, Issued at 132 AM PST Tue Dec 9 2025 (Today and tonight)
Another round of morning clouds and patchy fog across the Bay Area. The coverage is less than yesterday and these clouds will clear in the afternoon as temperature climbs a few degrees warmer than recent days. The prolonged ridging pattern continues with the amplitude notching up over the next few days. The Eastern Pacific high now extends a ridge across northern California, and there is even a somewhat uncommon cut off high way up at 250 mb directly over the Bay Area. This is the jet stream altitude where the average wind speed this time of year is around 60 knots. We'll be lucky to break 10 knots on the 12Z sounding. This vertically stacked dome of high pressure is leading to widespread subsidence, calm winds, stagnant surface air, and warmer than normal temperatures.
..issued at 132 AM PST Tue Dec 9 2025 (Wednesday through Monday)
While the ridge has been the main scapegoat for the ongoing Tule Fog, the increasing ridge intensity will compress this cool moist layer closer to the surface and limit it's horizontal spread to the Central Valley and colder interior valleys across the Bay Area. Air quality may also suffer as a result. The 850 mb temperature will climb to around 17C by Wednesday, and park there until Friday. That's around 10C warmer than normal, close to the average for June. Surface temperatures will respond and warm up to 10F above normal, pushing some clear areas of the Bay Area and Central Coast to the mid 70s. This heat will peak on Thursday with noticeable cooling by the weekend. Despite the warm afternoons, the dry atmosphere (PW 0.3- 0.5") and long December nights will still bring morning temperatures into the 40s. The ridge axis will finally move through this weekend, allowing the pattern to become more zonal. This opens the door for some rain next week. While zonal flow doesn't support strong storms or atmospheric rivers, it looks likely that we'll at least end the dry streak sometime next week, possibly as early as Monday.
(12z TAFS) Issued at 349 AM PST Tue Dec 9 2025
Higher confidence in clearing out of the fog and stratus today for North Bay terminals. Day-to-day change gradually improving as high pressure builds aloft. Patchy stratus invof SF Bay providing lower confidence there, but based on persistence forecast KOAK likely to remain VFR.
Vicinity of SFO, Patch of stratus and fog moving along the peninsula likely to persist through sunrise, clearing to VFR in the few hours following. Lower chance of stratus overnight into Wednesday morning compared to this morning. Medium confidence in cigs holding off until just before sunrise Wednesday.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, High confidence in VFR through the TAF period. Light drainage offshore winds overnight with light onshore flow during the afternoons.
(today through Sunday) Issued at 349 AM PST Tue Dec 9 2025
Northwest winds increase to a strong breeze today into mid week across the outer waters. Gentle breeze persists across the inner coastal waters. A new, long period northwesterly swell is expected by midday Wednesday, lasting into the early weekend.
Issued at 132 AM PST Tue Dec 9 2025
Long period swell will impact the coast Wednesday - Friday. This energy brings strong rip currents, an increased risk for sneaker waves, and large breaking waves. NW swell around 8 feet with a 15 second period will translate to breaking waves up to 15-20 feet. These conditions may warrant a Beach Hazards Statement, particularly with the warm weather likely luring more people to the Beach.
Ca, Beach Hazards Statement from Wednesday morning through Friday evening for CAZ006-505-509-529-530.
PZ, Small Craft Advisory until 9 PM PST this evening for Pt Pinos to Pt Piedras Blancas 0-10 nm.
