, Issued at 200 PM PDT Thu Aug 6 2026 (This evening through Friday night)
Seeing a lot of similarities today to the last few days, the marine layer foot print from this morning is dictating the "cooler" temps and the hotter inland temps. Latest 24 hr trends follow this foot print too showing slightly warmer temperatures this afternoon across the interior.
For tonight, a little bit of rinse and repeat. Marine layer hugging the coast will once again March inland with a slight compression, but still decent inland reach. Nocturnal drying and active thermal belts persist above the marine layer exacerbating the fire weather concerns.
Monsoon moisture influx is slowing creeping in from the south as we speak. Latest guidance continues to show increasing moisture through Friday. Normally, focus would turn toward high based convection, but the large ridge and lack of trigger will like limit convective potential. Also, the moisture seems to be rather high (>10k ft) so impacts at the surface may be minimal.
Friday and Friday night, large upper level ridge will expand back over the region bringing a more noticeable warm up across the interior. For the coast, same old same old, persistent marine layer influence keeping temperatures in check.
..issued at 230 PM PDT Thu Aug 6 2026 (Saturday through next Wednesday)
First and forecast, a Heat Advisory has been issue for Saturday and Sunday. The warming trend will continue Saturday and then moderate Sunday. The warmer interior temperatures in the mid 90s to lower 100s will push HeatRisk back into the critical levels (widespread Moderate to pockets of Major). Overnight lows will remain mild and in the 60s to mid 70s for interior and higher terrain locations. There are lots of outdoor events going on around the Bay Area this weekend. Interior locations will want to take some safety precautions for the heat: hydrate, take breaks, seek shade, never leave pets/people in cars. Do expect a warm up at the coast too, but it's the Bay Area so pack a jacket as the marine layer will move inland during the evening hours.
HeatRisk concerns begin to fade on Monday as the large ridge flattens and looks to split into two with sagging H5 over CA coast. The cooling trend will continue through at least Wednesday.
(00z TAFS) Issued at 410 PM PDT Thu Aug 6 2026
MVFR-IFR stratus lingers at the immediate coast, with VFR conditions predominant everywhere else and a few high based clouds drifting northwards to the south of MRY and SNS. Gentle to moderate onshore flow continues into the evening hours. Tonight, MVFR-IFR stratus will return to the coastal valleys with low to moderate confidence that impacts extend into the interior East Bay. That may depend on exactly how deep the marine layer is overnight. Moderate confidence on the timing of the stratus return with a few models indicating somewhat later development of ceilings. Opted to maintain consistency with the previous issuance for now. Stratus is expected to mix out back to the immediate coastline Friday morning with the breezy onshore winds expected to resume in the afternoon.
Vicinity of SFO, VFR into the late evening hours with moderate and gusty northwest winds. Winds will diminish overnight as low-end MVFR stratus comes into the terminal area sometime around 04-08Z. High resolution models are putting the edge of the stratus deck right over the terminal during this timeframe, leading to lower confidence on the exact timing. Stratus will gradually mix out through Friday morning followed by breezy and possibly gusty northwest winds in the afternoon and evening hours.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR through the afternoon and early evening as gentle to moderate onshore winds continue. IFR-MVFR stratus will build sometime around 03-06Z and persist through late Friday morning. Some models are tilting later in terms of the time of stratus development so confidence in timing is moderate to low. Stratus will retreat to the coast late Friday morning with gentle northwest winds developing in the afternoon hours.
(tonight through next Tuesday) Issued at 410 PM PDT Thu Aug 6 2026
Northwest gentle winds gradually increase to a fresh to strong breeze (20-25 kt), particularly across the outer northern waters on Saturday. Moderate northwest seas around 4-8 feet also increase to rough (9-11 feet) by Sunday morning. Winds and seas remain elevated through the middle of next week. A long period southerly swell (15- 17 seconds) will impact our coastal waters beginning Saturday morning.
Ca, Heat Advisory from 10 AM Saturday to 10 PM PDT Sunday for CAZ503- 504-510-512>515-517-518.
PZ, None.
