Marine Weather and Tide Forecast for Marin City, CA

SHORT TERM
(Today and tonight)
Issued at 1202 AM PDT Tue Apr 29 2025

The marine layer is reorganizing with a robust stratus deck offshore. The inland extent is limited mostly to the coast as high pressure keeps the layer of cool-moist air relatively shallow. A SW-NE oriented ridge will dominate the pattern today, allowing fair weather. Max temperatures will reach the mid to upper 70s for inland areas, with low 60s along the coast. A plume of upper level moisture will move in this evening, which will likely bring some high clouds and could make for a fantastic sunset.

LONG TERM
(Wednesday through Monday)
Issued at 1202 AM PDT Tue Apr 29 2025

The ridge will begin to weaken Wednesday as a short wave trough moves through. The models have been consistent with the existence of this feature, however the timing has shifted from Thursday to Wednesday over the last 24 hours. It now looks like the ridge will start to reorganize on Thursday before a more robust long wave trough approaches on Friday. This trough will likely spawn a cut-off low on Saturday that will move into Southern California by Sunday. This shifting pattern will bring fairly consistent warm and dry weather through the work-week with cooler, wetter conditions expected this weekend. The trough will support a surface cold front that will move through late Friday or very early Saturday. High PWAT anomalies ahead of the front will likely support some light, beneficial rain Friday night through Saturday morning, with some lingering post-frontal showers possible Saturday afternoon. While the rain could be widespread in areal coverage, the front should be moving pretty fast and there's only a 25% chance of exceeding 0.1" outside of the coastal mountains. Temperatures will also drop well below normal as overcast skies and a colder air mass move in. Perhaps the most impactful hazard is strong NW winds. The NBM ensemble mean, which typically has a low bias for these type of events, is showing 30-35 mph wind gusts on Friday, 35-45 mph on Saturday, and 30-40 mph on Sunday. The ECMWF ensemble is still the most aggressive model, with high confidence that SFO will see gusts above 40 mph on Saturday, although Friday and Sunday don't look nearly as bad in this ensemble. The confidence will increase over the next few days as higher resolution models start to resolve the event. As it stands, there is a decent chance for a wind advisory.

AVIATION
(12Z TAFS)
Issued at 413 AM PDT Tue Apr 29 2025

Currently a mixed bag of LIFR-VFR across the board. High pressure is allowing for a compressed, shallow marine layer and thus relatively lower ceilings and visibilities at coastal terminals.
VFR is expected by this afternoon with diurnal winds prevailing through the TAF period. A shortwave trough moving through tonight will deepen the marine layer, the uncertainty lies in the timing and if it can do so early enough in the night to result in higher ceilings and visibilities than are being observed now.

Vicinity of SFO...Currently VFR with westerly flow. An optimistic forecast through the morning as OAK has already had an MVFR ceiling with the time period of greatest concern between now and 16Z. After that VFR and westerly winds will prevail.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently LIFR with westerly flow at MRY and IFR with northerly flow at SNS. VFR is expected by this afternoon with a return to MVFR conditions tonight.

MARINE
(Today through Sunday)
Issued at 413 AM PDT Tue Apr 29 2025

Strong northwesterly breezes with near-gale force gusts will continue over the outer waters through Wednesday along with rough seas. Moderate seas and moderate northwesterly breezes will prevail Thursday and Friday. Strong northwesterly breezes and rough seas return Saturday to the outer waters.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 9 AM PDT Wednesday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.

Small Craft Advisory until 3 PM PDT Wednesday for Pigeon Pt to Pt Pinos 10-60 NM.