, Issued at 1228 PM PDT Thu Aug 13 2026 (This evening through Friday night)
A mid/upper level trough of low pressure remains off of the West Coast and is resulting in widespread cooler temperatures this afternoon, as much as 15 deg F below normal. Humidities across the region have also improved, especially beneath the approximately 2,200 foot marine layer. The potential for high-based convection has also greatly diminish as the higher PWAT values and insatiability continue to shift eastward as a result of the troughing of of the coast. Low clouds are highly likely to return to the coast this evening and spread into the interior valleys early Friday morning. Have also added patchy drizzle to favored locations as the marine layer is forecast to deepen to around 2,500 feet overnight. On Friday, expecting a slower stratus retreat to the coastline with similar or slightly cooler temperatures than today. Friday night into Saturday morning, expecting another around of widespread drizzle along the coast and in the favored upslope regions.
..issued at 1228 PM PDT Thu Aug 13 2026 (Saturday through next Wednesday)
A subtle warming trend is forecast to begin by Saturday afternoon, yet temperatures will remain below seasonal averages into much of next week. This is as the trough off of the West Coast weakens and the ridge begins to build over the Desert Southwest. As a result, the marine layer is forecast to compress with more typical late morning to early afternoon retreat of stratus to the coastline.
(06z TAFS) Issued at 959 PM PDT Thu Aug 13 2026
MVFR-IFR stratus is expanding across the region and will impact all terminals overnight. Lingering southwesterly breezes will gradually diminish through the next few hours. Stratus is not expected to dissipate until early Friday afternoon, around 19-21Z for most terminals. Low to moderate confidence that more northwesterly flow will develop Friday afternoon and evening, with moderate to high confidence that stratus will again develop across the region on Friday evening, with moderate confidence on the exact timing.
Vicinity of SFO, MVFR ceilings arrive imminently and persist into the early afternoon on Friday. Light to gentle southwest winds persist overnight into Friday morning. Low to moderate confidence that winds will turn more towards the west or west-northwest on Friday afternoon and evening, with moderate confidence in stratus returning to the terminal sometime Friday evening to Friday night, although confidence in timing is low to moderate.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, MVFR conditions persist through the overnight hours with some IFR ceilings possible at MRY. Light winds persist overnight before a moderate confidence forecast for more northwesterly flow develops Friday afternoon. Low confidence in a brief scattering out of the stratus clouds Friday afternoon a couple of hours in the afternoon before stratus returns early Friday evening.
(tonight through next Wednesday) Issued at 959 PM PDT Thu Aug 13 2026
Gentle to moderate west-northwest winds persist into the weekend and early next week as seas continue to subside to moderate in response. A long period southerly swell of about 16 to 18 seconds approaches the coast Friday night into Sunday. Winds will build to a fresh northwest breeze early next week, causing seas to build up to 9 feet. Light drizzle is possible across the coastal waters. Haze and smoke may also impact visibility along the Big Sur coastline due to the Timber fire.
Ca, None. PZ, None.
