Issued at 829 PM PST Sat Jan 17 2026
High clouds make it difficult to see what's going on at the surface; however, webcams and ASOS sites show fog developing in the North Bay valleys as well as it seeping into Concord from the Delta. Will need to monitor the expansion of the fog, since currently only Concord is reporting quarter mile visibility. Should this continue to look likely and visibilities tank to the north, Dense Fog Advisories may be needed. For now, opting to hold off on issuing one just yet. For those traveling tonight or tomorrow morning, remember if you encounter fog while driving, slow down, use low beam headlights, and leave extra space between you and the car in front of you.
, Issued at 1240 PM PST Sat Jan 17 2026 (This evening through Sunday)
Not much change this afternoon, similar to yesterday with fog lingering in the interior East Bay Valleys and the West Delta. The most notable difference, is that we have high clouds moving from south to north across the region. We will continue to watch closely how these high clouds will affect afternoon temperatures, but largely should still be another warm day across much of the region this afternoon with high temperatures in the mid 60s to mid 70s (up to 80 degrees F in the higher terrain).
Tonight, look for fog (dense at times) to develop across the West Delta, North Bay Valleys, and interior East Bay Valleys that will linger into Sunday morning. Again, high clouds may limit overnight cooling by a few degrees making the fog forecast difficult. Offshore winds are forecast to decrease over the next 36 hours or so, and may allow for more cooling in the higher elevation tonight.
Looking for a near repeat for Sunday afternoon as high clouds will continue to stream across the region. Thus, temperatures will be similar to Saturday afternoon.
..issued at 1240 PM PST Sat Jan 17 2026 (Sunday night through next Friday)
Little change in the long term forecast as a mid/upper level ridge of high pressure will remain in place just off of the West Coast through midweek. Thus, look for similar conditions as this weekend to persist. Late night and early morning fog across the West Delta, North Bay Valleys, and interior East Bay Valleys looks like a good possibility.
By late week, there is a potential weak short wave trough forecast to impact the region with chances for light rainfall Friday into Saturday. However, it is looking the region may just see an increase in cloud cover and return of cooler conditions (closer to seasonal averages). It isn't until late January we see the Climate Prediction Center show the region leaning above normal in their 8-14 Day Precipitation Outlook.
(06z TAFS) Issued at 945 PM PST Sat Jan 17 2026
Pesky high clouds are covering up any signs of fog in our region, leaving us at the mercy of observations and webcams. What we do know, is that tule fog has developed in the Valley once again and has snaked into the Delta. Looking at webcams and ASOS/AWOS sites, dense fog generally remains confined to this area and KCCR as of this posting. Guidance does continue to favor socking in the the North Bay later tonight, with KSTS and KAPC bopping around MVFR to LIFR conditions. High clouds may play a factor in when and for how long IFR to LIFR conditions hold, particularly for KAPC and any East Bay terminals. Fog that develops should erode by mid to late morning, with VFR conditions returning for the afternoon and much of the evening.
Vicinity of SFO, Quiet and VFR conditions, plus light offshore winds continue for much of the TAF cycle. Winds may go variable for a bit overnight but return to offshore to northerly by tomorrow morning.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR conditions continue through the period. KSNS should hold with offshore flow through this period, while KMRY observes variable to light offshore during the overnight hours. Onshore flow returns to KMRY by late morning or early afternoon.
(tonight through next Friday) Issued at 829 PM PST Sat Jan 17 2026
Gentle to moderate northeast to east breezes persist across the San Pablo Bay, the Delta, and through the Golden Gate through early next week while light to gentle northeast to north winds continue across the rest of the coastal waters. Low seas continue today, with a northwest swell building to 5 to 6 feet by early to mid week. This will lead to low to moderate seas.
Ca, None. PZ, None.
