, Issued at 1215 PM PDT Thu Sep 10 2026 (This evening through Friday night)
After a warm start to the day, the interior will remain very warm to hot with the ongoing Heat Advisory still in place until 10 PM PDT this evening. However, we are already seeing cooler conditions near the coast as a shallow marine layer is forecast to return as well as an increase in onshore winds.
Tonight, temperatures are forecast to cool into the mid 50s to near 60 deg F near the coast and across the interior valleys. However, the higher elevations look to only cool into the 70s and potentially the lower 80s. Coastal stratus and/or fog look to develop along the coast and potentially into the North Bay Valleys overnight as the marine layer deepens to around 500 feet.
On Friday, depending on how much stratus/fog develops in the morning, the cooling trend will continue with temperates moderating to near seasonal averages with mostly sunny conditions across the interior. This is a result of the mid/upper level through deepening off of the Pacific Northwest coast and high pressure over the Desert Southwest being suppressed to the south.
..issued at 1215 PM PDT Thu Sep 10 2026 (Saturday through next Wednesday)
The gradual cooling trend will continue into the weekend as the low pressure off of the Pacific Northwest coast deepens further, bringing rainfall to that region. This will allow the marine layer to deepen as well, reaching around 1500 feet by Saturday night into Sunday. This would also bring increased afternoon and evening winds in the favored valleys, peaks, passes, and gaps.
Beyond this weekend, troughing off of the West Coast looks likely to persist. This will allow for afternoon maximum temperatures to be near to slightly below average and overnight minimum temperatures to be near or slightly above.
(18z TAFS) Issued at 1037 AM PDT Thu Sep 10 2026
Currently VFR with high clouds. Moderate confidence on ceilings on the cusp of IFR/MVFR returning to bayshore and coastal terminals tonight. Satellite shows a surprisingly decent push of stratus just beginning to enter our coastal waters from the north. Reasonable worst case scenario is a more compressed marine layer will bring lower ceilings and visibilities (likely LIFR); however, that would likely remain confined to the immediate coast. Diurnal winds will prevail.
Vicinity of SFO, Currently VFR with northwesterly flow. Moderate confidence on a ceiling on the cusp of IFR/MVFR developing tonight. Diurnal winds will prevail.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Currently VFR with northwesterly flow at both terminals. Moderate confidence on IFR ceilings returning tonight. Diurnal winds will prevail.
(today through Tuesday) Issued at 913 AM PDT Thu Sep 10 2026
Moderate to fresh northwesterly breezes will prevail through Friday, increasing to become fresh to strong this weekend into next week. Locally hazardous conditions for small craft today will expand to become widespread this weekend into next week. Moderate seas will prevail through the weekend, building to become rough in the outer waters Monday.
Ca, Heat Advisory until 10 PM PDT this evening for CAZ006-502>506- 508>510-512>518-528>530.
PZ, Small Craft Advisory from 3 AM to 9 PM PDT Friday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory from 9 AM to 9 PM PDT Friday for Pigeon Pt to Pt Pinos 0-10 nm.
Small Craft Advisory until 9 PM PDT Friday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
