Issued at 921 PM PST Wed Dec 17 2025
Radiative stratus and fog is developing across the inland valleys and the Monterey Bay region tonight, expected to continue to expand across the Bay Area as the night progresses. Dense Fog Advisories have been issued for the East Bay Interior Valleys, the Northern Monterey Bay region (namely, the coastal plain of Santa Cruz County), and the Monterey Bay itself through 7 AM Thursday. Will continue to monitor the development of stratus and fog overnight in case additional advisories are necessary. If you encounter dense fog while driving, slow down, use low beam headlights, and leave extra space between you and the car in front of you.
DialH
, Issued at 226 PM PST Wed Dec 17 2025 (This evening through Thursday)
A mix of Sun and clouds for the remainder of the afternoon in the wake of a relatively weak cold front that pushed through our area earlier this morning. Rainfall received overnight and this morning was beneficial with most low lying areas seeing around a tenth-of-an- inch, and higher elevations seeing from a tenth-of-an-inch to half- an-inch. Expect areas of dense fog to develop overnight within inland valleys. especially the North Bay, Bay Area and East Bay. Closer to the coast, fog and drizzle will combine to limit visibility overnight into early Thursday morning.
Thursday will be mostly dry with the exception of the coastal drizzle that should taper off an hour or two after sunrise. Thursdays high temperatures will be right around normal, slightly above normal for higher elevations within the Central Coast. The first wave of numerous rounds of rainfall will first move into the North Bay late in the day Thursday with only light rain for the onset into Friday.
..issued at 226 PM PST Wed Dec 17 2025 (Thursday night through next Tuesday)
Plenty of uncertainty remains with the exact timing and intensity of the rainfall we're expecting to impact our area beginning Friday through the remainder of the extended forecast. What we do know attm is the North Bay will see the most rainfall as several waves of moderate/heavy rainfall push through over the next week, along with elevated coastal ranges from San Mateo south through the Santa Cruz mountains into the Santa Lucia's. The period of heaviest rainfall as of this writing looks to be late Saturday night through early Monday morning, which means Sunday may be difficult travel day. Give yourself plenty of extra time to travel at anytime over the next week, but especially Sunday.
The totals over the coastal ranges will standout on ours and others weather maps you'll see as we head into one of the busiest travel times of the year. However, low lying areas all across our region will see plenty of impacts from the rain, wind and other cumulative problems associated with multiple storm systems moving over our area. By the beginning of next week we are likely to see rivers begin to swell and the potential for rock and land slides to interfere with travel plans. Signals for rainfall chances beyond the scope of our official forecast persist into the end of next week as well.
Most of the Pacific Coast is highlighted in CPC outlooks for excessive rainfall through the extended forecast. Please monitor our web page (weather.gov/mtr) for updated rainfall total maps, more specific timing and impacts for our area along with our partners at the CPC for bigger picture products across the West Coast (cpc.ncep.noaa.gov).
(06z TAFS) Issued at 921 PM PST Wed Dec 17 2025
Generally radiative stratus and fog is developing across the interior valleys and Monterey Bay region, with a patchwork of MVFR- LIFR conditions across the impacted region. General expectation is for the stratus deck to expand through the night with conditions gradually improving through Thursday morning. Around that time, a band of MVFR clouds will come into the North Bay associated with an incoming frontal system, with STS not clearing out to VFR and APC's clearing a moderate confidence forecast. The rest of the region should get VFR conditions with light onshore flow Thursday afternoon with stratus returning late in the evening hours. Rain chances begin Thursday evening, favoring the North Bay and windward slopes across the Bay Area, expanding in coverage after the end of the 24-hour TAF period.
Vicinity of SFO, VFR conditions continue through the next several hours with light winds. Moderate confidence that MVFR stratus returns to the terminal around midnight with a gradual diminishing to IFR conditions through the pre-dawn hours. The latest high resolution model output depicts the stratus developing mainly over the SF Bay and the eastern shore, but retains enough of a signal for impacts to the terminal to keep the previous forecast in place. Clearing is expected late Thursday morning, with a return to breezy west-northwest winds in the afternoon. Stratus returns late Thursday evening in advance of a rain band expected to arrive close to the end of the TAF period.
SFO Bridge Approach, Somewhat higher confidence in direct stratus impacts to the approach path tonight. Otherwise similar to SFO.
Monterey Bay Terminals, LIFR stratus through the night with shallow fog possible at the terminals. VFR conditions return late Thursday morning with the return of breezy northeast winds. MVFR stratus returns to MRY near the end of the TAF period, and to SNS shortly afterwards, as the frontal band approaches the region.
(tonight through next Tuesday) Issued at 921 PM PST Wed Dec 17 2025
Dense fog continues across parts of Monterey Bay and is expected to persist through the early morning hours. Low visibilities will create hazardous conditions for mariners, who should proceed with caution, use proper fog signals, and make sure all running lights are on. Light to moderate onshore breezes prevail with moderate seas through late week. Rain chances return to the northern waters on Thursday night and push southward through the day on Friday. Additional rain arrives Saturday night and continues off and on at times through much of next week.
Ca, Dense Fog Advisory until 7 AM PST Thursday for CAZ510-529.
PZ, Dense Fog Advisory until 7 AM PST Thursday for Mry Bay.
