Marine Weather and Tide Forecast for Portola Valley, CA
May 2, 2024 9:26 PM PDT (04:26 UTC) Change Location
 | Sunrise 6:09 AM Sunset 8:00 PM Moonrise 2:15 AM Moonset 12:56 PM |
PZZ531 San Francisco Bay South Of The Bay Bridge- 855 Pm Pdt Thu May 2 2024
.small craft advisory in effect until 9 pm pdt this evening - .
.small craft advisory in effect from Friday afternoon through late Friday night - .
Tonight - W winds 15 to 25 knots with gusts up to 30 knots - . Diminishing to 5 to 10 knots after midnight.
Fri - W winds 15 to 20 knots with gusts up to 25 knots.
Fri night - W winds 15 to 20 knots with gusts up to 30 knots.
Sat - W winds 10 to 15 knots with gusts up to 25 knots. Rain.
Sat night - W winds 15 to 25 knots with gusts up to 30 knots.
Sun - NW winds 10 to 15 knots.
Sun night - W winds 10 to 15 knots.
Mon - W winds 10 to 15 knots.
Tue - W winds 10 to 15 knots with gusts up to 25 knots.
PZZ500 855 Pm Pdt Thu May 2 2024
Synopsis for the central california coast and bays including the Monterey bay - Greater farallones - .and cordell bank national marine sanctuaries - .
gusty winds persist throughout Friday afternoon, with gale force gusts of 35 to 45 knots possible in the southern waters. Strong winds will result in hazardous seas and steep wind waves with significant wave heights reaching 10 to 13 feet in the outer waters. Conditions briefly improve over the weekend, but will increase into next week to more moderate levels. Rain chances begin late Friday night as a trough descends over the region into Saturday.
gusty winds persist throughout Friday afternoon, with gale force gusts of 35 to 45 knots possible in the southern waters. Strong winds will result in hazardous seas and steep wind waves with significant wave heights reaching 10 to 13 feet in the outer waters. Conditions briefly improve over the weekend, but will increase into next week to more moderate levels. Rain chances begin late Friday night as a trough descends over the region into Saturday.
Area Discussion for - San Francisco/Monterey Bay Area, CA
(hide/show) HelpNOTE: mouseover dotted underlined text for definition
FXUS66 KMTR 030358 AFDMTR
Area Forecast Discussion National Weather Service San Francisco CA 858 PM PDT Thu May 2 2024
New UPDATE, MARINE
SYNOPSIS
Issued at 119 PM PDT Thu May 2 2024
Warm weather continues through the day today and tomorrow afternoon. Beneficial rain befalls the region late Friday and through the afternoon of Saturday. Cool overnight temperatures expected Sunday and Monday mornings. Dry conditions return Sunday and last through next week.
UPDATE
Issued at 858 PM PDT Thu May 2 2024
Pleasantly warm day throughout the Bay Area with temperatures primarily in the 70's and a few stations reaching the low 80's. One more day of above average temperatures before cooler, below average temperatures return heading into the weekend. Breezy to gusty westerly to northwesterly winds continue through Friday in coastal regions and elevated terrain. Gustier winds will extend farther inland heading into the weekend as a low pressure system moves inland. Precipitation forecast looks to be on track with continuing good model consensus that beneficial rainfall returns Saturday.
Overall forecast remains on track.
SHORT TERM
(This evening through Friday)
Issued at 119 PM PDT Thu May 2 2024
A look across the region at this hour shows many interior locations already reaching into the low to mid 70s. Meanwhile closer to the coast and bay shorelines, temperatures are in the upper 50s to low 60s. Temperatures will warm today into the high 70s away from the coastline, with a select few locations maybe seeing temperatures reach the 80 degree F mark. However, chances of reaching the 80 degree mark are fairly low even for the favored interior spots. Napa appears to be the most highly favored for the chance to reach 80 degrees, but even then, with only a whopping 30% chance. Elsewhere in locations such as Gilroy and Hollister, chances are only in the 20% range. Coastal locations will only see highs in the mid 60s at best.
As upper level ridging builds and continues, temperatures are expected to be largely similar tomorrow. Breezy northwesterly winds in the afternoons will continue, but ease into the nighttime.
Late Friday night, rain begins to approach the region, impacting the North Bay first, and then slowly making its way south. The previous forecaster's long term discussion still largely holds, so will not reinvent the wheel. Will just mention that rain totals have increased ever so slightly from the previous forecast, but not by much. By a few hundredths generally. Descriptions in the long term discussion still hold largely.
