Marine Weather and Tide Forecast for Union City, CA

SHORT TERM
Issued at 113 PM PDT Sun Jun 7 2026 (This evening through Monday)

Upper level troughing continues across the region, bringing below normal temperatures to the region. High temperatures today will be in the mid 70s to low 80s across the interior and in the 50s to low 60s along the coast. Temperatures trend slightly cooler tomorrow with highs in the 70s across the interior and 50s to low 60s along the coast. Gusty onshore winds are expected along the coastline and across the higher elevations this afternoon and evening. Gusts are expected to peak between 25 to 35 mph with locally stronger gusts possible across the higher terrain. Not anticipating winds to be as strong as they were yesterday given the weaker SFO-WMC and WFO-ACV gradients. For context, the SFO-WMC gradient peaked around +10mb yesterday afternoon while it is forecast to peak around +3 to +5mb today. Winds are expected to pick up again on Monday ahead of a weak cold front arriving Monday night into Tuesday morning with the SFO- WMC gradient strengthening to +11 to +12mb. Gusty, onshore winds are expected to move through the region during the day on Monday with widespread gusts between 25 to 35 mph. Favored areas (the coast, higher terrain, mountain gaps/passes) will see locally stronger gusts between 35 to 40 mph. Conditions are not expected to meet Wind Advisory criteria. Still, it would be worth securing any loose outdoor items before gustier winds move through so they don't blow away.

LONG TERM
Issued at 113 PM PDT Sun Jun 7 2026 (Monday night through next Saturday)

Troughing continues through Tuesday before the pattern changes midweek. A weak cold front will pass through Monday night into Tuesday morning and bring a chance for drizzle to far northern, coastal Sonoma County. Elsewhere, rain chances have largely backed off with no precipitation expected across the rest of the region.
Ensembles agree and have trended downwards with high agreement that only a trace of rain to potentially a few hundredths of an inch will fall. Temperatures on Tuesday will warm slightly compared to Monday with highs in the 70s to low 80s across the interior and 50s to mid 60s along the coast.

The pattern begins to change Wednesday as upper level troughing progresses eastward and strong upper level ridging/surface high pressure sets up over the eastern Pacific Ocean. High temperatures will warm to 10 to 15 degrees above normal across the interior and higher elevations while coastal locations stay seasonally warm. The current forecast has high temperatures in the upper 80s to mid 90s with the warmest locations in the North/East Bays and interior Central Coast reaching the low 100s. That said, the higher end of this forecast should be taken with some caution. Ensemble guidance shows a wide range of possible high temperatures for Wednesday and Thursday with other models keeping high temperatures in the low to mid 90s across the interior. Models will come into better agreement as we get closer in time to Wednesday/Thursday but would not be surprised if the forecasted high temperatures shift a bit. Hot weather continues into Friday but temperatures cool into the upper 80s to low 90s across the interior with warmer temperatures expected across the interior East Bay and Central Coast. The current forecast has widespread Moderate HeatRisk across the Bay Area which impacts those who do not have adequate access to cooling or drink enough water. If you are spending time outdoors, make sure to take breaks in the shade and drink plenty of water.

Fire weather concerns increase late Wednesday into Thursday as a round of gusty, northerly winds move through the North Bay. The strongest winds will be in the Sacramento Valley but will extend into the interior North Bay Mountains, primarily on the Napa County side. Daytime humidity retention is very poor with humidity values dropping as low as 8%. Overnight recoveries will not offer much relief with overnight humidity values peaking around 25-30% across the higher elevations. Fuels are expected to dry rapidly given the combo of gusty winds, hot weather, and very dry conditions which is resulting in elevated fire weather concerns. For the moment, the highest fire weather concerns are across the North Bay interior mountains with the strongest northerly gusts limited to this region.
The rest of the Bay Area and Central Coast will be hot and dry but much less windy. Remember, one less spark, one less wildfire.

AVIATION
(18Z TAFS)
Issued at 1151 AM PDT Sun Jun 7 2026

VFR everywhere through the TAF period with some passing high clouds.
Widespread moderate onshore breezes with gusts in excess of 15kts will prevail beginning this afternoon into the evening. Winds are expected to diminish overnight, but most sites will remain gusty with gentle to moderate breezes (~10-15kts).

Vicinity of SFO...VFR conditions with gusts in excess of 25kts and moderate winds (~15-20kts). OAK won't experience gusts until Monday morning and the wind will be slightly lower than SFOs. High confidence in the forecast.

SFO Bridge Approach...Similar pattern to SFO, except winds will be slightly lower (around 15kts at 20Z) and gusts in excess of 25kts are more probable. Gusty conditions will begin an hour later than SFO and will ease around 05/06Z before picking up again late Monday morning.

Monterey Bay Terminals...Onshore winds are expected to increase by the early afternoon. MRY will experience frequent gusts up to 20 kts. SNS gusts may be more infrequent through the afternoon, therefore it was not included in the TAF. Overnight, a marine layer between 1000-1500 feet may result in a brief scattered cloud deck, though confidence is currently to low to assess if it'll become MVFR. For now, VFR through the TAF period.

MARINE
(Today through Friday)
Issued at 935 AM PDT Sun Jun 7 2026

Moderate northwesterly winds and seas will continue through today then gradually ease tonight into Monday before building once again midweek.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Monday for Mry Bay.

Gale Warning until 9 PM PDT this evening for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 3 PM PDT Monday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.