Tuesday, September28, 2021
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Marine Weather and Tides
Castro Valley, CA

Version 3.4
NOTICE
3/30/2021 -- ANZ330 has been split into ANZ331 and ANZ332. Click EDIT in Marine Forecast and select your new zone.
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.

Sunrise 6:59AMSunset 6:58PM Monday September 27, 2021 10:09 PM PDT (05:09 UTC) Moonrise 9:57PMMoonset 12:26PM Illumination 57% Phase: Waning Gibbous; Moon at 21 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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PZZ531 San Francisco Bay South Of The Bay Bridge- 907 Pm Pdt Mon Sep 27 2021
.small craft advisory in effect from Tuesday afternoon through Tuesday evening...
Tonight..W winds 10 to 15 kt. A slight chance of rain.
Tue..NW winds 15 to 20 kt with gusts up to 30 kt.
Tue night..W winds 15 to 20 kt with gusts up to 30 kt.
Wed..W winds 10 to 15 kt.
Wed night..NW winds around 5 kt.
Thu..W winds 10 to 15 kt.
Fri..W winds 5 to 10 kt.
PZZ500 907 Pm Pdt Mon Sep 27 2021
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Northwest winds have returned to the waters. Locally stronger winds are forecast to persist along the big sur coast south of point sur. Winds will then gradually strengthen later on Tuesday and remain elevated through mid to late week. Mixed seas remain with a moderate period northwest swell and a longer period southerly swell. An additional larger northwest swell will arrive tonight with seas quickly building into Tuesday. The combination of stronger winds and building swell will result in hazardous seas conditions, particularly for smaller vessels. Seas will begin to subside on Wednesday.


7 Day Forecast for Marine Location Near Castro Valley, CA
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location: 37.71, -122.07     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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FXUS66 KMTR 280456 AFDMTR

Area Forecast Discussion National Weather Service San Francisco Bay Area 956 PM PDT Mon Sep 27 2021

SYNOPSIS. An early season cold front will taper off overnight and bring continued light rain overnight. Breezy to locally gusty onshore winds during the frontal passage are expected today followed by a brief period of breezy to locally gusty offshore winds on Tuesday. Temperatures will be below seasonal averages through Tuesday. A gradual warming and drying trend is then expected for the latter half of the week with lighter winds.

DISCUSSION. as of 09:45 PM PDT Monday . A broad, early season storm system is impacting much of the western CONUS and British Columbia this evening. The core of the storm has transitioned from the eastern Gulf of Alaska into western Canada and the Pacific Northwest where heavy rain and even a few thunderstorms developed. The lower level cold front along the southeastern flank of this storm system has stretched as far south as the San Francisco Bay Area this evening and has brought light rain across the North Bay, San Francisco Peninsula, and portions of the interior bayshore. The highest rainfall totals thus far are concentrated along the North Bay coastal ranges from Gualala (0.57") southward to Point Reyes (0.09"), though a few standouts across the interior ranges are present as well (up to 0.30" near Mt St Helena). Meanwhile, a few of the more populated areas have seen up to 0.05", such as Santa Rosa, Half Moon Bay, and San Francisco. Generally speaking, this storm system has so far outperformed (the minimal) model expectations both during the pre-frontal period and along the main cold frontal rain band and appears to be continuing to outperform the latest HRRR (hi-res) data as of the latest hours, so would not be too shocked to see additional very light precipitation accumulations farther south and east than originally projected as the front tapers off overnight. In fact, just received a report at 930pm of precipitation as far south as Pacific Grove.

Another hazard to highlight tonight into tomorrow night is that we have a building NW swell that will impact our beaches. This is the first significant shift in the seas since last spring. Please see the BEACHES discussion below for more details.

Today's storm system will likely be the last of the 2020-2021 water year, with the new water year beginning in just a few more days (October 1st). While it is also not the first fall-like storm we've had in recency (that honor goes to the system that arrived back on September 18th), it is the first storm system since fall officially began last week, so that is something! The rainfall arriving from this storm system will do little to improve the drought stricken 2020-2021 water year percentage of normal numbers for the region, which are generally in the 35-50 percent of normal range. What it will do, however, is at least temporarily abate fire weather concerns that could have otherwise developed in the wake of this early season storm system. These early season storm systems are notorious for bringing little rainfall as far south as the San Francisco Bay Area, and generally herald in the arrival of dry, gusty offshore flow as they exit the area a day or two later. This storm, much like the one 9 days ago, will follow this pattern, and gusty offshore winds and a drier atmosphere will develop over the region from Tuesday to Thursday.

