, 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.
(18z TAFS) Issued at 1020 AM PDT Sun Oct 18 2026
Currently IFR-VFR. The marine layer was observed around 500 feet this morning and is expected to deepen through the TAF period. Stratus is off the coast with a feed through the Golden Gate Gap. With the deepening of the marine layer, moderate confidence in MVFR conditions returning to all terminals tonight as it's able to penetrate farther inland. Onshore winds will prevail.
Vicinity of SFO, Currently VFR with northwesterly flow. Moderate confidence in an MVFR ceiling developing at the terminal tonight, likely early. The San Bruno Gap has been able to hold off stratus so far, but if the marine layer deepens to around 1,000 feet, there will be nothing stopping IFR/MVFR stratus from reaching the terminal earlier. Westerly/Northwesterly winds will prevail, becoming gusty in the afternoon and evening.
SFO Bridge Approach, The San Mateo Bridge Approach will likely have clouds at or below FL070 from 04Z to 17Z.
Monterey Bay Terminals, Currently VFR and calm at both terminals. Moderate confidence on MVFR conditions returning to the terminals tonight. Diurnal winds will prevail.
(today through Friday) Issued at 1020 AM PDT Sun Oct 18 2026
Moderate to fresh northwesterly breezes will prevail through Monday, bringing widespread hazardous conditions across the coastal waters Sunday afternoon. Winds will diminish and back to become southerly Tuesday and Wednesday before returning to moderate to fresh northerly breezes Thursday. Rough seas across the outer waters will subside to become moderate Monday, rebuilding to become rough Tuesday. Light rain showers are expected Tuesday through Thursday.
Issued at 1020 AM PDT Sun Oct 18 2026
Hazardous beach conditions will be present at Pacific Coast beaches Sunday. 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 until 9 PM PDT 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.