LONG TERM
(Friday night through next Wednesday)
Issued at 119 PM PDT Thu May 2 2024
Seeing good global and mesoscale model agreement, one long wave trough is now stationary along the West Coast, part of an unsteady northern hemispheric long wave trough pattern. A low pressure system from the Aleutian Islands will move through the long wave trough and bring rain to our forecast area Friday night and Saturday. Rain developing first over the North Bay Friday night, rain quickly spreading southeastward across much of the rest of the forecast area Saturday. Expect noticeably cooler temperatures especially inland Saturday with daytime highs in the upper 50s to mid 60s, warmest southern interior; daytime temperatures 5F to 15F below early May normals. The low is still expected to brush by and tap higher levels of water vapor extending far north of Hawaii, while retaining a strong mid-latitude influence e.g. it's an appreciably cold core system up through the 700 mb level by comparison on Oakland upper air climatology, the pool of cold air a little more compact by the 500 mb level. Unlikely there'll be layer instability extending above 700 mb, forecast 700-500 mb lapse rates are low and much more stable. Recent precipitable water values on the GFS maintain between 1.00" and 1.10" Saturday, not far from the max moving average on Oakland upper air sounding climatology in early May.
Seeing some recent increases in model forecast rainfall amounts.
For example over 0.50" to 1" rain totals North Bay, near 0.50" low elevations and up to 0.75" to 1" East Bay hills/mountains and the Santa Cruz Mountains, 0.10" to 0.20" interior north Central Coast to around 0.50" Big Sur Coast. The Bay Area and northernmost north Central Coast may receive over half if not nearly May normal precipitation from this system if current QPF verifies. As mentioned expect wet and cooler weather Saturday, gusty northwest winds over the coast temporarily subsiding with the passage of a surface cold front/trough.
Chilly to cold overnight low temperatures for the time of year (40s coastside and bayside / 30s inland) are forecast late Saturday night to Sunday morning and Sunday night to Monday morning. San Francisco and Oakland downtown possibly including a few other locations may be nearing record lows Sunday and Monday mornings. Stay tuned to updates, right now Sun-Mon mornings look to be the chilliest. Forecast temperature guidance could edge a little lower between now and late weekend.
End of previous discussion.
Overall, this weekend's system will bring beneficial, although late-season rain. Late Saturday, rain begins to cease and a dry pattern returns to the region with temperatures gradually warming through the next week into the low to mid 70s for interior regions.
Despite gradual warming, CPC 6-10 day outlooks place much of California in a below-normal temperature category, and below normal for precipitation.
AVIATION
(00Z TAFS)
Issued at 548 PM PDT Thu May 2 2024
VFR remains through the night and much of Friday for all but the immediate coast and MRY. Breezy and gusty winds continue into the early night. Winds ease into the late night becoming light to moderate. As winds reduce MVFR/IFR CIGs build along the coast and Monterey Bay. Cloud cover thins in the mid to late morning Friday.
Gusty westerly winds arrive Friday afternoon and last into the night. As winds reduce, low clouds move into the coast and bays Friday night, leading to MVFR and IFR CIGs .
Vicinity of SFO...VFR through the TAF period. Gusty northwest winds with around 35-40 kt kt gusts last into the night before dropping off. Scattered lower clouds arrive in the late night and last into mid Friday morning. Gusty west winds build into Friday afternoon, peaking around 27 kts and gusting to above 30 kts. Winds reduce into late Friday evening, but remain breezy.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR/IFR CIGS affect MRY and the immediate coast of the Monterey Bay through the mid to late morning. Breezy winds last into the late evening before reducing. Winds stay light to moderate through the night before moderate to breezy winds arrive
MARINE
(Tonight through next Wednesday)
Issued at 858 PM PDT Thu May 2 2024
Gusty winds persist throughout Friday afternoon, with gale force gusts of 35 to 45 knots possible in the southern waters. Strong winds will result in hazardous seas and steep wind waves with significant wave heights reaching 10 to 13 feet in the outer waters. Conditions briefly improve over the weekend, but will increase into next week to more moderate levels. Rain chances begin late Friday night as a trough descends over the region into Saturday.
MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 9 AM PDT Friday for Mry Bay-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 9 PM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Gale Warning until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 0- 10 nm.
