textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1129 PM PDT Mon Jul 27 2026

- Breezy onshore winds expected each afternoon and evening through early midweek

- Gradual warming starting midweek, with Moderate HeatRisk for interior locations through the weekend

- Elevated fire weather threat across the interior North and East Bay, Diablo and Santa Lucia Ranges this week

- Hazardous beach conditions at the Pacific Coast with an increased risk for sneaker waves and rip currents through the end of the week

SHORT TERM

Issued at 1221 AM PDT Tue Jul 28 2026 (Today and tonight)

If you read the evening AFD update micro-climates were highlighted. Seems fitting to kick off this AFD with another micro-climate highlight. If one looks at the overnight satellite imagery they'll notice only patchy stratus developing. I do expect more by morning, but patchy for now. So why is it patchy, pockets of offshore flow most notably over the N Bay and along the Big Sur coast. Offshore flow is a drying and warming wind for our region. Taking a closer look at Big Sur there are two sensors called Highlands Peak. It's close to midnight and both are reporting temperatures near 80 degrees. N to NE flow leads to compressional warming as the air descends the Santa Lucias, hence the warm temperatures.

Tuesday will be another pleasant day weather wise most areas. The longwave pattern continues to advertise broad upper level troughing just offshore and upper level ridging to the SE. Similar to Monday we'll see a large spread of temps from the coast to the interior. Onshore flow will keep coast/bays in check with highs in the 60s/70s. Farther inland with marine layer influence will see much warmer temperatures with highs in the upper 80s to near 100.

Given the temperature contrast expect another round of breezy afternoon winds in the valleys and inland gaps/passes.

Tuesday night the upper level trough begins to ease with upper level ridging building in from the east. As such, a more stable marine layer will develop with slightly better stratus coverage. Above the marine layer temperatures will be on the milder side.

AVIATION

(06Z TAFS) Issued at 1045 PM PDT Mon Jul 27 2026

Similar satellite trend as 24hrs ago with limited stratus impacting terminals with the exception of KHAF. Like the previous few nights, stratus is expected to push inland, though with a weaker SFO-SAC gradient as last night. Leaning closer towards pre-dawn hours for VFR/IFR ceilings to set in, with clearing times a little earlier than normal diurnal trends for this time of year, by mid-late morning Tuesday.

Vicinity of SFO...VFR through the remainder of this evening into the overnight hours. A steady fetch of onshore flow going into the overnight is expected to produce MVFR ceilings as stratus eventually fills in through the San Bruno Gap and around the Bay Shore. The unorganized nature of the marine layer should allow for clearing by late morning, with gusty onshore winds in the afternoon.

SFO Bridge Approach...Similar as SFO

Monterey Bay Terminals...VFR through the remainder of the evening with MVFR/IFR ceilings expected after midnight with a slight chance of stratus filling in sooner than that. As is the case with potentially filling in sooner than forecast tonight, there is a slight chance of ceilings lingering longer than mid-late morning Tuesday depending on whether a weak fetch of offshore flow just above the marine layer develops or not.

MARINE

(Tonight through next Sunday) Issued at 1045 PM PDT Mon Jul 27 2026

Fresh to strong northwest breezes will persist through the week into next weekend, especially across the outer waters. Coastal jet regions along Big Sur and Point Reyes may result in frequent gale force gusts. Moderate seas will become rough by the middle of the week with the increasing northwest winds. Tropical storm activity will continue to produce long period southerly swells along our coastal waters into the weekend.

FIRE WEATHER

Issued at 152 PM PDT Mon Jul 27 2026

The elevated fire weather threat will persist across portions of the area through mid-week. Overnight RH recovery will remain moderate at locations at or above 2,000 feet with values around 40 to 50 percent. This will be particularly true across the Mayacamas, highest peaks of the East Bay Hills, the Diablo Range, Santa Cruz Mountains, 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. Afternoon RH will remain critically dry with values between 20 and 40 percent, with far southern portions of the interior Central Coast potentially seeing min RH near 10 percent. Energy Release Components (ERC) are projected to climb above the 95th percentile across the interior Central Coast. Individuals across the area 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.

BEACHES

Issued at 145 PM PDT Sun Jul 26 2026

Distant tropical cyclones in the Eastern Pacific will continue to generate 16-18 second (long-period) southwesterly swell which has reached the coastline of the San Francisco Bay Area and Central Coast. As such, sneaker waves and strong rip currents are the primary concerns. Breaking waves can reach up to 12 feet along some south and southwest facing beaches and break points, such as Santa Cruz, Pacifica, and parts of Stinson or Ocean Beach. This can be particularly surprising when wave heights increase suddenly after a period of seemingly tranquil wave action. In fact, sneaker waves can have 20+ minutes in between the larger sets (breaking waves) with significant "flat/calm looking" times between them. Due to the long period, sneaker waves are powerful and can catch beachgoers by surprise, resulting in people and pets being swept into the cold, turbulent ocean. Rip currents are strong enough to pull even the strongest swimmers away from shore. Check marine conditions before you head out! Swim near a lifeguard, if possible. Maintain a safe distance from the water, and stay away from jetties, piers, beachside rocks, and other waterside infrastructure. Never turn your back to the ocean and if you have small children or pets at the beach, please keep an eye on them. Hazardous beach conditions are anticipated to persist through Saturday afternoon.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement through Saturday afternoon for CAZ006- 505-509-529-530.

PZ...Small Craft Advisory from 2 PM to 9 PM PDT Tuesday for Mry Bay- SF Bay N of Bay Bridge.

Small Craft Advisory until 3 AM PDT Wednesday for Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory until 3 PM PDT Thursday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.

Gale Warning until 3 PM PDT Wednesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.