Marine Weather and Tide Forecast for Berkeley, CA

SHORT TERM
(This evening through Sunday)
Issued at 127 PM PDT Sat Apr 19 2025

Stratus is dissipating across the interior but persists along the coastline. The exception to this is interior Sonoma County where a circulation just offshore continues to feed stratus into the Sonoma Valley. Nudged high temperatures along the coast down by 2-3 degrees to account for continued stratus coverage along the coast with highs forecast to reach the upper 50s to low 60s. Across the interior, clearing skies will allow for increased radiational warming with highs to reach the upper 60s to mid 70s. Some uncertainty remains about high temperatures across the Sonoma Valley, if stratus coverage is able to dissipate within the next few hours then high temperatures are likely to reach the low 70s. If stratus coverage persists into the mid to late afternoon, high temperatures will struggle to reach the upper 60s. We'll keep an eye on satellite and evaluate if any changes need to be made for today's forecast across the North Bay. Light, onshore winds will persist through the remainder of the weekend with locally breezier conditions across the elevated terrain. A weak shortwave trough will move through the region this evening into Sunday. This disturbance will allow the marine layer to deepen to around 2000ft and bring widespread overcast conditions to the Bay Area and Central Coast. High temperatures on Sunday are forecast to be in the low to mid 70s across the interior and upper 50s to mid 60s along the coastline.
The main question for tomorrow's forecast is how long stratus coverage will persist and what impact that will have on the high temperatures. We may expect to see a similar setup to today, where areas that have prolonged stratus coverage may struggle to reach their forecast highs vs areas that clear faster will reach their forecast highs more easily.

LONG TERM
(Sunday night through next Friday)
Issued at 127 PM PDT Sat Apr 19 2025

By Sunday evening, the weak upper level disturbance will have exited the region with high pressure and zonal upper level flow replacing it. High resolution guidance shows the marine layer compressing to around 500 ft starting Sunday night and remaining compressed through Tuesday. The combination of a compressed marine layer, zonal flow, and high pressure will result in rising temperatures Monday and Tuesday. Temperatures across the interior will be about 5 to 10 degrees above normal in the mid to upper 70s with a few areas possibly reaching the low 80s. Along the coast temperatures will be cooler, more seasonal, with highs in the low to mid 60s expected.
Minor HeatRisk persists Monday and Tuesday for portions of the Bay Area and Central Coast but this will primarily only impact individuals who are incredibly sensitive to heat.

The pattern shifts Wednesday with interior temperatures going from above normal to below normal as zonal upper level flow gives way to upper level troughing. A weaker upper level trough will arrive Wednesday, giving way to weak ridging on Thursday, before a deeper upper level trough arrives Friday. This second trough (Friday into the weekend) will be associated with a surface low pressure system and a cold front moving through the region. Temperatures will cool to the mid to upper 60s across the interior and to the upper 50s to low 60s along the coast starting Wednesday. Cooler temperatures will persist through the end of the forecast period with CPC guidance highlighting below normal temperatures continuing through the end of April. We are still monitoring potential for light rain towards the end of the forecast period (Friday into the weekend) with ensemble guidance indicating some potential for light rain. However, there is still a fair amount of uncertainty regarding how deep upper level troughing will be and how far south rain will spread. For example, the previous forecast update showed more widespread light rain across the Bay Area and Central Coast while this afternoon's limited it to the North Bay. It is likely we will see some light rain from this system but it is still too far out for exact locations and forecast amounts. Initial NBM guidance suggests some potential for breezier conditions next weekend as this system moves through the region. Guidance is likely to continue fluctuating in the short term with forecast confidence increasing as we get closer to the end of next week.

AVIATION
(18Z TAFS)
Issued at 1133 AM PDT Sat Apr 19 2025

Stratus clouds /MVFR-IFR/ are steadily eroding inland under diurnal surface warming and mixing, while stratus continues closest to the coastline. The marine layer depth was 1600 feet on the morning 12z Oakland upper sounding, while recent profiler data at Fort Ord and Point Sur show the marine layer depth along the north Central Coast has deepened to 2500 feet. Weak cyclonic surface winds prevail over the coastal waters with pressure gradients SFO-SAC 1.2 mb, STS-UKI 1.9 mb and SNS-SJC 1.7 mb supportive of onshore winds. The highest probability of VFR will be during the afternoon coinciding with maximum diurnal warming and mixing. For tonight and Sunday an approaching cool front and onshore winds will usher stratus /MVFR-IFR/ inland early and likely farther inland Sunday morning (compared to this morning) based on recent HRRR and HRRR output.

Vicinity of SFO...VFR is forecast for the remainder of the morning and through the afternoon. Stratus continues to mix out per recent satellite imagery. The OAK-SFO pressure gradient is currently 0.3 mb supporting temporary light northeast wind until 20z this afternoon. A west wind will resume with gusts near 20 knots during the afternoon and early evening. Stratus clouds will likely remain on the doorstep just west of the peninsula, with a return of stratus /MVFR/ 03z this evening. MVFR in stratus tonight and Sunday morning with mix out time forecast 1930z.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Southerly to westerly winds from the inner coastal waters to the Monterey Bay continue to advect stratus /MVFR-IFR/ inland while erosion of stratus continues along the inland edges of the stratus. It'll take up to another couple hours for the stratus to erode to VFR at the nearby airport terminals.
Best probability for VFR is during the afternoon, then stratus /MVFR-IFR/ returns early evening and remaining for tonight and Sunday morning. Winds mainly onshore 5 to 12 knots.

MARINE
(Tonight through next Thursday)
Issued at 127 PM PDT Sat Apr 19 2025

Breezy to gusty winds increase through the day specifically over the northern outer waters, as a weak cold front approaches from the north. The increasing winds will result in a building northerly fresh swell. Gusty winds spread across the waters into the next work week and look to remain through the week.

MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory from 3 PM Sunday to 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 3 PM PDT Monday for Pt Arena to Pt Reyes 10-60 NM.

Small Craft Advisory from 9 AM Sunday to 3 PM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM.