Marine Weather and Tide Forecast for East Palo Alto, CA

UPDATE
Issued at 917 AM PDT Sat Apr 19 2025

The marine layer came in a little deeper overnight than originally forecast with stratus blanketing the coast and filtering into the interior valleys. Stratus coverage is a little less widespread across the elevated terrain than it has been for the past few days.
This is reflected in the 24 hour temperature change which shows spots across the higher elevations are generally 5 to 10 degrees warmer than they were yesterday due to the lack of cloud cover.
Comparatively, the interior valleys and coastal areas, areas where stratus persists, are running up to 5 degrees cooler than they were at this time yesterday. High temperatures today are forecast to be in the upper 60s to low 70s across the interior and upper 50s to mid 60s along the coast. However, this is dependent as to how fast stratus is able to clear out this morning with prolonged stratus coverage the past few mornings keeping high temperatures cooler than originally forecast.

SHORT TERM
(Today and tonight)
Issued at 1201 AM PDT Sat Apr 19 2025

The marine layer has compressed to around 500 feet, and the low stratus is confined mostly to the Bay Area coast. The marine layer is a little deeper across the central coast, where the stratus is filling the Salinas Valley. These clouds will clear in the afternoon and the temperatures will be near normal, similar to yesterday. A weak disturbance will arrive this evening, allowing the marine layer to deepen. As a result, cloud cover will be more extensive early Sunday morning. The offshore winds will also weaken as the gradient relaxes. This will allow more low-level moisture, and there could be patchy fog and even some drizzle across the region.

LONG TERM
(Sunday through Friday)
Issued at 1201 AM PDT Sat Apr 19 2025

The disturbance will quickly move through Sunday, allowing persistent zonal flow to become entrenched from Sunday afternoon through Tuesday. This will bring fair weather with mostly clear skies, gentle to moderate onshore winds, and high temperatures above seasonal normal. The typical warmer inland areas have a roughly even chance of breaking 80 degrees Monday. This warmer weather will cause minor HeatRisk, which can be hazardous to those extremely sensitive to the heat. Otherwise, this period will be pretty nice.

Ensembles are now in good agreement that the pattern will change mid week as a deep trough disrupts the subtropical high in the eastern Pacific. This system will bring a cooler air mass from the NW, causing surface temperatures to cool back below normal by Friday. The strength and timing of this trough is still uncertain, but it is looking more likely that some light rain will fall Friday-Saturday.

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
(Today through Thursday)
Issued at 1054 AM 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 AM PDT Monday for Pt Arena to Pt Reyes 10-60 NM.

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