Issued at 658 PM PDT Fri May 22 2026
Coastal stratus is beginning to flow into the inland regions this evening, particularly through the Petaluma Gap, Golden Gate, and across the Monterey Bay region. The latest readings from the Bodega Bay profiler suggest that the marine layer has further thickened to around 2000 feet. If this holds overnight, the higher elevations and perhaps the very eastern sections of Contra Costa County will be the only regions to escape stratus cover tonight.
DialH
, Issued at 1250 PM PDT Fri May 22 2026 (This evening through Saturday)
The marine layer deepen to ~1500 ft this morning and resulted in cooler conditions along the coast and adjacent valleys. May not have lowered temperature in these areas enough, however they are on a warming trend now the Sun is out. Thus, expecting afternoon temperatures to warm into the upper 70s to middle 80s across the interior, lower 60s to lower 70s around the San Francisco bayshore, and upper 50s to middle 60s near the coast. Dry conditions persist this afternoon with elevations above 1500 ft are seeing 10%-30% humidity values.
As the marine layer is forecast to remain steady, low clouds near the coast will spread further inland this evening and spread deeper into the valleys early Saturday morning. There is also the potential for coastal drizzle, yet the probability is not great enough to include in the official forecast grids.
For Saturday afternoon, we are expecting slightly cooler temperatures than today as stratus will be slower to clear. This is also in response to more zonal for developing over the region.
..issued at 1250 PM PDT Fri May 22 2026 (Saturday night through next Thursday)
Zonal flow will persist on Sunday, thus temperatures will be similar to those on Saturday as far as afternoon maximum temperatures go. During the late evening and overnight hours, cannot rule out coastal drizzle again Saturday night into Sunday morning.
By late Monday and early Tuesday, a cold front associated with a deep upper level through is forecast to sweep across the region. This would result in drizzle and/or light rain as the front moves from north to south across the Bay Area and Central Coast. However, widespread rainfall is not expected and will be very light not amounting to much more than a few hundredths of an inch. In wake of the frontal passage, the marine layer may mix out and allow for coastal locations slightly warmer compared to this weekend. Winds are also forecast to strengthen over the coastal waters on Tuesday and Wednesday.
From the previous forecaster: "Towards the later part of the week, the ensemble model runs begin to diverge as the evolution of the upper level low and incoming ridging becomes uncertain. Most runs lean towards a warming trend for that period, which is reflected in the current forecast, with a significant minority (around 30-40% of the runs) suggesting that some form of trough lingers through the period."
(00z TAFS) Issued at 533 PM PDT Fri May 22 2026
A prominent coastal stratus deck is expected to impact most terminals Friday night into the overnight hours as the marine layer deepens to ~1800 feet by early Saturday morning. The stratus push onshore will bring IFR-LIFR ceilings to all terminals except for the interior South and East bay valleys. Visibility impacts will be limited to the coastal and North Bay sites coinciding with the lower ceilings. Conditions are expected to improve to VFR by Saturday afternoon with coastal sites experiencing some lingering low-level stratus. Gentle to moderate breezes will prevail through the TAF period.
Vicinity of SFO, Moderate winds prevail through the evening before easing up late Friday night. As the winds become light, the stratus deck will begin to creep in with borderline MVFR-IFR ceilings. The stratus deck is expected to remain until it scatters out by late morning Saturday when winds increase to moderate strength. Conditions will remain VFR through the end of TAF period, though there may be another return of low ceilings Saturday night.
SFO Bridge Approach, The marine layer will not be as prominent or deep. Therefore, any developing low cloud deck will likely remain few to scattered before dissipating by late Saturday morning. Winds follow the same general pattern as SFO, though remain more NW to W.
Monterey Bay Terminals, The marine layer is beginning to funnel into Salinas Valley as of 5:30pm PDT Friday. The marine stratus will continue to push inland bringing IFR ceilings and misty conditions to the terminals by Friday evening. By late Friday night, IFR ceilings will develop as local light breezes develop. Stratus should begin to mix out of the terminals, resulting in VFR conditions, by late Saturday morning as onshore winds increase.
(today through Wednesday) Issued at 838 AM PDT Fri May 22 2026
Light to moderate winds will shift across the waters through the day, becoming southwesterly and light. The sea state will improve heading into the holiday weekend as northwesterly swell continues to decrease.
Ca, None. PZ, Small Craft Advisory until 9 AM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM.
