, Issued at 1201 PM PDT Sat Apr 18 2026 (This evening through Sunday)
High clouds continue to stream in from the west, yet will have very little impact on high temperatures this afternoon. We are forecasting mid 60s to lower 70s in the northwest facing locations and low-to-upper 70s elsewhere. There is a greater than 50% probability for Concord, San Jose, Gilroy, Hollister, and King City to exceed 80 degrees F on this afternoon (but less than 10% of exceeding 85 degrees F).
Tonight and into Sunday morning, expecting low clouds to return to the coast and coastal adjacent valleys as moisture increases ahead of an approaching mid/upper level low. This low will also cool temperatures slightly as clouds increase, most notability in the North Bay and San Francisco Bay Area. Meanwhile, the Central Coast will remain quite warm across the interior Sunday afternoon.
..issued at 1201 PM PDT Sat Apr 18 2026 (Sunday night through next Friday)
The progression of the anticipated cold front has slowed down by about 12-18 hours. However, we still expect pre-frontal rain showers to begin Monday morning across the North Bay and then spread southward across the Bay Area. Outside of the coastal ranges of the Central Coast, we may see very little rainfall on during the day Monday. The main cold front is now expected to move across the Bay Area and Central Coast on Tuesday morning. By Tuesday afternoon and evening, we have the greatest potential for thunderstorms with up to 30% across much of the region as up to 500 J/kg of surface based CAPE is forecast. We are mostly forecasting this rainfall to be beneficial, but urban and poorly drained areas may experience flooding concerns during periods of heavy rain showers and/or thunderstorms. The WPC has a Marginal Risk of Excessive Rainfall (at least 5%) from the Santa Cruz Mountains northward on Day 3 (5 AM Monday - 5 AM Tuesday). However, we are not expecting any major river flooding with this event.
Post-frontal rain showers and possible thunderstorms (generally less than 15%) linger into Wednesday afternoon as a colder air mass settles in behind the cold front. Drier conditions look to return to the region for the latter half of the week with troughing forecast by the clusters.
(00z TAFS) Issued at 437 PM PDT Sat Apr 18 2026
High clouds continue to build across the region ahead of a cold front over the Eastern Pacific. This front will slide very slowly towards the coast over then next couple days, keeping a steady supply of high level clouds in the TAFs. There is a chance for marine layer stratus to creep in over a few terminals tonight, but impacts should be limited to coastal terminals. The biggest question is STS, where model guidance is hinting at stratus potential Sunday morning, but the dew pint is in the low 30s and high clouds will limit nocturnal cooling, so the set-up doesn't seem right and the confidence is quite low.
Vicinity of SFO, Moderate onshore winds are gradually weakening this afternoon and that trend will continue through the evening. There is a slight (20%) chance of MVFR ceilings Sunday morning with the best chance between 12Z and 17Z.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, With higher low-level moisture, the southern terminals have the best chance for MVFR or high IRF ceilings tonight. MRY and SNS both have a 60% chance of these morning clouds before the skies clear around 18Z.
(tonight through next Thursday) Issued at 437 PM PDT Sat Apr 18 2026
Expect light winds and seas to continue through the rest of the weekend. Northerly winds shift and become southerly Sunday ahead of an incoming low pressure system and cold front. Winds will strengthen ahead of the cold front Monday through Tuesday with localized strong gusts expected. Expect moderate seas, rain and a slight chance to chance of thunderstorms Monday night and Tuesday.
Ca, None. PZ, None.
