz county. This feature is very effective at pumping low level moisture to both MRY and SNS.

MARINE
(Tonight through next Friday)
Issued at 443 PM 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 9 AM PDT Tuesday for Pt Arena to Pt Reyes 0-10 nm.

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

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

Gale Warning until 9 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 9 AM PDT Tuesday for Pigeon Pt to Pt Pinos 10-60 NM.