Gale Warning until 3 AM PDT Saturday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
Area Forecast Discussion National Weather Service San Francisco CA 858 PM PDT Thu May 2 2024
New UPDATE, MARINE
SYNOPSIS
Issued at 119 PM PDT Thu May 2 2024
Warm weather continues through the day today and tomorrow afternoon. Beneficial rain befalls the region late Friday and through the afternoon of Saturday. Cool overnight temperatures expected Sunday and Monday mornings. Dry conditions return Sunday and last through next week.
UPDATE
Issued at 858 PM PDT Thu May 2 2024
Pleasantly warm day throughout the Bay Area with temperatures primarily in the 70's and a few stations reaching the low 80's. One more day of above average temperatures before cooler, below average temperatures return heading into the weekend. Breezy to gusty westerly to northwesterly winds continue through Friday in coastal regions and elevated terrain. Gustier winds will extend farther inland heading into the weekend as a low pressure system moves inland. Precipitation forecast looks to be on track with continuing good model consensus that beneficial rainfall returns Saturday.
Overall forecast remains on track.
SHORT TERM
(This evening through Friday)
Issued at 119 PM PDT Thu May 2 2024
A look across the region at this hour shows many interior locations already reaching into the low to mid 70s. Meanwhile closer to the coast and bay shorelines, temperatures are in the upper 50s to low 60s. Temperatures will warm today into the high 70s away from the coastline, with a select few locations maybe seeing temperatures reach the 80 degree F mark. However, chances of reaching the 80 degree mark are fairly low even for the favored interior spots. Napa appears to be the most highly favored for the chance to reach 80 degrees, but even then, with only a whopping 30% chance. Elsewhere in locations such as Gilroy and Hollister, chances are only in the 20% range. Coastal locations will only see highs in the mid 60s at best.
As upper level ridging builds and continues, temperatures are expected to be largely similar tomorrow. Breezy northwesterly winds in the afternoons will continue, but ease into the nighttime.
Late Friday night, rain begins to approach the region, impacting the North Bay first, and then slowly making its way south. The previous forecaster's long term discussion still largely holds, so will not reinvent the wheel. Will just mention that rain totals have increased ever so slightly from the previous forecast, but not by much. By a few hundredths generally. Descriptions in the long term discussion still hold largely.
LONG TERM
(Friday night through next Wednesday)
Issued at 119 PM PDT Thu May 2 2024
Seeing good global and mesoscale model agreement, one long wave trough is now stationary along the West Coast, part of an unsteady northern hemispheric long wave trough pattern. A low pressure system from the Aleutian Islands will move through the long wave trough and bring rain to our forecast area Friday night and Saturday. Rain developing first over the North Bay Friday night, rain quickly spreading southeastward across much of the rest of the forecast area Saturday. Expect noticeably cooler temperatures especially inland Saturday with daytime highs in the upper 50s to mid 60s, warmest southern interior; daytime temperatures 5F to 15F below early May normals. The low is still expected to brush by and tap higher levels of water vapor extending far north of Hawaii, while retaining a strong mid-latitude influence e.g. it's an appreciably cold core system up through the 700 mb level by comparison on Oakland upper air climatology, the pool of cold air a little more compact by the 500 mb level. Unlikely there'll be layer instability extending above 700 mb, forecast 700-500 mb lapse rates are low and much more stable. Recent precipitable water values on the GFS maintain between 1.00" and 1.10" Saturday, not far from the max moving average on Oakland upper air sounding climatology in early May.
Seeing some recent increases in model forecast rainfall amounts.
For example over 0.50" to 1" rain totals North Bay, near 0.50" low elevations and up to 0.75" to 1" East Bay hills/mountains and the Santa Cruz Mountains, 0.10" to 0.20" interior north Central Coast to around 0.50" Big Sur Coast. The Bay Area and northernmost north Central Coast may receive over half if not nearly May normal precipitation from this system if current QPF verifies. As mentioned expect wet and cooler weather Saturday, gusty northwest winds over the coast temporarily subsiding with the passage of a surface cold front/trough.
Chilly to cold overnight low temperatures for the time of year (40s coastside and bayside / 30s inland) are forecast late Saturday night to Sunday morning and Sunday night to Monday morning. San Francisco and Oakland downtown possibly including a few other locations may be nearing record lows Sunday and Monday mornings. Stay tuned to updates, right now Sun-Mon mornings look to be the chilliest. Forecast temperature guidance could edge a little lower between now and late weekend.
