, Issued at 112 PM PDT Thu Jun 18 2026 (This evening through Friday)
Stratus is receding across with the interior while it persists along the coast. Patchy clearing is expected along the coastline this afternoon before overcast conditions return this evening. A deep upper level trough moving into the West Coast is helping the marine layer to deepen and will bring a very low, but non-zero, chance of thunderstorms to far northern Sonoma and Napa Counties along the highest ridgelines. The marine layer is currently between 2000-2500 ft and is expected to remain around that depth through Friday. Given the deep marine layer and widespread cloud cover this morning, I continued to lower daytime temperatures for areas below 2000 feet today and again tomorrow. For Thursday, high temperatures will be in the 60s along the coast and 70s across the interior lower elevations. Areas above the marine layer will be warmer, with temperatures in the 70s to 80s. High temperatures on Friday will be slightly cooler with highs in the 60s along the coast and 70s across the interior. Breezy onshore winds (20-30 mph) are possible across the higher elevations and favored mountain gaps/passes (Altamont Pass, San Bruno Gap, Salinas Valley, etc).
A non-zero, but very low, chance of thunderstorms exists for far northern Sonoma and Napa Counties tonight into tomorrow. The current forecast shows a <5% chance of thunderstorms which is a decrease from yesterday. In terms of the environment, there is decent mid to upper level moisture but little to no instability. The bulk of the moisture and instability are to our north (EKA's CWA) and to our east (STO's CWA). There is a brief period where thunderstorm potential looks marginally more promising this evening across northern Sonoma/Napa Counties but even this is still a less than 5% chance. If a thunderstorm is able to develop, it is likely to be tied to the highest ridgelines along far northern Sonoma and Napa Counties. While thunderstorms remain unlikely, the more likely scenario is widespread drizzle along the coast. Precipitation will be light with totals amounting to less than a tenth of an inch. While this is not a lot of rain, it may be enough to wet coastal roads and make them slick. Drizzle is most likely overnight Thursday night into Friday morning which may impact any early morning commuters.
..issued at 112 PM PDT Thu Jun 18 2026 (Friday night through next Wednesday)
Below normal temperatures and troughing persist through the weekend before a pattern change takes place Tuesday/Wednesday of next week. Interior highs will be in the 70s on Saturday while coastal areas stay in the 50s to 60s. Temperatures start to rise Sunday into Monday with interior highs returning to the upper 70s to mid 80s while cooler weather persists along the coast. Upper level troughing will have progressed eastward by Tuesday with a strong upper level ridge replacing it. The center of this ridge will be over the desert southwest but it will bring a return of warmer temperatures to the Bay Area and Central Coast. The current forecast keeps the hottest weather across the interior Central Coast, Southern California, and the Central Valley where 90s to low 100s are possible. Temperatures across the Bay Area are forecast to reach the 80s to low 90s starting Tuesday. Confidence is low to moderate in the late week temperature forecast given the strength of the ridge and the relatively large model ensemble spread of forecast temperatures. Not currently anticipating record breaking heat from this ridge but would not be surprised if the forecast temperatures did go up slightly next week as this event gets closer in time. Probabilistic HeatRisk shows around a 15-20% chance of seeing Moderate HeatRisk mid next week across the interior Bay Area. This is definitely worth keeping an eye on and is a reminder that, despite our currently below normal temperatures, it is summer and temperatures are warming up. If you are participating in any outdoor activities, make sure to drink plenty of water and to take breaks in the shade as needed.
(06z TAFS) Issued at 935 PM PDT Thu Jun 18 2026
Breezy winds easing this evening though still persistent through the night into the day on Friday. Low clouds continue to fill much of the area terminals. MVFR will remain in place through tonight into the morning hours with slow clearing expected 16-20Z for areas closer to the coast. Confidence in marine layer depth and inland spread is moderate to high and should be similar to what was observed earlier this morning, potentially slightly deeper.
Vicinity of SFO, Breezy southwest winds subsiding after 08Z. The marine layer will begin to move back inland, with MVFR cigs around 1500-1700ft likely reaching the terminal by around 07-08Z with moderate confidence on timing and cig heights. Conditions will improve again after sunrise, with cigs forecast to erode by 16-18Z Fri.
SFO Bridge Approach, Lingering clouds over the bay may continue to reduce visibility overnight. Otherwise, conditions should be similar to SFO.
Vicinity of SJC and OAK, Low clouds near 1500ft will move into OAK over the next couple of hours with lower confidence in cigs near 2000ft reaching SJC in the 11-15z time frame. Typical diurnal winds expected on Friday.
Monterey Bay Terminals, Marine stratus will continue to fill in over the region with cigs near 1000-1500ft overnight into Friday. morning. Moderate confidence in clearing time on Friday near 19-20Z Fri.
(today through Tuesday) Issued at 849 PM PDT Thu Jun 18 2026
Fresh to strong winds have been gradually weakening and will continue into the night. Fresh to strong winds will return Friday afternoon and early evening leading to hazardous conditions for small crafts in the San Pablo Bay, San Francisco Bay, Suisun Bay and Monterey Bay. Expect slight to moderate chop along with the increasing afternoon winds each day. Southwesterly swell with light to moderate seas will continue into the weekend, with moderate west to southwest winds across the outer waters.
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!
Ca, Beach Hazards Statement through late Saturday night for CAZ006- 505-509-529-530.
PZ, Small Craft Advisory from 3 PM to 9 PM PDT Friday for Mry Bay-SF Bay N of Bay Bridge.
