, Issued at 1259 PM PST Fri Dec 5 2025 (This evening through Saturday)
Owing to the slower than expected stratus mix out and warming in the valleys of the North Bay and interior East Bay, have opted to decrease today's highs and tonight's lows in both areas, with the high temperatures now expected to rest in the middle to upper 50s and lows in the upper 30s to lower 40s in the area, with areas in the eastern tier of Contra Costa County going up to the lower 50s today.
For all other regions, the previous discussion is still valid: Satellite imagery reveals lingering impacts from the Tule Fog spillover across the valleys of the North Bay and the interior East Bay. The mix out process continues to be rather slow with marginal shrinkage of the stratus deck in the late morning, with the bulk of the mixing out expected to occur this afternoon into the evening. There is also a potential for drizzle to develop in the coastal waters tonight, fringe effects of a storm system that is bringing rain to the Pacific Northwest but is not expected to bring any precipitation on the land side of the Bay Area and Central Coast. This, in turn, could support the return of coastal stratus to the region. Otherwise, the weather remains generally clear through the day, as upper level ridging dominates the western United States. High temperatures today and Saturday range from the lower to middle 60s across the inland valleys, with the southern Salinas Valley reaching the upper 60s to near 70, and the upper 50s and the lower 60s near the coast. Lows will generally range from the lower to middle 40s inland and the middle to upper 40s along the coast. Some locations in southern Monterey County will drop into the middle 30s. Will need to monitor the need for a Cold Weather Advisory if the temperatures drop due to enhanced radiational cooling, or if temperatures in the North and East Bays stay cool due to lingering stratus impacts reducing the daytime heating effects.
..issued at 1215 PM PST Fri Dec 5 2025 (Saturday night through next Thursday)
Ridging will dominate the weather patterns through the rest of the 7- day outlook, enabling a gradual warming trend across the region. Rather than a day when the temperatures shoot upwards, we will experience a extended crescendo where the highs shoot up by a degree or two each day until you notice that by the middle of next week, temperatures are running 5 to 10 degrees above seasonal averages and highs in the inland valleys have reached the upper 60s to middle 70s. By the end of the 7-day forecast period, there are hints that a burst of offshore flow could come to the region, although exactly how strong that flow will be is open to lots of refinement.
Longer range model guidance suggests a possible change in the weather pattern towards the middle of the month. Ensemble model cluster analysis depicts the majority of model runs showing a continuing ridge, but substantial minorities (somewhere around 30- 40% of the ensemble members) depict a breakdown of the ridge. CPC guidance continues to show a slight lean, emphasize, a slight lean, towards precipitation totals above seasonal averages for December 13- 19 across the Bay Area. For context, within the long-term climatic averages, downtown San Francisco receives a little over an inch of rain during this period.
(00z TAFS) Issued at 406 PM PST Fri Dec 5 2025
VFR for most sites but localized fog is expected to impact STS, APC, and LVK tonight. Guidance shows some potential for low clouds/fog to impact coastal airports and SJC but confidence is too low to include in the TAF at this time. Bumped up arrival time of low clouds to LVK due to fog coverage not dissipating as much as models forecasted this afternoon. This may need to be further refined with arrival time of low clouds/fog brought even earlier. Winds generally stay onshore this afternoon and evening before weakening overnight. Moderate onshore winds return again during the day tomorrow.
Vicinity of SFO, VFR through the TAF period. Not currently anticipating fog/stratus to reach SFO tonight but visibilities may drop temporarily to around 6SM overnight. Continued the development of a moderate sea breeze this evening at SFO but confidence is low to moderate given winds have not switched NW yet. Winds weaken overnight before switching lightly north to northeasterly. Another moderate sea breeze returns tomorrow afternoon/evening.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR. Winds remain lightly onshore this afternoon/evening before weakening and becoming variable at times overnight before shifting onshore again during the daytime. There is some potential for low clouds to reach MRY tonight but confidence is slightly higher that low clouds will stay just offshore over the
(tonight through next Thursday) Issued at 406 PM PST Fri Dec 5 2025
Northerly continue to increase across the waters with fresh to strong gusts expected. Localized near gale force gusts are possible across the outer waters and in the favored coastal jet regions through the weekend. These winds persist into the upcoming work week. Moderate seas continue with seas building to between 6 to 8 feet Friday through Sunday.
Ca, Coastal Flood Advisory until 3 PM PST Sunday for CAZ006-506-508- 529-530.
PZ, Small Craft Advisory until 3 AM PST Saturday for Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 9 AM Saturday to 3 AM PST Sunday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PST Saturday for Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 3 AM PST Sunday for Pigeon Pt to Pt Pinos 10-60 NM.
