textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1211 PM PST Thu Dec 25 2025

- Severe thunderstorms are possible through the afternoon and evening. Damaging wind gusts are the main threats, with tornadoes possible.

- Strong southerly winds continue through Friday.

- A flood watch remains in effect through Friday evening across the region. The main threat is flash flooding and landslides from high rain rates.

- Dangerous beach and marine conditions continue through Friday across the Pacific coast and adjacent beaches.

- Cold temperatures settle in this weekend after the storms break

SHORT TERM

Issued at 1211 PM PST Thu Dec 25 2025 (This evening through Friday)

The active weather continues through this evening. While the widespread damaging winds have generally eased to a strong breeze, there are still reports of gusts near 50 mph across the Bay Area. The main threat today is possible severe thunderstorms. There has been some scattered storms through the morning, particularly in the North Bay with small hail and an unconfirmed funnel cloud reported. The first organized band of showers and possible thunderstorms is reaching San Francisco now. This will gradually slide south through the afternoon. The big event today will push through this evening, around 4-7 PM. A short wave with a robust low level jet will help trigger what looks like a very organized, fast moving N-S oriented line of thunderstorms. The early thunderstorms were somewhat unexpected and we decided to launch a special 18Z balloon to get better ground truth on how unstable the atmosphere actually is. The result was somewhat mixed. The overall CAPE was 170 J/kg, lower than some CAMs analyzed. But the distribution of was favorable, with most of the instability above the freezing level, but below 3 km. Overall the parameters were good for both high shear low CAPE tornados, and QLCS severe wind gusts. There is actually a very good signal on radar for a possible waterspout over the Monterey Bay at the moment, increasing confidence that the atmosphere can support tornadic activity today.

LONG TERM

Issued at 1211 PM PST Thu Dec 25 2025 (Friday night through next Wednesday)

Starting Friday, winds and shower activity will gradually decrease as the low pressure system offshore opens up into a trough and moves into northern Oregon. The associated surface trough axis will move across the Bay Area Friday evening. This will finally flip the winds back to northerly, bringing drier, cooler weather for the weekend. The 1000-500 mb thickness actually increases this weekend, with the cooling coming mainly from enhanced radiation during in the cloudless nights. Sunday through Tuesday look particularly calm, clear and cool as a 500 mb ridge sets in. The next troughing pattern looks probable on the 1st or 2nd, just in time for King Tides. There's no strong signal for major impacts yet, but the CW3E ECCC AR Activity tool shows higher than normal chances for atmospheric rivers through the first half of January.

AVIATION

(00Z TAFS) Issued at 513 PM PST Thu Dec 25 2025

A strong cold front continues to move eastward across the coastal waters resulting in showers and widely scattered thunderstorms. Expect rapidly changing weather conditions across the Bay Area and the north Central Coast through mid to late evening at the latest with quickly moving downpours and additional thunderstorms which may approach severe criteria of wind gusts to 50 knots (58 mph) or greater; conditions favor low level wind shear (LLWS), will add LLWS to TAFs as needed. The cold front will continue to press eastward out of the area overnight with winds gradually easing behind the front. It's VFR except MVFR-IFR in passing downpours, conditions easing overnight after the front moves to the east of the forecast area. Cooler air mass arriving may still bring widely scattered to scattered showers tonight and Friday.

Vicinity of SFO...Strong southerly winds, downpours and thunderstorms are also possible through mid evening to possibly late evening. Conditions easing overnight behind the passage of the cold front. Generally VFR for the period except MVFR-IFR in downpours.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Strong southerly winds, downpours and thunderstorms are also possible through mid evening to possibly late evening. Conditions easing overnight behind the passage of the cold front. Generally VFR for the period except MVFR-IFR in downpours.

..HAZARDOUS MARINE CONDITIONS CONTINUE INTO EARLY FRIDAY

Southeast gales continue across the coastal waters and will persist into Friday morning. These dangerous winds are accompanied by a chance for thunderstorms and possible waterspouts through the evening hours. Very rough, choppy seas will accompany these gales and linger through the day Friday, reinforced by a moderate westerly swell. If your vessel is not able to handle these conditions return to port or seek protected waters as soon as possible.

BEACHES

Issued at 350 PM PST Thu Dec 25 2025

A Beach Hazards Statement continues for the coast through 4 AM Friday. The main concerns include:blowing and drifting sand and wind waves up to 20 ft. The drifting sand and increased sea spray will also result in poor visibilities, affecting water rescues. Increased coastal erosion will be possible as well.

A High Surf Advisory is then valid for the coast from 4 AM to 10 PM Friday. For the High Surf Advisory: expect large breaking waves up to 25 feet, strong rip currents and sneaker waves. Dangerous swimming and surfing conditions and localized beach erosion can be expected. Sneaker waves can sweep across the shoreline without warning, pulling people into the sea from rocks, jetties and beaches. Large breaking waves can overpower swimmers resulting in significant physical injury and increase the risk of drowning.

Inexperienced swimmers should remain out of the water due to dangerous surf conditions.

Stay off of jetties, piers, rocks, and other waterside infrastructure. Remain out of the water to avoid hazardous surf and NEVER turn your back on the ocean. Monitor local weather, surf and tide forecasts at www.weather.gov/mtr.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement through late tonight for CAZ006-505-509- 529-530.

Flood Watch through Friday evening for CAZ006-502>506-508>510- 512>518-528>530.

High Surf Advisory from 4 AM to 10 PM PST Friday for CAZ006-505- 509-529-530.

PZ...Gale Warning until 3 AM PST Friday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm-SF Bay N of Bay Bridge.