textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 156 PM PDT Wed Jun 17 2026

- Minor coastal flooding due to higher than normal high tides anticipated across low-lying coastal areas.

- Hazardous beach conditions as well with increased risk of sneaker waves and strong rip currents.

- Minor HeatRisk through the end of the week with temperatures cooling to below normal.

SHORT TERM

Issued at 156 PM PDT Wed Jun 17 2026 (This evening through Thursday night)

The marine layer, ~1500ft, continues to retreat back towards the coast, having lingered a bit longer than expected for the San Francisco Bay and into the northern interior valley, bringing slightly cooler high temps for today. Expect the marine layer to push back onshore tonight. Have included drizzle along the coast as the marine layer slightly deepens as the ridge breaks down as troughing pushes east towards the coast. Patchy fog for interior valleys possible as well. The slight cooling trend will continue into Thursday, especially for interior locations, as a result of the troughing and slightly stronger onshore flow, with afternoon highs in the 60s along the coast to mid 70s to 80s for interior locales. The marine layer builds to ~2000kt and expands further inland for tomorrow night, with more fog and drizzle expected.

Tidal flooding continues across low-lying coastal and Bayshore areas through Thursday morning as high astronomical tides combine with surge effects from wind, swell, and thermal expansion to bring us the highest tides of the summer season. High tide is expected to be 1.2 ft above normal (7.1 ft MLLW) at 1:51 AM on Thursday. In addition, the long-period southerly swell continues, which increases the risk for sneaker waves and strong rip currents, with a Beach Hazards Statement out through late Friday night. See the BEACHES section for more information, but the main takeaway is to never turn your back to the ocean!

LONG TERM

Issued at 156 PM PDT Wed Jun 17 2026 (Friday through Wednesday)

The trough will begin to move onshore on Friday and pass over the region through the weekend, with the cooling trend continuing. Shower and thunderstorm potential associated with the trough will stay primarily over the higher terrain to the north and east of the area as a deep marine layer greatly inhibits any thunderstorm potential. However, there will be enough elevated instability for cumulus development and around a 5% chance of thunderstorms across far northern Napa and Sonoma counties Thursday night and Friday with lower chances to the south.

The marine layer will likely deepen as the trough passes through, with the cooling trend continuing through Saturday. Afternoon highs temps will only reach the 70s to low 80s for interior location and upper 50s to mid 60s along the coast. The onshore flow will continue with breezy afternoon winds. Coastal areas will could continue to see drizzle.

By Sunday, the trough is expected to weaken as model guidance is suggesting a ridge building across the western US into next week. This will bring a warming trend, beginning Sunday into next week, with a return of some 90s and moderate HeatRisk concerns by midweek for some interior areas.

AVIATION

(06Z TAFS) Issued at 958 PM PDT Wed Jun 17 2026

MVFR-IFR stratus is expanding into the valleys and will impact most terminals through the night as the breezy and gusty southwest pattern winds continue to diminish, with low to moderate confidence in stratus impacts at LVK and SJC, where the marine layer is thick enough to bring stratus into both terminals but the lower level southwest flow may inhibit stratus flow into those areas. The night shift will monitor conditions through the night. Stratus should retreat to the coastal areas through Thursday morning and the breezy and gusty southwest pattern winds should resume in the afternoon.

Vicinity of SFO... VFR with breezy and gusty southwest winds at the terminal through the next few hours. Due to the downslope flow, have pushed back the MVFR-IFR stratus impacts to around 10Z. Stratus will dissipate through Thursday morning with breezy southwest winds returning to the terminal in the afternoon. Stratus will return to the terminal area late Thursday night.

SFO Bridge Approach... Lower confidence of stratus impacts tonight with the large scale southwest flow, as high resolution models tend to keep the stratus deck away from the approach path. Otherwise similar to SFO.

Vicinity of OAK and SJC... IFR stratus through the night at OAK, with breezy west winds diminishing through the next couple of hours. At SJC, the stratus forecast remains low confidence. High resolution model output keeps the terminal area clear, but places scattered MVFR stratus in the vicinity and particularly to the north of the terminal. If stratus does impact the terminal, the most likely timing is from 11-15Z. Stratus clears out through Thursday morning as breezy and gusty winds return to the terminals, with west winds developing at OAK, and southwest winds developing at SJC. Stratus returns to OAK late Thursday night.

Monterey Bay Terminals... MVFR stratus has flowed over SNS and will remain through the night. At MRY, large scale southwest flow has sheltered the terminal from the larger stratus deck, defying much of the high resolution model output, but a patch of stratus developing to the immediate southeast of the terminal suggests that the ceilings are close by. Stratus will retreat to the immediate coast Thursday morning and will return to the terminals Thursday evening. Breezy winds will diminish through the night before resuming on Thursday afternoon with strong gusts and a turn from a southwest wind at MRY and a northwest wind at SNS.

MARINE

(Tonight through next Tuesday) Issued at 958 PM PDT Wed Jun 17 2026

West to southwest winds driven by a weak low pressure system in the northern outer waters will remain gentle to moderate overnight. Winds increase again for the next couple afternoons and evenings with strong breezes anticipated, leading to hazardous conditions for small craft. Light to moderate seas with southwesterly swell will continue into the weekend. Moderate west to southwest winds and moderate seas will prevail over the open ocean into the weekend.

BEACHES

Issued at 156 PM PDT Wed Jun 17 2026

Long period southerly swell at around 15 to 17 seconds will persist through early Saturday as energetic storms in the Southern Hemisphere continue to affect the California coast, especially for south and southwest facing beaches. Hazardous beach conditions are advertised, specifically for moderate to steeply sloped beaches along the Pacific Coast of the North Bay, San Mateo, Santa Cruz counties. A Beach Hazards Statement for Pacific Coast beaches continues through late Friday night. Be sure to check beach conditions before you head out. Sneaker waves will run up the beach much farther than other waves, potentially catching beachgoers by surprise and resulting in people being swept into the water. Rip currents are strong enough to pull the strongest swimmers away from shore. Swim near a lifeguard if possible. Stay back from the beach, and away from jetties, piers, beachside rocks, and other infrastructure near the water. Never turn your back to the ocean!

MTR WATCHES/WARNINGS/ADVISORIES

CA...Beach Hazards Statement through late Friday night for CAZ006-505- 509-529-530.

Coastal Flood Advisory until 5 AM PDT Thursday for CAZ006-506- 508.

PZ...Small Craft Advisory from 3 PM to 9 PM PDT Thursday for Mry Bay- SF Bay N of Bay Bridge.