textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 150 AM PST Sat Feb 21 2026

- Cold to very cold conditions this morning

- Unsettled weather with periods of rain and wind through the long term forecast period

SHORT TERM

Issued at 150 AM PST Sat Feb 21 2026 (Today and tonight)

Surface high pressure across the Intermountain West will dominate our weather today. Clear skies and light winds are allowing for efficient radiational cooling on top of an already cold air mass. The 00z sounding observed an 850 millibar temperature of -1.35 degrees Celsius which is below the tenth percentile (-0.5 degrees Celsius) for the date and time. Sensible weather wise this means it will be another cold to very cold start to the day with temperatures topping out below normal this afternoon. The combination of the aforementioned high pressure and a developing storm force low pressure system off the Pacific Northwest Coast will tighten the pressure gradient and yield strong southerly winds. Gusts up to 40 mph are expected along the Pacific Coast and in the higher terrain. The proximity to the aforementioned low will allow for pre-frontal rain showers beginning this afternoon, primarily for the North Bay. Rates will be light with no adverse impacts expected. South of the Golden Gate Bridge can expect an increase in cloud cover and maybe some drizzle. Sunday will be very similar with the most notable difference being temperatures rebounding to near normal.

LONG TERM

Issued at 150 AM PST Sat Feb 21 2026 (Sunday through Friday)

ECMWF and GEFS ensembles are in agreement of heights rising through the first half of Monday with upper-level ridging across the Intermountain West and upper-level troughing off the Pacific Northwest Coast. The ridge will get tamped down on Tuesday; however, there is great agreement that the region will remain under the influence of the ridge and its positive height anomalies. A surface low pressure system off the Pacific Northwest Coast will pull moisture in from the tropics Monday into Tuesday. ECMWF and GEFS IVT ensemble mean peaks near 500 kg/ms and weakens the system as it sinks south. Southwesterly flow (from the tropics) will allow for efficient rainfall due to the fetch of moist, warm air. As a result, southwest facing terrain will have the highest accumulation with the help of orographic lift with the lee side valleys experiencing the rain shadow effect. Confidence is high that the North Bay will see the highest rainfall totals. The trend continues to be our friend as it shifts northward, subsequently lowering rainfall totals and delaying the onset as it does so. As the forecast looks right now, the Monday night into Tuesday system will bring widespread rainfall. Minor flooding of low-lying, poor drainage, and urban areas will be possible with ponding and slick roadways likely. Mainstem river flooding is not expected with a low probability (less than 5%) of occurrence. If rain rates do end up being high enough with this system, shallow landslides will be possible. A warming and drying trend kicks off Wednesday after the cold frontal passage with temperatures climbing to 10 degrees above normal by Friday.

AVIATION

(12Z TAFS) Issued at 309 AM PST Sat Feb 21 2026

VFR conditions prevail through the TAF period with mid- to high level clouds expected throughout the region. There is a low confidence for MVFR conditions and isolated showers in the North Bay valleys and the immediate coastal region, which is too low confidence to include in the TAFs at this time. Better chances for MVFR ceilings and showers come to the North Bay and the immediate coast tonight into Sunday morning, just before and after the end of the TAF period. Surface winds will remain light through the morning before increasing from the south through the afternoon, with gusts reaching 20-25 knots in favored areas. Tonight into Sunday morning, some LLWS is possible, with the greatest impacts across the interior regions.

Vicinity of SFO... VFR with mid- to high level clouds through the TAF period. Southerly flow will increase through the afternoon with gusts to 25 kt into the evening hours. There are some high resolution models bringing scattered showers to the terminal area Sunday morning, but the southwesterly approach should shield SFO itself from any rain. Local topography makes showers more likely at OAK.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR with some mid- to high level clouds across the region and through the TAF period. Breezy southeast winds increase this afternoon with speeds of 15-20 kt, diminishing at MRY in the evening while breezy drainage flow continues at SNS.

MARINE

(Today through Thursday) Issued at 309 AM PST Sat Feb 21 2026

Expect fresh to moderate southerly breezes this morning with gale force gusts developing by the afternoon, especially across the northern waters. Rough to very rough seas persist starting tonight into the beginning of next week. Rain chances increase across northern waters tonight, becoming more widespread across the northern waters by Saturday night, then spread farther south by Sunday and Monday. Winds and seas begin to ease by the middle of next week.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Cold Weather Advisory until 9 AM PST this morning for CAZ504-506- 510-513-515-528.

Extreme Cold Warning until 9 AM PST this morning for CAZ514- 516>518.

PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PST Sunday for SF Bay N of Bay Bridge.

Small Craft Advisory from 3 PM this afternoon to 9 PM PST this evening for Mry Bay.

Small Craft Advisory until 3 PM PST this afternoon for Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

Gale Warning from 3 PM this afternoon to 3 AM PST Sunday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm- Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory from 9 AM this morning to 3 PM PST this afternoon for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

Gale Warning from 3 PM this afternoon to 9 PM PST this evening for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.

Gale Warning until 3 AM PST Sunday for Pt Arena to Pt Reyes 10- 60 NM.