Issued at 954 AM PDT Thu Sep 17 2026
The marine layer is nearly 5,000 feet deep, which is about as deep as it can get before mixing out. We did see some measurable drizzle across the Bay Area this morning, but that is now tapering off. Cooler weather is in still on track this afternoon, with calmer winds than yesterday.
, Issued at 1211 AM PDT Thu Sep 17 2026 (Today and tonight)
Satellite imagery once again shows stratus hugging portions of the coast and beginning to move inland. As noted in the evening update, this isn't a classic marine layer. It has a more strato-cu vibe due to the proximity of cold upper level low near Pt Arena. Do expect stratus to eventually fill in along a majority of the coast by sunrise. The lower heights aloft have also allowed the cloud deck to deepen 2500-3000 ft per profilers and ACARs sounding. Given the nearby low,onshore flow, and deep layer drizzle remains in the forecast as well.
Outside of drizzle chances - similar to yesterday the main weather highlights for today will be below normal temperatures and gusty onshore flow. Generally speaking - max temps today will be a few warmer than yesterday, but still below seasonal averages. Highs will top out in the 60s to near 70 along the coast and 70s to mid 80s interior. Onshore gradients aren't overly impressive overnight, but still seeing some gusts 30-45 mph for the Delta and E Bay Hills. These gusty conditions will lingering through the early morning hours before easing through the afternoon/evening hours.
Thursday night: the upper low begins to lose its grip on the Bay Area as it slowly moves to the northeast. Behind the departing low shortwave ridging builds. A more classic marine layer will develop with solid stratus along the coast and inland valleys. Cannot rule out some patchy drizzle.
..issued at 107 AM PDT Thu Sep 17 2026 (Friday through Wednesday)
Friday will be a transition day as the upper low fully exits to the northeast and shortwave ridging builds overhead. Once the morning marine layer rolls back to the coast a marked warming trend will develop to kick off the weekend. 5-10 degrees of warming are expected. The warming trend will continue through Saturday with temperatures reaching above normal by Saturday. A few low 90s will return Saturday afternoon across the interior Central Coast. Temperatures will also get a boost on Saturday with a few bursts of offshore flow. Nothing overly strong, but a switch nonetheless. Offshore winds will be most realized over the higher terrain of the N and E Bay. The warm up will be short-lived as the ridge gets replaced by yet another upper low moving in from the west on Sunday. Marine layer will likely deepen and temperatures cool 5-10 degrees.
Monday and beyond is still on the lower end of confidence. Tonight's 00Z model suite is starting to show a roller coaster of temps next week. A slight warming up and then a slight cool down. Uncertainty on the shoulder seasons is actually pretty common. Cluster analysis doesn't provide a lot of additional clarity except that models are split. Not expecting rain per SE the uncertainty is around temperatures.
(18z TAFS) Issued at 1046 AM PDT Thu Sep 17 2026
Low clouds will gradually scatter out into the early afternoon hours, giving way to VFR conditions across area terminals. Light winds will increase this afternoon with a moderate onshore breeze developing. The marine layer is anticipated to return this evening. Latest models indicate the marine layer will compress overnight resulting in lower cigs overnight into Friday. Confidence is moderate with respect to timing and cig heights.
Vicinity of SFO, VFR cigs will gradually scatter out by the afternoon, with a moderate onshore breeze developing in the afternoon. Cigs will return this evening and persist through the overnight hours, with moderate confidence in timing and ceilings height.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR cigs will scatter out by early afternoon with a gentle west-northwest wind developing. Winds will ease overnight becoming light and locally variable with low clouds anticipated to return. Confidence in timing is moderate.
(today through Tuesday) Issued at 911 AM PDT Thu Sep 17 2026
Gentle to light breezes persist through Friday morning with mild seas across the coastal waters. A shift occurs Friday afternoon as northwesterly winds ramp up to fresh to strong breezes. Small Craft Advisories take effect Friday afternoon for Monterey Bay and the southern coastal waters from Pigeon Point south down to Point Piedras Blancas. Winds remain enhanced through the weekend, maintaining hazardous conditions for small craft while overall seas remain light to moderate through Sunday.
Ca, None. PZ, Small Craft Advisory from 3 PM Friday to 3 AM PDT Saturday for Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm.
Small Craft Advisory from 3 PM to 9 PM PDT Friday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
