, Issued at 1053 PM PDT Sat Aug 29 2026 (Tonight through Monday)
Saturday was a beautiful sunny day across the Bay Area and Central Coast and we'll get more of the same on Sunday. The marine layer stratus fully evaporated by noon as a much direr air mass moved in from the north. The 00Z weather balloon measured the precipitable water at 0.58", which is around the 10th percentile for this time of year. With unimpeded radiative cooling, marine layer stratus is starting to reform, with Half Moon Bay recording the first clouds overhead this evening. Coastal areas south of the Golden Gate will likely see the stratus come back before the Sun rises Sunday morning. Inland valleys are more of a toss-up. The marine layer is currently 1,600' deep and will gradually expand over the next 24 hours. Any clouds that form will likely clear by midday with a mild, breezy, and clear afternoon.
Marine layer stratus should be much better organized by Monday morning. The depth will likely be around 2,000' by then, with less chance of clearing along the coast. As a short wave trough moves through, temperatures will also be around 5 degrees cooler than the weekend with a stronger onshore breeze in the afternoon.
..issued at 1053 PM PDT Sat Aug 29 2026 (Monday night through next Saturday)
As the troughing pattern continues, the 850 mb temperature will bottom out around 6-10 C on Tuesday. That's about as low as it gets this time of year and more like a normal November day. High temperatures will be in the 60s and 70s with the typical marine layer stratus in the morning. The troughing pattern will deepen and a cut-off low will bring some early rain to the Pacific Northwest later this week. There is a chance for some light rain to make it as far south as the North Bay starting Tuesday. The ECMWF ensemble mean shows a few hundredths at Santa Rosa from Tuesday through Friday, with a 10% chance of reaching 1/2". The probability drops quickly further south outside of some marine layer drizzle along the coast. This cut-off low now looks like it will linger near Northern California into the weekend. If so, this low pressure breaks up the normal subtropical high and opens the door for tropical cyclones and the associated moisture to recurve to the north rather than being held in the tropical latitudes. While it's too early to say if that will happen, the persistent troughing pattern looks like it may keep the door open into next week.
(12z TAFS) Issued at 432 AM PDT Sun Aug 30 2026
Scattered IFR-MVFR stratus is developing across the coastal and Bayshore SF Bay Area and parts of Monterey Bay. The scattered and radiational cooling-driven nature of the stratus development is making it difficult to predict where stratus will develop through the rest of the night, but light winds across the interior should promote further stratus development through sunrise. Stratus should dissipate rather quickly after sunrise with lingering clouds possible at the immediate coast, while a moderate onshore breeze develops in the afternoon and evening. Tonight, expect more robust stratus development, especially across the interior, heading into Monday morning as the marine layer deepens.
Vicinity of SFO, Moderate confidence for momentary stratus development over the terminal through the morning hours, although breezy surface winds may provide enough disruption to stratus formation processes to keep the terminal VFR through the nighttime hours. Moderate west winds with strong gusts will develop in the afternoon and evening hours, gradually diminishing with MVFR stratus expected to develop overnight and persist through Monday morning past the end of the TAF period.
SFO Bridge Approach, Lower confidence for stratus development along the approach path through the morning. Otherwise similar to SFO.
Monterey Bay Terminals, Patches of MVFR stratus are close to or over the terminals and are expected to persist through the next few hours before retreating to the immediate coast after sunrise. A gentle to moderate onshore breeze will develop in the afternoon and evening hours. Stratus should return to the terminals early tonight through Monday morning.
(today through Friday) Issued at 432 AM PDT Sun Aug 30 2026
Fresh northwest breezes with strong to near gale force gusts steadily diminish to gentle breezes by Monday. A long period southerly swell around 15 to 17 seconds persists today. Wind driven rough seas gradually subside back to moderate by Monday through the middle of the week.
Ca, None. PZ, Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory until 9 PM PDT this evening for Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt Reyes 10-60 NM.
