, Issued at 143 AM PDT Sun Oct 18 2026 (Today and tonight)
Sunday and Monday mark the transition towards cooler conditions and breezy onshore winds. Weakening high pressure allows the marine layer to gradually reform and deepen, though it will be short-lived. Nonetheless, any marine layer presence aids to initiate the beginning of a cooling trend, even if it remains shallow and confined to the coast Sunday morning. As the upper-level trough digs southward along the West coast on Sunday, a strengthening onshore pressure gradient will support moderate westerly breezes. This set up can support wind gusts around 20-25 mph through the Petaluma Gap/Valley with the Altamont and Patterson Passes experiencing gusts closer to 25-30 mph.
Sunday maximum temperatures are forecast to reach the 60s to low 70s along the coast, mid 70s to mid 80s across the interior, with the usual hot spots reaching into the low 90s. On Monday, the maximum temperatures drop further due to increased cold air advection from the upper-level trough. Max temperatures are forecast to reach the mid 50s to mid 60s at the coast, mid 60s to low 70s across the interior, with the southernmost extent of the Central Coast remaining in the mid 70s to low 80s.
..issued at 143 AM PDT Sun Oct 18 2026 (Monday through Saturday)
Monday night has a better chance for a marine layer around 1500 ft as the center of the upper-level trough deepens along our coastline. By Tuesday morning however, the first round of light rain arrives with precipitation chances around 20-40% across the Bay Area and Central Coast. Rainfall can overpower the marine layer by saturating the atmosphere above it, thereby mixing out. Our stratus marine layer is typically capped by an inversion, defined as layer of the atmosphere where temperature increases with height. Introducing rain into the mix perturbs and cools the inversion layer causing it to disappear resulting in no marine layer. Though there will still be deep convective cumulus clouds present!
By Tuesday afternoon, the cut-off low pressure system slows down and stalls directly to our west with its center approximately 300-350 miles west of San Francisco. As it stalls, a plume of moisture originating in the Eastern Pacific gets funneled into the eastern portion of the system from the south. By Wednesday morning, the system begins to propagate eastward towards the Central Coast. Given the nature of cut-off lows combined with an increased moisture flux and terrain interactions, there is potential for precipitation to wrap around the system's center giving way for widespread light rain on Wednesday across the Bay Area and Central Coast (40-75% chance). European and GFS ensemble members continue to agree on precipitable water values above the 75th percentile on Wednesday. Rainfall chances gradually diminish by Thursday, but cooler conditions remain through the end of the week.
The potential for thunderstorm development (<15% chance) remains near the Central Coast. Compared to yesterday's model runs, the deterministic European model trended upwards in relation to most unstable CAPE which is estimated to be around 200-350 J/kg. There is sufficient instability and moisture available to support thunderstorm development. Though lift is a limiting factor as it is dependent on the alignment and trajectory of the system when it approaches the coast.
(12z TAFS) Issued at 522 AM PDT Sun Oct 18 2026
Satellite imagery this morning shows stratus from roughly Bodega Bay down to the Santa Cruz Coast and portions of the Monterey Bay. The marine layer looks to be around 500ft so far, which could lead to some patchy fog development around sunrise. Stratus and any fog that develops should quickly erode today, the exception being along the San Mateo coast near KHAF. The question will be, will they remain socked in with MVFR cigs, or scatter out? Elsewhere, VFR conditions are expected into the afternoon. Stratus attempts to make a return during the early evening hours, with low cloud penetrating a bit more inland overnight. THe marine layer is expected to get to around 1000ft, which should bring MVFR cigs.
Vicinity of SFO, Stratus should stay west and flirt around SFO this morning, leaving us with VFR conditions. Should clouds fill in the next couple of hours, they'll be short lived as they'll quickly retreat to the coast by late morning. Tonight, there's a better chance for stratus to reach the terminal. A few models show we could see some clouds starting to creep in by 3Z; however, most show it happening closer between 7-10Z. MVFR cigs are expected, with the potential IFR cigs around sunrise. Clouds should clear by mid to late Monday morning.
In addition to the clouds, gusty onshore winds are forecast this afternoon and into the evening with gusts peaking around 25kt.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Stratus is meandering around the Monterey Peninsula, and starting to blossom just outside of KSNS. Current thinking is we should see stratus and perhaps some patchy fog develop around sunrise, lasting for a few hours before clearing out. Onshore flow picks up for the afternoon, with winds weakening after sunset. Stratus should develop a bit earlier this evening, leading to night of MVFR to then IFR cigs.
(today through Friday) Issued at 522 AM PDT Sun Oct 18 2026
Winds will increase today with moderate to fresh northerly breezes prevailing through Monday with locally strong breezes across the northern outer waters. Widespread hazardous conditions will spread across the coastal waters as a result Sunday afternoon, likely continuing into Monday. Moderate seas will prevail across the inner waters with rough seas across the outer waters through Tuesday. Light rain showers are expected Monday night through Wednesday.
Issued at 1002 AM PDT Sat Oct 17 2026
Hazardous beach conditions will be present at Pacific Coast beaches through Sunday and likely into next week. Long period southerly/southwesterly swell will bring an increased risk for sneaker waves and strong rip currents with breaking waves of 7 to 12 feet. 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 with strong rip currents and never turn your back on the ocean!
Sarment
Ca, Beach Hazards Statement through this evening for CAZ006-505-509- 529-530.
PZ, Small Craft Advisory until 9 PM PDT this evening for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this evening for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
