, Issued at 1200 AM PDT Fri May 22 2026 (Today and tonight)
The stratus deck has completely covered the coast and is flowing through the Petaluma Gap into the Sonoma County valleys, through the Golden Gate into the Berkeley area, and across the Monterey Bay region and up the Salinas Valley. The Bodega Bay profiler reports a marine layer around 1000-1500 ft thick, which would allow stratus to fill into the North Bay Valleys, the East Bay west of the Berkeley- San Leandro Hills, the Santa Clara Valley, and perhaps impacting the area around Hollister over the course of the night before stratus retreats to the immediate coast through the post-sunrise hours this morning.
An upper level ridge over the northern Pacific that extends into the Pacific Northwest is continuing to flatten under the influence of a trough centered over Alaska, allowing a gradual cooling trend to begin today. NBM model output continues to run a little warm, so I have tamped down today's high temperature forecasts. They're still a shining example of the impact of the Bay Area and Central Coast's famous microclimates, with high temperatures ranging from the middle 80s to the lower 90s in the inland valleys of the Bay Area and Central Coast, to the upper 50s to lower 60s along the Pacific Coast. In between the two are the North Bay valleys, where highs range from the middle 70s to lower 80s, the Bayshore regions where highs range in the 70s, tending warmer the closer you get to the southern edge of San Francisco Bay, and downtown San Francisco itself where temperatures top out around the middle 60s. Breezy onshore winds will develop during the afternoon and evening hours, with gusts up to 15 to 25 mph through favored gaps and passes.
Continuing hot and dry conditions across the interior regions will contribute to another day of elevated fire weather concerns. For those living or visiting those hot and dry regions, keep the following in mind:
* Properly dispose of cigarettes and matches * Do not use a lawn mower on weeds or dry grass * Avoid using equipment that creates sparks * Make sure campfires are completely put out * Make sure no vehicle parts drag on the ground, including towing chains * Obey burn bans & only burn with a permit
..issued at 1200 AM PDT Fri May 22 2026 (Saturday through Thursday)
The aforementioned cooling trend continues through the early part of next week, and by Saturday, temperatures should be near the seasonal average with highs in the middle 70s to the middle 80s inland. Early next week, a cold front associated with a deep upper low is expected to make its way through the region, and the ensemble model runs are starting to agree on a period of cooler temperatures and stronger onshore flow Monday through Wednesday. The slight chance for light rain or drizzle continues across favored coastal regions as the front passes through, as is the concurrence of the models that any rainfall that develops will be very light with few hundredths of an inch being a reasonable higher end amount for any region.
Towards the later part of the week, the ensemble model runs begin to diverge as the evolution of the upper level low and incoming ridging becomes uncertain. Most runs lean towards a warming trend for that period, which is reflected in the current forecast, with a significant minority (around 30-40% of the runs) suggesting that some form of trough lingers through the period.
(12z TAFS) Issued at 450 AM PDT Fri May 22 2026
Solid marine layer push overnight, one of the bigger pushes as of late. That being said, LVK and SJC have the best chc of remaining VFR this AM. The marine layer may have solid intrusion, but still remains on the shallow side. Expect mid to late morning clearing most areas except the immediate coast. VFR this afternoon with early return this evening and overnight. Low conf remains on CIGs for LVK and SJC again tonight.
Vicinity of SFO, Tricky and low conf forecast this morning as the terminal is in a stratus deck hole with clouds on the periphery creeping inward. Hi-res and prob guidance shows a slight chc (20-30%) of CIGs arriving in the 12-13Z time and clearing 16-17Z if they do arrive. If CIGs do come they'll be low and under 1k ft. Given the lower conf and transient nature went with a 4 hr tempo. VFR this afternoon. Conf is low again for tonight as guidance shows a similar scenario again.
SFO Bridge Approach, Way more clouds over the approach into the AM rush. It'll be close, but aircraft may hold onto visuals until the bridge and possibly make it to the runway. Cloud bases are under 1k and marine layer detection shows cloud tops in the 1200-1500ft.
Monterey Bay Terminals, LIFR cig mid morning then VFR. Early return of CIGs this evening.
(today through Wednesday) Issued at 426 AM PDT Fri May 22 2026
Northerly breezes winds will continue to ease north of Point Reyes today. Elsewhere winds will shift to southwesterly and remain light to gentle. The sea state will improve heading into the holiday weekend as northwesterly swell continues to decrease.
Ca, None. PZ, None.
