Marine Weather and Tide Forecast for San Leandro, CA

SHORT TERM
Issued at 1229 PM PDT Fri May 15 2026 (This evening through Monday)

Skies are generally clear across the Bay Area and Central Coast as the fringes of an upper level ridge continue to impact the region.
Any stratus formation tonight should be limited in extent, possibly confined to favored valley or mountaintop locations. High temperatures today range from the upper 70s to the upper 80s inland, the upper 60s to upper 70s along the bays and the upper 50s to middle 60s along the Pacific coast. Highs through the weekend will dip into the 70s to the lower 80s inland, and the upper 60s to middle 70s near the Bays.

The upper level pattern features a trough axis moving parallel to the coast of British Columbia and a ridge stalled out over the eastern Pacific. As that trough axis moves into the Pacific Northwest through the day, the pressure gradient should increase and lead to a strengthening of the wind gusts across the region. Wind gusts will reach 35 to 45 mph today along the coast, through gaps and passes, and across the ridgelines today, while gusts of 20 to 30 miles per hour are expected to develop elsewhere. Notably, unlike the traditional diurnal wind patterns, winds will not diminish overnight across the coast and at the higher elevations. Indeed, at the higher elevations, the strongest winds may occur during the nighttime as a decoupled atmosphere exposes these areas to strong jets aloft.

Saturday and Sunday look to be the peak of this wind event as the upper level trough continues to crawl into the northern Rockies through Sunday, further tightening the pressure gradient across the state, before dropping into the Great Basin on Sunday and setting off the inside slider pattern. This is also the time that a strong jet develops at and just off the coast south of Cape Mendocino and especially to the south of Point Arena. Wind gusts along the coastal regions inch up to around the 40 to 45 mph (locally up to 50 mph)
range, with gusts around 35 to 45 mph through the San Bruno gap and the northern Salinas Valley, and 25 to 35 mph elsewhere. Winds will peak Sunday night into Monday morning for the interior mountains of the North and East Bay down into parts of the Santa Cruz Mountains, as a jet of downsloping air comes down from the Klamath Mountains and the northern Sierra Nevada and through the Sacramento Valley.
Gusts of 40 to 45 mph, locally up to 50 mph, are expected along the ridgelines.

With the potential mixing down of the intense winds aloft down to the surface I've considered issuing a Wind Advisory for the immediate coast on Saturday. The latest guidance from the NAM suggests a couple of timeframes, one on Saturday morning and another Saturday evening into the overnight period, when 925 mb winds (that is, winds around 2,500 ft above sea level) reach 40 to 55 knots across the coastal regions. Should these winds mix down to the surface, the coastal regions will reach Wind Advisory criteria easily. The main source of uncertainty then is whether the winds will mix down to the surface, and high resolution models are showing some signs that it's possible at favored coastal locations -- think Point Reyes, or Pillar Point near Half Moon Bay. What we haven't seen is those wind gusts over a wide enough area to warrant a Wind Advisory across the coastal zones. The night shift will re-evaluate the situation and may issue a Wind Advisory if warranted.

Wind Advisory or not, the strong gusts will still result in significant impacts to those impacted by them, including loose branches, isolated downed trees resulting in potential power outages, blowing sand across beaches, and difficult driving conditions for high profile vehicles. Now is the time to bring in loose items outdoors, while the winds are still relatively calm. In addition, the strong northwest to north winds will result in large and turbulent waves across the beaches, and dry to very dry conditions in the interior which will elevate the fire weather danger through Monday. Sunday and Monday looks to be the driest days as the daytime relative humidities reach 10 to 25% across the interior and within the higher elevations of the coastal ranges. See the BEACHES and FIRE WEATHER sections for more details on these threats.

