, Issued at 1219 PM PDT Tue Jul 21 2026 (This evening through Wednesday night)
Have went ahead and issued a Heat Advisory through 9 PM this evening for interior areas of the Bay Area and Central Coast. Temperatures overnight and into this morning didn't cool off as much as originally expected, thanks to the mid/upper level cloud cover across the region. That combined with temperatures forecast to reach the 90s (potentially exceeding 100 deg F in the warmest interior spots) across the interior made for widespread Moderate HeatRisk. Today is forecast to be the hottest of the week!
For tonight, expecting an increase in low level stratus to return to the coast and expand inland into the coastal adjacent valleys. There is a greater than 50% probability of this occuring as mid- to-high level clouds begin to shift to the east as remnant moisture from Elida gets absorbed in the mean flow aloft. Cannot rule out coastal drizzle tonight, depending on if the shallow marine layer is able to redevelop. It will feel muggy once again tonight as humidity remains elevated.
Tomorrow will feature a significant cool down thanks to an increase in onshore winds and stronger marine influences. Temperatures across the interior will warm into the mid 70s to mid 80s with the warmest interior spots reaching into the lower 90s across the Central Coast. Meanwhile, cooler conditions will prevail near the coast with day time highs in the mid 60s to mid 70s.
..issued at 1219 PM PDT Tue Jul 21 2026 (Thursday through next Monday)
Not much change to the forecast beyond the short term. Still expecting troughing off of the Pacific Northwest coast as high pressure remains over the interior West through late week. This will generally keep conditions near seasonal averages with night/morning low clouds working their way inland and then retreating to the coast by the afternoon. As the high pressure appears to shift more toward the Four Corners region, we may see the marine layer compress over the weekend with a slight inland warming trend.
(06z TAFS) Issued at 959 PM PDT Tue Jul 21 2026
After a hot and clear day with widespread VFR, marine layer stratus appears to be returning with a vengeance. Stratus associated with an offshore surface low has begun spilling over the coastal ranges, and pushing through the gaps and valleys of the Bay Area, Monterey Bay and the Salinas Valley. Expect MVFR ceilings with onset, and low confidence of timing or extent of IFR/LIFR through the overnight hours.
Vicinity of SFO, Stratus making a steady push through the Golden Gate and spilling over the San Francisco peninsula coastal range. The progression is faster than previous guidance indicated but still don't expect MVFR/IFR ceilings until after midnight. Expect breezy onshore winds at times overnight increasing by Wednesday afternoon. MVFR/IFR ceilings are expected to lift by early afternoon.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Stratus accelerated through Monterey Bay into the Salinas Valley after sunset and has already settled in with a MVFR ceiling at KSNS. The northwest onshore flow currently at KMRY is holding off the easterly push of stratus for the moment, however the stratus should fill in shortly over the terminal. Expect clearing to VFR by early afternoon, until sunset when stratus ceilings return.
(tonight through next Monday) Issued at 959 PM PDT Tue Jul 21 2026
Gusty southerly winds over the inner coastal waters and across the San Francisco Bay to the Delta will continue tonight. Otherwise west-northwest breezes tonight will gradually increase through the morning into Wednesday afternoon become northwest with fresh to moderate breezes continuing into the weekend. Moderate southwesterly swell from tropical cyclone activity in the Eastern Pacific will bring mixed seas with potentially hazardous conditions through the weekend.
Ca, None. PZ, Small Craft Advisory until 3 AM PDT Wednesday for SF Bay N of Bay Bridge.
Small Craft Advisory from 9 PM Wednesday to 9 PM PDT Thursday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
