Issued at 855 AM PST Fri Jan 16 2026
Will allow the Dense Fog Advisory to expire at 9 AM PST for the North Bay Valleys as visibilities have improved over the past few hours and will continue to do so as the Sun rises and temperatures begin to warm. However, there is patchy to areas of dense fog across the East Bay Valleys and the West Delta, most notably the Concord and Byron areas as Tule Fog has spread westward. This area may not see visibilities improve until late morning or early afternoon, yet mostly sunny sky conditions are likely across all of the region this afternoon. Otherwise, no updates are needed at this time.
RGass
, Issued at 1241 AM PST Fri Jan 16 2026 (Today and tonight)
The 00Z sounding found a near record temperature at 850 mb (16.6 C vs 16.8 C, avg: 7.4 C). This is leading to pretty dramatic thermal belting, with warm air in the mountains and cold air settling in the valleys. Healdsburg is currently 39 F, while less than 5 miles away, the Healdsburg Hills are reporting 70 F at 1700 ft. The cold valley air is reaching saturation as the temperatures drops to the dew point. Patchy fog is being reported across the valleys. The coverage is spotty and highly dependent on the wind speed. Over the next several hours the coverage should continue to expand and become more resilient as the cloud layer deepens in the North Bay Valleys. The Salinas Valley is a little more tricky as mixing from increasing drainage flow down the valley will counter-act further radiational cooling. It's difficult to say which effect will win, but we expect the Salinas Valley fog to be thinner, more patchy, and clear sooner than the calmer North Bay Valleys. After the fog clears we are in for another beautiful day with clear skies and mild temperatures.
..issued at 1241 AM PST Fri Jan 16 2026 (Saturday through Thursday)
Nice, dry weather will continue for the next several days. Some high clouds will roll in from the south this weekend, which should moderate both max and min temperatures a bit, while producing some colorful sunrises and sunsets. Ensemble cluster analysis shows high confidence that the strong ridge at 500 mb over the Gulf of Alaska will gradually erode over the next 5-7 days. The uncertainty grows beyond the middle of next week, but either zonal flow or a troughing pattern seems more likely than continued ridging. While the change at the surface will be subtle, onshore flow will gradually return, high temperatures will cool a few degrees, and coastal clouds will start creeping back in by the middle of next week. If the pattern becomes more active, there is a chance for very light rain as early as next Thursday, with a stronger signal for more substantial precipitation by the middle of the following week (end of January).
(12z TAFS) Issued at 353 AM PST Fri Jan 16 2026
VFR continues for most TAF sites through the TAF period. The exceptions will be STS, APC, and HAF which will see fog this morning and again in tonight for APC and STS. Winds will mostly say light through the TAF period with directions being mostly variable, although some localized effects will determine the wind directions at a few of the TAF sites.
Vicinity of SFO, VFR through the TAF period. Expect mostly light and variable winds through much of the day before winds turn northerly in the late afternoon, but become variable again into the night.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR through the TAF period. East to southeast winds last through into the afternoon before winds turn northerly. Winds turn easterly and southeasterly again into the night.
(today through Wednesday) Issued at 855 AM PST Fri Jan 16 2026
Locally breezy winds expected across the San Pablo Bay, the delta, and through the Golden Gate Gap through this weekend. Elsewhere, light northeasterly to northerly winds persist through the forecast period. Light seas continue into early next week before our next round of long period swell arrives and brings light to moderate seas.
Ca, None. PZ, None.