LONG TERM
Issued at 1229 PM PDT Fri May 15 2026 (Monday night through next Thursday)

By Monday afternoon, the upper level low will weaken and pull away into the northern Rockies, allowing the pressure gradient to slacken and a developing upper level ridge over the eastern Pacific to begin influencing the weather pattern. With California sitting between the building ridge and the lingering trough, high temperatures across the region are still a little uncertain. Continuing to see the NBM output run a little warm for the next work week, so after collaboration with our neighbors and national centers, the high temperature forecast was tamped down by as much as 3 to 5 degrees, especially along the coastal and valley regions. The general pattern will be for highs in the 80s to the lower 90s inland, the middle 70s to the middle 80s near the bays, and the 60s to lower 70s along the Pacific coast.

AVIATION
(18Z TAFS)
Issued at 1025 AM PDT Fri May 15 2026

Currently VFR at all terminals with the exception of some mist and haze being observed at HAF and SNS respectively. High confidence in VFR through the TAF period; however, haze will reduce slant range visibilities. Winds will strengthen through the morning, becoming strong and gusty this afternoon and evening with widespread gusts of 25 to 35 knots expected.

Vicinity of SFO...Currently VFR with northwesterly flow. High confidence in VFR through the TAF period. Winds will continue to back and strengthen through the morning, becoming strong and gusty this afternoon. Gusts up to 30 knots are likely this afternoon and evening with isolated gusts up to 35 knots possible.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Currently VFR with northwesterly flow at MRY and MVFR with westerly flow and haze at SNS. Aside from haze, high confidence in VFR through the TAF period. Onshore winds will continue to strengthen through the morning, becoming moderate and gusty this afternoon and evening.

MARINE
(Today through Wednesday)
Issued at 1025 AM PDT Fri May 15 2026

Widespread hazardous marine conditions are expected today and through the weekend. Strong to near gale force northerly breezes will increase through the weekend to become near gale force to gale force with widespread severe gale force gusts. Isolated storm force gusts are expected along the coastal jet region of Big Sur. Rough to very rough seas will build as a result.
Conditions will slowly begin to improve Monday.

FIRE WEATHER
Issued at 511 AM PDT Fri May 15 2026

Gusty offshore winds are building and strengthen through the weekend, leading to elevated fire concerns. Peak gusts above 30 mph for most areas are expected, with around 40 to 50 mph along the coast, through gaps and passes, and across the ridgelines. Very low daytime humidities of 15-25% will prevail across the interior regions and higher peaks, with reduced overnight humidity recoveries. Strong winds persist into the early part of Monday before diminishing, but humidities will be slow to recover as a modest offshore flow continues into the work week.

BEACHES
Issued at 1229 PM PDT Fri May 15 2026

A Beach Hazards Statement will go into effect for west facing beaches along the Pacific Coast from 3 PM today through 9 AM Monday due to strong winds over the marine environment leading to hazardously strong wind waves and overall rough seas. Dangerous swimming, boating, and surfing conditions can be expected. Large breaking waves can overpower swimmers resulting in significant physical injury and increase the risk of drowning. Gusts will stay strong along the immediate coast, causing blowing and drifting sand and increased sea spray. Water rescue attempts may be hampered by reduced visibilities from the sea spray. Remember, NEVER turn your back on the ocean.

RGass/DialH

MTR WATCHES/WARNINGS/ADVISORIES
CA...Beach Hazards Statement through Monday morning for CAZ006-505- 509-530.

Coastal Flood Advisory from 10 PM Saturday to 3 AM PDT Tuesday for CAZ506.

PZ...Small Craft Advisory until 3 AM PDT Sunday for SF Bay N of Bay Bridge.

Small Craft Advisory until 3 PM PDT this afternoon for Mry Bay.

Gale Warning until 9 PM PDT Sunday for Mry Bay.

Gale Warning until 9 PM PDT Sunday for Pigeon Pt to Pt Pinos 0- 10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0- 10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0- 10 nm.

Gale Warning until 9 AM PDT Saturday for Pt Pinos to Pt Piedras Blancas 0-10 nm.

Storm Watch from Saturday morning through Sunday evening for Pt Pinos to Pt Piedras Blancas 0-10 nm.