End of previous discussion.
Overall, this weekend's system will bring beneficial, although late-season rain. Late Saturday, rain begins to cease and a dry pattern returns to the region with temperatures gradually warming through the next week into the low to mid 70s for interior regions.
Despite gradual warming, CPC 6-10 day outlooks place much of California in a below-normal temperature category, and below normal for precipitation.
AVIATION
(00Z TAFS)
Issued at 548 PM PDT Thu May 2 2024
VFR remains through the night and much of Friday for all but the immediate coast and MRY. Breezy and gusty winds continue into the early night. Winds ease into the late night becoming light to moderate. As winds reduce MVFR/IFR CIGs build along the coast and Monterey Bay. Cloud cover thins in the mid to late morning Friday.
Gusty westerly winds arrive Friday afternoon and last into the night. As winds reduce, low clouds move into the coast and bays Friday night, leading to MVFR and IFR CIGs .
Vicinity of SFO...VFR through the TAF period. Gusty northwest winds with around 35-40 kt kt gusts last into the night before dropping off. Scattered lower clouds arrive in the late night and last into mid Friday morning. Gusty west winds build into Friday afternoon, peaking around 27 kts and gusting to above 30 kts. Winds reduce into late Friday evening, but remain breezy.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR/IFR CIGS affect MRY and the immediate coast of the Monterey Bay through the mid to late morning. Breezy winds last into the late evening before reducing. Winds stay light to moderate through the night before moderate to breezy winds arrive
MARINE
(Tonight through next Wednesday)
Issued at 858 PM PDT Thu May 2 2024
Gusty winds persist throughout Friday afternoon, with gale force gusts of 35 to 45 knots possible in the southern waters. Strong winds will result in hazardous seas and steep wind waves with significant wave heights reaching 10 to 13 feet in the outer waters. Conditions briefly improve over the weekend, but will increase into next week to more moderate levels. Rain chances begin late Friday night as a trough descends over the region into Saturday.
MTR WATCHES/WARNINGS/ADVISORIES
CA...None.
PZ...Small Craft Advisory until 9 AM PDT Friday for Mry Bay-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 9 PM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Gale Warning until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 0- 10 nm.
Gale Warning until 3 AM PDT Saturday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
toggle option: (graph/table)
Airport Reports
EDIT (hide/show) Help Click EDIT to display multiple airports. Follow links for more data.| Airport | Dist | Age | Wind kt | Vis | Sky | Weather | Temp | DewPt | RH | inHg |
| KPAO PALO ALTO,CA | 9 sm | 39 min | NW 08 | 10 sm | A Few Clouds | 57°F | 48°F | 72% | 29.98 | |
| KNUQ MOFFETT FEDERAL AFLD,CA | 10 sm | 11 min | NNW 10 | 10 sm | -- | 59°F | 50°F | 72% | 29.97 | |
| KSQL SAN CARLOS,CA | 10 sm | 11 min | NW 10G16 | 10 sm | Clear | 57°F | 50°F | 77% | 29.98 | |
| KSJC NORMAN Y MINETA SAN JOSE INTL,CA | 16 sm | 33 min | N 10 | 10 sm | A Few Clouds | 61°F | 52°F | 72% | 29.97 | |
