Marine Weather and Tide Forecast for Pacheco, CA

SHORT TERM
Issued at 225 AM PDT Thu Mar 12 2026 (Today through Saturday)

Temperatures around 15 degrees above normal are expected today as the region is on the eastern periphery of upper-level shortwave ridging across the Eastern Pacific Ocean. Fortunately the location of the ridge will maintain onshore flow which will keep things comfortable at night and temperatures from running away. The only record high in jeopardy today is SJC with a maximum temperature forecast of 81 degrees which would tie the record from 2007. A passing upper-level shortwave trough to the north will tamp down the ridge and reinforce onshore flow, pressing pause on the warming trend Friday into Saturday. Of most impact in the short term will be minor HeatRisk. To mitigate your risk: increase hydration with water, reduce time spent outdoors or stay in the shade when the sun is strongest, and open windows at night and use fans to bring cooler air inside buildings. With roughly 50% of our population not having air conditioning, it is going to be essential that all preparations are taken to keep places of residence as temperature controlled as possible. Examples include turning your blinds upwards and closing them during the day, ensuring ceiling fan direction is counterclockwise, and keeping windows open at night to take advantage of the natural air conditioning that is onshore flow.

LONG TERM
Issued at 225 AM PDT Thu Mar 12 2026 (Sunday through Wednesday)

Global ensemble clusters are in agreement that an anomalously high amplitude upper-level longwave ridge will begin to move into the region from the Eastern Pacific Ocean Sunday. As the aforementioned ridge encroaches our area, winds will veer to become northerly which will further warm and dry the region as the sea breeze circulation is turned off. The axis of the ridge is expected to be overhead on Tuesday, which will yield the hottest day of the forecast period, before slowly drifting into the Colorado River Valley. While beyond the official seven day forecast, there is uncertainty in the evolution of the ridge. Even with the uncertainty, global ensemble clusters illustrate that it is likely that we will be dealing with anomalously high heights through Friday of next week. We will be in record breaking territory Sunday through Wednesday not only for daily records, but monthly records too. Forecast record breaking 850 mb temperatures and 500 mb heights are leading to a 50% probability that SJC reaches 90 degrees - this would be the first time ever in the month of March. It goes without saying that this is going to be the hottest that we have been this calendar year. Impacts wise, widespread minor HeatRisk on Saturday will give way to areas of moderate HeatRisk Sunday through Wednesday. To mitigate your risk: reduce time in the sun during the warmest part of the day, stay hydrated with water, stay in a cool place during the heat of the day, move outdoor activities to cooler times of the day, and for those without a/c, use fans to keep air moving and open windows at night.

AVIATION
(06Z TAFS)
Issued at 955 PM PDT Wed Mar 11 2026

VFR through Thursday evening. Gentle northwest winds will become light and variable overnight before moderate onshore flow resumes Thursday afternoon. Towards and beyond the end of the 24-hour TAF period, monitoring the potential for a shallow marine layer to form late Thursday night into Friday morning. Stratus impacts could develop at the immediate coast, but the highest chance for stratus development lies early Friday morning, after the end of the 24-hour TAF period. There is also chance for stratus impacts to OAK and SJC, but confidence is not high enough to put ceilings in the TAFs at this time.

Vicinity of SFO... VFR through at least Thursday evening. Breezy northeast winds will become light after midnight before breezy onshore flow returns Thursday afternoon into the evening, possibly well into the overnight period. Towards the end of the TAF period, monitoring the potential for a shallow marine layer to form late Thursday night into Friday morning, with a low confidence for stratus impacts at the terminal.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR through Thursday evening. Light winds will persist through Thursday morning, with onshore flow returning during the afternoon. Monitoring the potential for a shallow marine layer to form late Thursday night into Friday morning. High resolution models are hinting at potential stratus impacts at MRY, but the timeframe of highest confidence lies beyond the TAF period.

MARINE
(Tonight through next Tuesday)
Issued at 807 PM PDT Wed Mar 11 2026

Moderate to strong north breezes across the outer waters continue to cause rough seas. These winds last through the weekend with some of the inner waters being affected over the weekend itself.
Winds and seas ease into the next work week.

CLIMATE
Issued at 1140 PM PDT Tue Mar 10 2026

The following are the record high temperatures at the long term sites for March 12th, 15th, 16th and 17th.

Location Mar 12 Mar 15 Mar 16 Mar 17

Santa Rosa 83 in 2007 88 in 2004 91 in 2004 87 in 1996 San Rafael 81 in 2007 83 in 1972 87 in 1972 84 in 1972 Kentfield 83 in 2005 85 in 2004 86 in 2004 87 in 1914 Napa 86 in 2005 86 in 2004 88 in 2004 92 in 1914 Richmond 81 in 2005 85 in 2004 84 in 1972 83 in 2004 Livermore 84 in 1916 83 in 1972 88 in 1972 87 in 1972 San Francisco 79 in 2007 82 in 2004 85 in 1914 85 in 1914 SFO Airport 77 in 2007 81 in 2004 82 in 2004 82 in 2004 Redwood City 83 in 2005 84 in 2004 84 in 2004 85 in 2004 Half Moon Bay 75 in 2014 74 in 1974 78 in 1972 83 in 2004 Oakland Museum 80 in 2007 85 in 2004 85 in 2004 85 in 2004 San Jose 81 in 2007 82 in 2004 85 in 1914 88 in 1914 Salinas Airport 83 in 2007 83 in 1972 87 in 2004 87 in 2004

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.