, Issued at 118 PM PST Tue Nov 18 2025 (This evening through Wednesday)
Upper level troughing will slowly swing through southern CA today and tomorrow, while weak upper level ridging quickly builds and then flattens. Radar thus far has shown a few showers develop over southern Monterey and San Benito counties, while elsewhere we have a mix of sunny skies and fair weather cumulus. Tonight, skies should clear and given the moisture we may see some valley fog. Tomorrow, deterministic models suggest a weak disturbance passing over head, which may bring some high clouds and perhaps a few isolated showers to the region. Otherwise quiet weather prevails until the next system approaches the PacNW. Rain chances begin to increase for the North Bay during the evening hours.
..issued at 118 PM PST Tue Nov 18 2025 (Wednesday night through next Monday)
The aforementioned upper level low will bring a round of beneficial rain late Wednesday into Thursday. Rainfall amounts continue to be around 0.25" for the North Bay counties, with perhaps slightly higher amounts in elevated terrain. Elsewhere, amounts look to anywhere from 0.1- 0.25", with lower amounts expected for interior locations. The Santa Cruz and Santa Lucia mountains may see slightly higher amounts. Once this system exits the region, ensemble and deterministic models show upper level ridging building in for the weekend. Given additional moisture from the rain, we should see some night and morning fog. The ridge will also bring temperatures up a few degrees putting most areas near or above normal.
(00z TAFS) Issued at 349 PM PST Tue Nov 18 2025
VFR conditions with moderate diurnally driven wind dominate this afternoon. Some low VFR cumulus clouds are gradually evaporating across the East and South Bay. Overnight a deep but weak marine layer will try to form, which could bring some MVFR or low VFR clouds to the terminals by Wednesday morning. Beyond the TAF period southerly winds will begin to increase as a cold front approaches from the NW Wednesday night.
Vicinity of SFO, Standard afternoon moderate onshore wind will gradually decrease through the evening. The ceiling forecast is tricky for Wednesday. There is a good chance for a weak marine layer to roll in early Wednesday morning, but there still a lot of uncertainty whether it will carry clouds or if the bases will be above or below 3,000 feet. As the day goes on cloud cover should increase, but the ceilings will also lift. High clouds and southerly winds will increase late in the TAF period as a cold front approaches.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Mostly clear skies will continue through the evening. We have another tricky forecast for Wednesday as there is a roughly even chance for MVFR ceilings or VFR skies. SNS has a better chance of higher ceilings and less cloud coverage than MRY.
(tonight through next Sunday) Issued at 349 PM PST Tue Nov 18 2025
Buoys are reporting a fresh NW breeze and rough seas. The winds will decrease and shift to a gentle southerly breeze Wednesday, allowing rough seas to subside and allowing for a brief favorable weather window across the coastal waters. Late Wednesday an approaching cold front will cause the southerly breeze to increase to moderate before increasing and flipping back to a fresh to strong NW breeze as the front passes early Thursday morning. The winds will gradually diminish through the day Thursday as a very high NW swell up to 15 feet arrives. This swell will stick around for a while, very gradually subsiding through the weekend.
Ca, None. PZ, Small Craft Advisory until 9 PM PST this evening for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory until 3 AM PST Wednesday for Pt Arena to Pt Reyes 10-60 NM.