| KHAF HALF MOON BAY,CA | 18 sm | 11 min | NNW 11G19 | 1 sm | Overcast | Mist | 52°F | 52°F | 100% | 30.00 |
| KSFO SAN FRANCISCO INTL,CA | 20 sm | 30 min | W 20G29 | 10 sm | Overcast | 55°F | 48°F | 77% | 29.96 | |
| KHWD HAYWARD EXECUTIVE,CA | 22 sm | 32 min | var 05 | 10 sm | A Few Clouds | 57°F | 52°F | 82% | 29.96 | |
| KRHV REIDHILLVIEW OF SANTA CLARA COUNTY,CA | 22 sm | 39 min | NNW 09 | 10 sm | Clear | 59°F | 50°F | 72% | 29.98 |
Palo Alto Yacht Harbor
Click for Map
Thu -- 03:14 AM PDT Moonrise
Thu -- 03:20 AM PDT 2.85 feet Low Tide
Thu -- 06:11 AM PDT Sunrise
Thu -- 08:09 AM PDT 7.33 feet High Tide
Thu -- 01:55 PM PDT Moonset
Thu -- 03:32 PM PDT -0.15 feet Low Tide
Thu -- 07:59 PM PDT Sunset
Thu -- 09:31 PM PDT 7.02 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Click for Map
Thu -- 03:14 AM PDT Moonrise
Thu -- 03:20 AM PDT 2.85 feet Low Tide
Thu -- 06:11 AM PDT Sunrise
Thu -- 08:09 AM PDT 7.33 feet High Tide
Thu -- 01:55 PM PDT Moonset
Thu -- 03:32 PM PDT -0.15 feet Low Tide
Thu -- 07:59 PM PDT Sunset
Thu -- 09:31 PM PDT 7.02 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Palo Alto Yacht Harbor, California, Tide feet
| 12 am |
| 5 |
| 1 am |
| 4.2 |
| 2 am |
| 3.4 |
| 3 am |
| 2.9 |
| 4 am |
| 3 |
| 5 am |
| 3.9 |
| 6 am |
| 5.4 |
| 7 am |
| 6.7 |
| 8 am |
| 7.3 |
| 9 am |
| 7 |
| 10 am |
| 5.9 |
| 11 am |
| 4.5 |
| 12 pm |
| 3.1 |
| 1 pm |
| 1.8 |
| 2 pm |
| 0.7 |
| 3 pm |
| -0 |
| 4 pm |
| -0 |
| 5 pm |
| 0.9 |
| 6 pm |
| 2.5 |
| 7 pm |
| 4.5 |
| 8 pm |
| 6.1 |
| 9 pm |
| 6.9 |
| 10 pm |
| 6.9 |
| 11 pm |
| 6.4 |
Tide / Current for Dumbarton Hwy Bridge, South San Francisco Bay, California Current
EDIT (hide/show) HelpDumbarton Hwy Bridge
Click for Map
Thu -- 12:08 AM PDT -0.57 knots Max Ebb
Thu -- 03:14 AM PDT Moonrise
Thu -- 03:15 AM PDT 0.00 knots Slack
Thu -- 05:59 AM PDT 0.86 knots Max Flood
Thu -- 06:11 AM PDT Sunrise
Thu -- 08:28 AM PDT -0.00 knots Slack
Thu -- 12:13 PM PDT -1.12 knots Max Ebb
Thu -- 01:55 PM PDT Moonset
Thu -- 03:39 PM PDT 0.01 knots Slack
Thu -- 07:01 PM PDT 1.67 knots Max Flood
Thu -- 07:59 PM PDT Sunset
Thu -- 10:09 PM PDT -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Click for Map
Thu -- 12:08 AM PDT -0.57 knots Max Ebb
Thu -- 03:14 AM PDT Moonrise
Thu -- 03:15 AM PDT 0.00 knots Slack
Thu -- 05:59 AM PDT 0.86 knots Max Flood
Thu -- 06:11 AM PDT Sunrise
Thu -- 08:28 AM PDT -0.00 knots Slack
Thu -- 12:13 PM PDT -1.12 knots Max Ebb
Thu -- 01:55 PM PDT Moonset
Thu -- 03:39 PM PDT 0.01 knots Slack
Thu -- 07:01 PM PDT 1.67 knots Max Flood
Thu -- 07:59 PM PDT Sunset
Thu -- 10:09 PM PDT -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Dumbarton Hwy Bridge, South San Francisco Bay, California Current, knots
| 12 am |
| -0.6 |
| 1 am |
| -0.5 |
| 2 am |
| -0.3 |
| 3 am |
| -0.1 |
| 4 am |
| 0.4 |
| 5 am |
| 0.7 |
| 6 am |
| 0.9 |
| 7 am |
| 0.7 |
| 8 am |
| 0.3 |
| 9 am |
| -0.2 |
| 10 am |
| -0.6 |
| 11 am |
| -1 |
| 12 pm |
| -1.1 |
| 1 pm |
| -1 |
| 2 pm |
| -0.7 |
| 3 pm |
| -0.3 |
| 4 pm |
| 0.3 |
| 5 pm |
| 1 |
| 6 pm |
| 1.5 |
| 7 pm |
| 1.7 |
| 8 pm |
| 1.5 |
| 9 pm |
| 1 |
| 10 pm |
| 0.1 |
| 11 pm |
| -0.4 |
San Francisco Bay Area, CA,
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