Swell Matrix

Area Forecast Discussion

National Weather Service San Francisco CA

454 pm PDT Sat jul 4 2026

Short Term

, Issued at 1208 PM PDT Sat Jul 4 2026 (This evening through Sunday night)

Typical marine stratus is retreating to the coast early this afternoon with mostly sunny conditions across the interior for Independence Day. However, high clouds are streaming in from the southwest as a weak shortwave trough approaches the region. More on this later.

Today's forecast temperatures look to be near or slightly below seasonal averages. Maximum afternoon temperatures are forecast to be in the upper 50s to lower 60s near the immediate coastline, middle 60s to upper 70s just inland from the coast/bays, and 80s to lower 90s across the inland valleys. Breezy onshore flow is forecast to return this afternoon with wind gusts approaching 20 to 25 mph through the gaps, passes, and Salinas Valley. From the previous forecaster: "People planning to celebrate America's 250th birthday with fireworks or outdoor cookouts should remember their fire safety, obey any local burn bans, and keep a fire extinguisher nearby when playing with fireworks or cooking with open flames."

Stratus is likely to return late this afternoon near the coast, spreading through the Golden Gate into the evening (if they manage to clear out at all this afternoon), and into the inland valleys overnight and into early Sunday morning. Moisture associated with the aforementioned shortwave trough will continue to advect across the region overnight and into Sunday morning as the feature moves inland. Thus, there is generally less than a 15% chance of high- based convection across the region with less than 5% probability of thunderstorms from midnight through about 12 p.m. Sunday. However, the missing ingredient appears to be a lifting mechanism as Most Unstable CAPE remains less than 100 J/kg based off of convection- allowing models (CAMs). We will continue to monitor this closely and update the forecast accordingly. Tomorrow will feature cooler temperatures thanks to the high clouds moving across the region and look to be 5-15 degrees (especially across the interior valleys)

Long Term

..issued at 1208 PM PDT Sat Jul 4 2026 (Monday through next Friday)

The shortwave feature will be exiting the region by Monday with dry conditions and a gradual warming trend to resume throughout midweek. This will be as high pressure strengthens over the Desert Southwest with temperatures expected to be the warmest Wednesday and Thursday. We are expected afternoon temperature to range from the lower to middle 60s at the immediate coast (thanks to continued marine influences), upper 70s to middle 80s just inland away from the coast/bays, upper 80s to lower 90s in the inland valleys, and up to 105 within the warmest spots of southern Monterey County. Weak troughing returns toward the later half of the week cooling temperatures ever so slightly.

Aviation

(00z TAFS) Issued at 436 PM PDT Sat Jul 4 2026

Most terminals remain VFR as of the 00Z update with clouds persisting in KHAF. SCT-BKN high clouds near 20k ft and diurnal winds expected through the TAF period. MVFR/IFR cigs & vis for many return this evening; scattering occurs again by mid morning on Sunday.

Vicinity of SFO, SCT-BKN high clouds through the period with breezy onshore winds this afternoon near 20 kts at times. MVFR (locally IFR) cigs 07-18z with moderate confidence in cig timing.

SFO Bridge Approach, Similar to SFO.

Monterey Bay Terminals, SCT-BKN high clouds through the period with breezy onshore winds this afternoon near 20 kts at times. IFR (locally LIFR) cigs return near or after 02z Sun, clearing is expected again Sunday morning with moderate confidence in timing.

Marine

(tonight through next Thursday) Issued at 224 PM PDT Sat Jul 4 2026

Northerly flow will remain over the coastal waters over the weekend. Locally hazardous conditions will persist over the outer waters north of Point Reyes through early Sunday due to fresh to strong breezes. Calmer winds are expected later on Sunday and into Monday. A better chance for small craft winds will occur for many areas by Monday night into much of next week with building seas.

Watches, Warnings, Advisories

Ca, None. PZ, Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt Reyes 10-60 NM.

Visit this site often? Consider supporting us with a $10 contribution.
Learn more