textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 125 AM PST Tue Jan 13 2026

- Chilly conditions this morning give way to warm daytime temperatures through the week with light offshore winds

- Elevated risk of sneaker waves through Thursday

- Pattern change possible next week

SHORT TERM

Issued at 125 AM PST Tue Jan 13 2026 (Today and tonight)

Fog has developed tonight in parts of Sonoma County, namely the Russian River Valley and the northern Santa Rosa Plain. It's a little hard to pick out in the satellite imagery, but it is being shown on local webcams and the observations from Sonoma County Airport. Visibilities should improve after sunrise this morning. Otherwise, skies remain clear across the Bay Area and Central Coast with light winds enhancing the chances for radiational cooling across the region. A Cold Weather Advisory is in effect across the interior North Bay and East Bay valleys and the interior Central Coast including the southern Salinas Valley through 9 AM as the lows dip into the lower to middle 30s across the area. Elsewhere, low temperatures reach the upper 30s to middle 40s in the lower elevations and upper 40s to lower 50s in the higher elevations.

No significant weather concerns today as an upper level ridge continues to dominate the weather pattern across the western United States. Light offshore flow is expected to develop with wind gusts topping out around the 15 to 20 mph range, and even then only during the morning across favored regions near the Golden Gate and the Pajaro Valley. High temperatures range from the upper 50s to lower 60s in the San Francisco area and the East Bay, and the middle 60s to the lower 70s in the inland valleys.

LONG TERM

Issued at 125 AM PST Tue Jan 13 2026 (Wednesday through Monday)

For the weekly forecast, it's wash, rinse, repeat. High pressure stalls over the western United States, resulting in an extended period of seasonally warm daytime highs, mild nighttime lows, and light offshore winds. To give an idea of the regional warmth, high temperatures through the upcoming weekend are around 5 degrees above the seasonal average in downtown San Francisco, and around 8 to 15 degrees above the seasonal average across the rest of the Bay Area and Central Coast.

Towards the early part of next week, just beyond the end of the 7- day outlook, the upper level ridge begins to erode, allowing temperatures to cool. Beyond that, the level of uncertainty over the evolution of the weather pattern shoots upward. The previous forecaster noted the split between those models that break down the upper ridge more quickly into onshore flow and those that kept the ridging in place a little longer. Looking at the latest ensemble model cluster guidance, this still appears to be the case. By the 21st, the ensemble model clusters are split roughly half-to-half between those with a more pronounced trough across the West Coast and those that keep more zonal flow or even a residual ridge in place. All together, it appears that a period of more active weather may be in store as we head towards the end of the month.

AVIATION

(06Z TAFS) Issued at 920 PM PST Mon Jan 12 2026

VFR conditions expected at most terminals tonight and through the day Tuesday. The exception is STS. Cameras are showing fog starting to fill the Russian River Valley downstream of the terminal. This is typically an early indicator that localized dense fog will reach the terminal in a few hours. Otherwise there is only a slight chance for fog at the other terminals Tuesday morning, with clear skies and mostly gentle winds through the day.

Vicinity of SFO...The probability for IFR visibility Tuesday morning has decreased below 10% as weak offshore wind continues to mix in some dry air. If any fog does manage to form over the Bay, it should be short lived. While the wind direction will remain offshore, the speed will continue to be light enough to avoid impacting any preferred runway schemes.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...High confidence in VFR conditions through the TAF period. SNS will have moderate ESE winds in the mid to late morning as the offshore gradient combines with the typical drainage flow.

MARINE

(Tonight through next Sunday) Issued at 920 PM PST Mon Jan 12 2026

High pressure is bringing mostly favorable conditions through the week. Winds will be gentle to moderate from the North. The moderate- rough westerly swell will gradually subside, although a few rounds of low, long period swell will impact the coastal waters through Friday.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Cold Weather Advisory until 9 AM PST this morning for CAZ506-510- 516-518.

PZ...None.