Swell Matrix

Area Forecast Discussion

National Weather Service San Francisco CA

942 pm PDT Tue Jun 9 2026

Update

Issued at 750 PM PDT Tue Jun 9 2026

A Beach Hazards Statement has been issued for the Pacific Coast of the North Bay, San Mateo, and Santa Cruz counties as long period south swell has been creating an increased risk of sneaker waves and strong rip currents through Thursday morning. More details will be available in the BEACHES section. Otherwise, skies remain clear and the forecast remains on track.

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Short Term

, Issued at 335 PM PDT Tue Jun 9 2026 (This evening through Wednesday)

The pattern change continues as a front worked its way through the region earlier this morning. Behind it, drier air filled in clearing the clouds and leading sunny skies and a warm afternoon. High temperatures appear to be on track, with interior valley locations making it into the upper 70s to mid 80s while coastal and some Bay shoreline communities made it into the upper 50s to the mid 70s. Dry air will continue to nestle in, which should keep skies clear tonight. Low temperatures will generally be in the 50s for most sites, though temps in the 60s will be possible for areas at or above the thermal belt.

Tomorrow, Wednesday, the warming trend really kicks off. High pressure builds to the west of us, while upper level troughing moves east. Drier air and northerly winds will help usher in warmer air to the region. Many interior locations, both for mountains and interior valleys for the Bay Area and the Central Coast have a Moderate threat for HeatRisk. What does that mean? This type of heat affects those who are sensitive to heat, especially those without cooling and hydration, and some health and industries. In terms of high temperatures, they will vary from the mid 70s to the mid 80s around the Bay Shoreline, the upper 80s to mid 90s for interior valleys and mountains, and the low 60s to mid 70s for the coastal communities.

Wednesday night into Thursday morning, there will be some reprieve from the heat, as valley locations and areas beneath the thermal belt drop into upper 50s to low 60s. For those in the thermal belt, overnight lows will be warmer and in span the low 60s to upper 70s. This is also when the offshore flow / north to northeast winds pick up, particularly across the interior North Bay Mountains and the East Bay Hills. Peak wind gusts up to 45 mph can be expected and ridge top wind gusts may exceed 60 mph. Winds will be strongest overnight and then begin to ease around sunrise. These hot, dry, and windy conditions combined with mixed vegetation, such as drying or dead grass, will lead to near critical to critical fire weather conditions. A Red Flag Warning has been issued for these areas starting late Wednesday night and continuing into Thursday morning.

Long Term

..issued at 335 PM PDT Tue Jun 9 2026 (Wednesday night through next Monday)

The pattern holds on Thursday, which will lead to our warmest day of the week. Many locations will experience Moderate HeatRisk across the Bay Area and the interior Central Coast. High temperatures will vary from the low 80s to the mid 90s around the Bay Shoreline, the upper 80s to the low 100s for interior valleys and mountains, and the low 60s to low 80s for the coastal communities. With that being said, a Heat Advisory will go into effect on Thursday from 12pm- 11pm: the Bay Shoreline, North Bay Interior Mountains and Valleys, and the Santa Clara Valley and Eastern Hills.

Starting on Friday, the NBM begins a gradual cool down across the region. This will have to be something we watch closely as there is no defining synoptic feature that changes the pattern. Meaning we could see another day of warmer temperatures. Some models try to bring a marine influence back into the region, but that may struggle depending on the strength of the high. Opted to trend a few degrees warmer on Friday, given the current model diagnosis but should we see marine influence, the NBM may be on to something. Saturday, an upper level shortwave tries to form over the northern part of the state. This may bring another burst of northerlies depending on the placement or usher in onshore flow. Opted to generally keep the gradual decrease / moderation of temperatures for the weekend and into early next week.

Aviation

(06z TAFS) Issued at 936 PM PDT Tue Jun 9 2026

Widespread VFR through the TAF period. Winds are reducing across the region and look to become light overnight. A dry airmass is building into the area and will prevent chances for cloud cover and fog formation. Expect light winds to last into the late morning and early afternoon before becoming more moderate westerly winds arrive. These winds will reduce into Wednesday night. However, winds aloft over the North Bay sites look to increase into the night and turn more northerly, leading to LLWS concerns through much of that night.

Vicinity of SFO, VFR through the TAF period. Winds have reduced through the late evening, and will reduce further into the night, becoming light by the mid morning. Moderate winds return Wednesday afternoon but ease again that night.

SFO Bridge Approach, Similar to SFO.

Monterey Bay Terminals, VFR through the TAF period. Expect light winds into the night and through much of the morning. SNS sees winds increase into the mid morning while winds stay light at MRY. Breezy northwest winds return in the mid afternoon. Expect light winds to return into that night, with spotty low clouds in the Monterey Bay, but not over the terminals.

Marine

(tonight through next Monday) Issued at 936 PM PDT Tue Jun 9 2026

Gale force gusts are spreading across the northern waters, with gusty northwest winds continuing across the rest of the waters, resulting in hazardous conditions for small craft. Winds and seas begin to ease by Thursday evening and are expected to stay light through the remainder of the forecast period.

Beaches

Issued at 750 PM PDT Tue Jun 9 2026

Long period southerly swell is moving through the waters with buoy observations suggesting that a swell of around 4 to 6 feet is coming from 190 degrees, just west of due south, with a period of around 19 to 21 seconds. The long period swell will result in an increased risk of sneaker waves and strong rip currents along south and southwest facing beaches. As a result, a Beach Hazards Statement has been issued for the Pacific Coast of the North Bay, San Mateo, and Santa Cruz counties through 5 AM on Thursday. Sneaker waves will run up the beach much farther than other waves, potentially catching beachgoers by surprise and resulting in people being swept into the water. Rip currents are strong enough to pull the strongest swimmers away from shore. Swim near a lifeguard if possible. Stay back from the beach, and away from jetties, piers, beachside rocks, and other infrastructure near the water. Never turn your back to the ocean!

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Watches, Warnings, Advisories

Ca, Heat Advisory from noon to 11 PM PDT Thursday for CAZ503-504-506- 508-510-513>515.

Red Flag Warning from 11 PM Wednesday to 9 AM PDT Thursday for CAZ504-515.

Beach Hazards Statement through late Wednesday night for CAZ505- 509-529.

PZ, Small Craft Advisory from 9 AM to 9 PM PDT Wednesday for Mry Bay.

Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt Reyes 0-10 nm.

Gale Warning from 9 AM to 9 PM PDT Wednesday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 9 PM PDT Wednesday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

Small Craft Advisory until 3 AM PDT Thursday for Pt Pinos to Pt Piedras Blancas 0-10 nm.

Gale Warning until 3 PM PDT Thursday for Pt Arena to Pt Reyes 10- 60 NM.

Small Craft Advisory until 9 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM.

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