textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 341 AM PST Sun Mar 1 2026

- A series of troughs will bring cooler weather and cloudier skies through Wednesday

- Strong winds expected along the coast and higher terrain Wednesday through Friday

- Offshore winds will bring warmer and drier weather into the weekend

UPDATE

Issued at 858 AM PST Mon Mar 2 2026

Light rain and/or drizzle is still being reported across much of the region this morning. However, the overnight into Monday morning's rainfall totals have generally been a trace up to 0.10". As the day progresses, the forecast trends drier as a weak shortwave ridge builds in wake of the exiting trough on Tuesday. As such, the forecast remains on track with no updates anticipated this morning.

RGass

SHORT TERM

Issued at 1252 AM PST Mon Mar 2 2026 (Today and tonight)

A cut-off surface low is situated just off the coast of Cape Mendocino. The associated upper level low and trough has overran the surface feature and moved inland over northern California. This forward stacking alignment signals weakening of the surface feature as the upper level convergence typically found upstream of the trough is now directly over the surface low. The WPC surface progs support this development, with the surface low weakening from 1016 mb as of 06Z to 1020 mb by 18Z. This evolution is an major hindrance to convection, and I've removed mention of thunderstorms from the forecast for today. That being said, the disturbance will still push trough over the next 12 hours, bringing some isolated areas of light rain and more widespread drizzle through the morning.

LONG TERM

Issued at 1252 AM PST Mon Mar 2 2026 (Tuesday through Sunday)

The long wave pattern is active this week. Following the trough today, a small ridge will build through Tuesday night before another, more neutrally tilted trough, moves through Wednesday. The precipitable water is probably too low to bring any appreciable rain, but this fast moving trough will bring a cold front followed by strong winds. Gale force gusts are possible along the coast and in higher terrain from Wednesday through Friday.

In addition to strong winds behind the front, the skies will quickly clear as much drier air moves in. The PW will likely drop from around 0.6" Wednesday morning to 0.3" Wednesday evening (roughly 75th percentile to 10th percentile for this time of year). This dry air mass is initially coming in from the NW behind the front. As the upper level flow evolves, an inside slider pattern is likely by Friday or Saturday. This will bring persistent northerly, offshore flow through the weekend. The combination of this dry air mass and adiabatic drying from the offshore winds will keep the relative humidity noticeably low, with mostly clear skies. Temperatures will also respond to this pattern, reaching the low to mid 70s next weekend.

Ensemble clusters more or less agree that the dry inside slider pattern will stay around in some fashion through the 9th or 10th, so we don't expect much if any rain in the long term forecast as we head towards the middle of the month.

AVIATION

(12Z TAFS) Issued at 316 AM PST Mon Mar 2 2026

A cloudy morning will transition to a clear afternoon. A weak disturbance is bringing some light showers to the area this morning, but the coverage and intensity is too low to include in the TAFs. This system is also supporting widespread MVFR to low VFR ceilings for all terminals. These clouds will persist through the morning before breaking up in the afternoon. Winds will be mostly gentle and diurnally driven. Ceilings will return overnight, with a lower height likely.

Vicinity of SFO...There are a few very light radar returns near the terminal, but the observer hasn't mentioned any precipitation yet. As such, I've decided to keep any mention of drizzle out of the TAF, but the threat remains through the next 6 hours or so. Otherwise the big question in the short term is whether the ceilings will drop back below the MVFR threshold. While there were a couple hours of roughly 1,500 ft ceilings, the current observation is at 4,700 ft. The probability of dropping back down has decreased, but I can't totally rule out a sunrise surprise that lasts for a few hours.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Despite the recent clearing, a much more robust cloud deck will soon move over the terminal and will persist through the morning hours. VFR conditions are likely through the afternoon and early evening hours before stratus returns around sunset.

MARINE

(Today through Saturday) Issued at 858 AM PST Mon Mar 2 2026

Gentle shifting winds today will become northwesterly this afternoon and increase to a moderate to fresh breeze Tuesday. Conditions will continue to deteriorate Wednesday through Friday with strong to gale force north winds developing across the waters. These winds will build very rough seas of 12 to 15 feet across exposed waters.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Small Craft Advisory from 3 PM Tuesday to 10 AM PST Wednesday for 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.

Small Craft Advisory from 2 PM this afternoon to 3 AM PST Tuesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.