textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1220 PM PDT Sat Aug 1 2026

- Moderate HeatRisk in the interior through Monday with some patches lingering through the next week

- Near critical fire weather threat across the interior North and East Bays, and the Diablo and Santa Lucia ranges through Monday

- Hazardous beach conditions across the Pacific Coast with an increased risk for sneaker waves and rip currents through the afternoon

- Strong and gusty winds develop over coastal waters north of Pt Reyes through Sunday

UPDATE

Issued at 909 AM PDT Sun Aug 2 2026

Another day, another Otter Eddy over Monterey Bay as the stratus continues to linger across the coastal plains and into the northern Salinas Valley. Patches of stratus also linger along the San Mateo Peninsula coastline. Otherwise, the rest of the region is clear and the forecast is on track.

DialH

SHORT TERM

Issued at 208 AM PDT Sun Aug 2 2026 (Today and tonight)

An upper level disturbance will pass over the PacNW today, with quasi-zonal flow to weak troughing setting up over northern CA. To our southwest west, high pressure is being suppressed over the Desert Southwest and southern CA. What does that mean for us in the short term? Well, it means the marine layer will remain compressed as a result, at about 500ft and hugging the San Mateo and Central Coast line which means cloudy skies, patchy dense fog, and perhaps coastal drizzle through the mid morning. Skies will then clear, leading to a mainly sunny day across the region. Moderate HeatRisk is expected today for interior locations where temperatures reach the mid 90s to low 100s. Elsewhere, temperatures rise into the low 70s to mid 80s unless you're immediately along the coast where temperatures 60s.

LONG TERM

Issued at 208 AM PDT Sun Aug 2 2026 (Monday through Saturday)

Little change for Monday as the aforementioned upper level trough pushes east, allowing the pattern to change from quasi-zonal and troughy to quasi-zonal with high pressure building in. The forecast will essentially be on repeat, with perhaps interior temperatures warming up a few degrees. Heading into midweek, there are a few items that could affect temperatures. The first being onshore flow ushering in some cooler air; however, it will be dependent on how quickly the high builds in. If it is able to build, 850mb temps look to be fairly warm in the deterministic guidance. This means temps may need to be bumped up a few degrees inland instead of showing a subtle cooling trend. Beyond that high pressure looks to build and hold leading to a warming trend for late week and into the weekend.

AVIATION

(12Z TAFS) Issued at 429 AM PDT Sun Aug 2 2026

VFR everywhere except the coast where patchy stratus is filling in over the Monterey Bay and San Mateo coastline. Given the compressed marine layer, highest confidence in patchy IFR to LIFR CIGs along the coast with stratus not expected to extend inland. High pressure will keep the marine layer compressed again tonight and see a late return of stratus along the coast. Currently not expecting stratus to extend inland tonight due to the compressed marine layer. Breezy onshore winds return this afternoon before winds decrease overnight.

Vicinity of SFO...VFR. The marine layer remains compressed due to high pressure which will prevent stratus from extending inland. Guidance shows some potential for patchy stratus to reach SFO early this morning (12-16Z) but confidence is low that this will occur. Breezy northwesterly winds expected this afternoon/evening before winds decrease overnight.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...IFR to LIFR conditions expected this morning. Some potential for patchy fog to impact MRY this morning with visibilities decreasing to around 1-2SM. Conditions improve by late morning with VFR through the afternoon. There is mixed confidence on tonight's stratus return. Ensemble guidance again suggests a later return is likely at both sites with the HRRR suggesting both sites could stay VFR through much of tonight. This scenario cannot be fully written off due to how compressed the marine layer is and the potential for high pressure to fully mix out the marine layer. For the 06Z TAFs, leaned on persistence to have stratus return late tonight but this may need to be amended in future TAF issuances.

MARINE

(Today through Friday) Issued at 909 AM PDT Sun Aug 2 2026

Northwest winds remain strong to near gale today and diminish to moderate by Monday night. Northern waters continue to have frequent gale force gusts into early Monday morning. Wind driven rough to very rough seas (9-15 feet) hang on through Tuesday morning while gradually subsiding to moderate (4-8 feet) through Friday.

FIRE WEATHER

Issued at 452 AM PDT Sat Aug 1 2026

Near critical fire weather conditions are expected through the weekend and potentially into next week. Temperatures remain around 10 to 15 degrees above normal across the interior through early next week with highs in the upper 80s to 90s. No major changes to the forecasted dry conditions. Daytime humidity retention remains poor across the interior (25-30%) with humidity values dropping into the 10s across the interior Central Coast, East Bay Hills/Valleys, and the higher elevations. Portions of the interior Central Coast may see daytime humidity values drop into the single digits this weekend into early next week. Overnight RH recovery remains poor at locations above 2,000 feet with values between 25 to 40% expected with some favored locations struggling to reach even 25%. This will be particularly true across the Mayacamas, highest peaks of the East Bay Hills, the Diablo Range, the Santa Cruz Mountains, the Santa Lucia and Gabilan Ranges. Nocturnal drying (rapid decrease in RH through the pre- dawn hours) may also transpire which will increase the burn period or time in which fire behavior may remain active. Energy Release Components (ERC) are projected to climb above the 97th percentile across the interior Central Coast and Mid Coast to Mendocino (North Bay) zone. ERC values are rapidly climbing across the Diablo-Santa Cruz zone (Diablo Mountains and Santa Cruz Mountains) with values approaching the 97th percentile by next week. Diurnally breezy onshore winds are expected along the coast, mountain gaps and passes, and along the ridgelines each afternoon/evening. With near critically dry conditions and above normal temperatures expected, individuals across these areas are advised to avoid activities that may spark a fire. Fire crews are urged to exercise extra caution when executing any prescribed burns, especially where fuels, topography, and weather align.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...Gale Warning until 9 PM PDT this evening for Pt Arena to Pt Reyes 0-10 nm.

Gale Warning until 3 AM PDT Monday for Pt Arena to Pt Reyes 10- 60 NM.

Small Craft Advisory until 3 PM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM.