textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 216 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

- Elevated fire weather threat across the 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

UPDATE

Issued at 821 PM PDT Mon Jul 27 2026

While the Bay Area weather may not be known for notable weather like tornadoes, thunderstorms, or hurricanes on the regular it definitely shines in the micro-climate department. Today was no exception for micro-climates. The juxtaposition between the coastal temperatures and inland temperatures was pretty impressive. The inland heat was triggered by a warm airmass aloft and a ridge of high pressure to the east. However, the natural AC/cooler coastal temps were due to onshore flow and a trough of low pressure off the coast. For context, in Monterey county alone max temps struggled to reach 60 and topped out at 59 degrees along Big Sur, but a short jump eastward over the Santa Lucia Mts max temps made a run for 100 and topped out at 98. Almost a 40 degree spread in a short distance. Elsewhere around the Bay Area and Central, while not as extreme, we did see temps in the 60s/70s near the coast/bays and upper 70s to 90s inland.

For tonight, expect another night of some marine layer stratus to develop. Not widespread, but enough to impact the coast and bays. Should note that some hi-res guidance does suggest areas of offshore flow. That will limit stratus coverage as well. Additionally, the offshore flow could keep a few spots warmer and drier than forecast like the N Bay Mts and Santa Lucia range.

No update need for now.

MM

SHORT TERM

Issued at 216 PM PDT Mon Jul 27 2026 (This evening through Tuesday night)

Pleasant conditions persist this afternoon across the Bay Area and Central Coast. 24 hour tendencies in temperatures indicate most areas are running anywhere from 1-4 degrees lower than this time yesterday. While the stratus footprint has dwindled to the San Mateo coastline, persistent onshore flow is likely the culprit for the cooler conditions. As troughing continues on Tuesday, we'll contend with another period of onshore flow. There's some uncertainty with regard to the inland extent of marine stratus, but overall, mostly sunny skies are anticipated late morning and into the early afternoon on Tuesday.

LONG TERM

Issued at 216 PM PDT Mon Jul 27 2026 (Wednesday through next Sunday)

Wednesday will be the start of our warming trend. The region will be on the backside of the aforementioned upper level trough with the Pacific Southwest Ridge projected to gradually expand westward Wednesday and into Thursday. While another compact upper level wave will move eastward onto the Oregon Coast late Thursday, it's impact on our weather seems to be an increase in the winds over the marine environment thanks to the development of several coastal jet features. This, in theory, could help induce upwelling which may promote marine stratus development. However, forecast soundings from traditional NWP along with cross- sections from the PG&E/SJSU WRF indicate the marine layer compressing to under 1000 feet (potentially lower through the end of the week). As such, infiltration of marine stratus should be limited spatially and at a minimal if at all. If stratus does develop, it'll likely dissipate rather quickly by mid to late morning. This promotes moderating temperatures, particularly across the interior and poor to moderate humidity recovery (30-50%) at elevation. More intel on this in the fire weather section below.

Temperature wise, guidance remains in fair agreement with moderating conditions on Wednesday and into the weekend across the Bay Area and Central Coast. We still maintain some very diffuse troughing aloft on the synoptic scale, but the ridge expands more noticeably Thursday and into the weekend. Confidence has increased that the ridge will expand sufficiently enough to compress the marine layer, particularly across the Central Coast where the areal extent of Moderate HeatRisk increases quickly. There's still a chance that current MaxT forecasts may need to be trended upward across interior sections, but likely only on the order of 1-3 degrees. Across the Santa Lucia and Galiban Ranges, pockets of Major HeatRisk enter the forecast with some on Wednesday, but especially Thursday and into the weekend. Those recreating across this region should ensure they are adequately hydrated with plenty of water and have access to shade. Moderate HeatRisk becomes most expansive Thursday and into Friday across the remainder of the Central Coast and this is when the potential for more formal heat products increases.

While there's strong consensus for hot conditions across the interior, coastal regions, including the population centers, model forecasts exhibit a much more significant spread. For instance, the KSFO MaxT interquartile ranges from the mid-60s on the low end to low to mid-80s on the high end Thursday and into the weekend. What will likely modulate just how hot it gets for coastal locations will be onshore vs. offshore flow. 925mb flow in the deterministic guidance starts to diminish especially Friday and into the weekend. As flow drops below 10 knots, there's the potential for a large degree of variability in direction and should a given location experience periods of either very weak onshore flow or offshore winds, MaxT will likely verify on the higher end of the spread. In the case of KSFO, mid-80s would be nearly 10-15 degrees warmer than normal. For now the forecast currently resides on the warmer end of things through at least Thursday, but additional adjustments will be made as we venture closer to mid- week. Regardless, it'll be important for those across the area to remain hydrated with plenty of water, stay cool and limit strenuous outdoor activities to the cooler portions of the day. Never leave kids or pets unattended in vehicles! In addition, if headed to our Pacific coast beaches for relief, be mindful of the increased risk for sneaker waves and rip currents.

AVIATION

(00Z TAFS) Issued at 456 PM PDT Mon Jul 27 2026

VFR with clear skies except for some spotty stratus directly along the coast near KHAF. The theme remains mostly the same as we continue to be at the intersection of a broadening ridge to the east and persistent troughing over the EPAC. Good confidence that North Bay terminals will see little to no stratus through the forecast period. Lower confidence for the coastal areas where the marine layer is expected to continue to be more unorganized than usual this time of year.

Vicinity of SFO...Low confidence in whether ceilings will develop after midnight into the pre-dawn hours. Dry air aloft and potential for weak offshore flow aloft may result in just spotty, less impactful stratus development Tuesday morning, with clearing expected by late Tuesday morning.

SFO Bridge Approach...Similar as SFO.

Monterey Bay Terminals...Higher confidence in stratus eventually developing farther south into the Monterey Bay terminals with less dry air mixing down to the surface less potential for offshore flow aloft locally. Expect some stratus to develop after sunset but remain VFR until later in the night when it begins to fill in across the bay into the Salinas Valley. Expect VFR conditions for the remainder of the TAF period once ceilings lift.

MARINE

(Today through Saturday) Issued at 947 AM PDT Mon Jul 27 2026

Fresh northwesterly breezes increase to strong today, persisting through the week with frequent gale force gusts along the Big Sur and Point Reyes coastal jet regions. Moderate seas build to rough in the outer waters by tomorrow and continue through the week. Distant tropical cyclones continue to send long period southerly swells our way through the work week.

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 until 9 PM PDT this evening for Mry Bay-SF Bay N of Bay Bridge.

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.