In the wake of the front, breezy to locally gusty northerly winds will develop across the coast and higher terrain. The windiest locations, such as the coast and higher terrain of the interior North and East Bay, could see gusts peaking up to around 30 to 40 mph. Fire concerns initially be minimal given the fairly saturated atmosphere and recent light rains for many of the areas of possible concern. With persistent offshore flow and building high pressure into midweek, the atmosphere will see a robust drying trend between tomorrow and Thursday. Widespread dry to very dry conditions are then expected midday Thursday as high pressure amplifies overhead, with locally critically dry conditions possible in the driest locations. That said, winds look to ease by the time the ridge amplifies enough to bring these critically dry conditions, and given the recent overperformance of rain with tonight's frontal push, it seems unlikely a fire weather watch will be needed at this time. That said, we will continue to monitor the winds, humidity, and fuels for possible overlap of high fire danger.

AVIATION. as of 5:30 PM PDT Monday . For the 00z TAFs. A cold front moving over the North Bay area this afternoon, giving KSTS/KAPC chances for RA through 04Z. Visibilities will be reduced for the RA passing to around 2-3SM. SCT-BKN015-035 are currently ahead of the front at KOAK/KSFO. VCSH/-RA will move into the Bay Area around 05Z, and linger until 09Z. The front will weaken as it moves south. KSNS/KMRY will have the lowest chances for RA, and will more likely see VCSH starting around 08Z. As RA clears out of KSTS/KAPC tonight, BR/FG is highly likely and will bring in IFR visibilities and ceilings from 10-15Z. VFR skies behind the front for tomorrow, with breezy northwest winds. Winds will become gusty near KSFO/KSTS/KSNS tomorrow afternoon.

Vicinity of KSFO . A FROPA will bring -RA and VCSH to the Bay Area later tonight. MVFR ceilings will move in around 05Z, and RA should start around 06-07Z. Patchy BR possible with potential 4SM visibilities lasting a few hours after the RA ends. After 12Z, skies will clear out to SKC. Breezy northwest winds tomorrow afternoon, with gusts up to 24kts.

KSFO Bridge Approach . Similar to KSFO.

Monterey Bay . Low clouds are bring pushed inland over KSNS ahead of approaching FROPA. The front will pass over later tonight, around 08-10Z. There is a chance for BR/DZ ahead of front at KMRY starting around 05-06Z. Higher confidence in DZ/VCSH, as front breaks up by the time it reaches KMRY/KSNS. VFR ceilings tomorrow morning and afternoon, with breezy northwest winds.

BEACHES. After a fairly quiet summer in terms of swell, the first larger northwest swell of the season will arrive tonight. Swell heights of 8 to 10 feet at 13 to 15 seconds are forecast. Expect an increased risk of moderate to large breaking waves (13 to 17 feet) and stronger rip currents. Additionally, increasing winds behind a cold frontal passage in combination with this building swell may cause waves to run up farther along area beaches than usual. Waves will be capable of knocking down beach goers with a risk of being dragged into the cold turbulent ocean waters. Therefore, a Beach Hazards Statement has been issued from 11 PM Monday to 11 PM Tuesday. This hazard is primarily for west to northwest facing beaches. Caution is urged, and it is recommended to stay off of rocks and jetties. Never turn your back to the ocean. Northwest swell will gradually subside on Wednesday.

MARINE. as of 09:07 PM PDT Monday . Northwest winds have returned to the waters. Locally stronger winds are forecast to persist along the Big Sur coast south of Point Sur. Winds will then gradually strengthen later on Tuesday and remain elevated through mid to late week. Mixed seas remain with a moderate period northwest swell and a longer period southerly swell. An additional larger northwest swell will arrive tonight with seas quickly building into Tuesday. The combination of stronger winds and building swell will result in hazardous seas conditions, particularly for smaller vessels. Seas will begin to subside on Wednesday.

MTR WATCHES/WARNINGS/ADVISORIES. Tngt. SCA . Pt Reyes to Pigeon Pt 0-10 nm from 3 AM SCA . Pigeon Pt to Pt Pinos 0-10 nm from 3 AM SCA . Pigeon Pt to Pt Piedras Blancas 10-60 nm from 3 AM SCA . Pt Arena to Pt Reyes 0-10 nm from 9 PM SCA . Pt Arena to Pigeon Pt 10-60 nm from 9 PM SCA . Pt Pinos to Pt Piedras Blancas 0-10 nm SCA . Mry Bay until 9 PM



PUBLIC FORECAST: DRP AVIATION: Dhuyvetter MARINE: Dhuyvetter

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LNDC1 13 mi52 min WSW 5.1 G 7 62°F 1017.6 hPa
AAMC1 - 9414750 - Alameda, CA 13 mi52 min W 6 G 11 62°F 67°F1018 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 15 mi52 min W 8.9 G 14
OKXC1 - 9414776 - Oakland (Berth 34), CA 16 mi52 min W 8.9 G 9.9 61°F 1017.5 hPa
OBXC1 16 mi52 min 62°F
RTYC1 - 9414523 - Redwood City, CA 16 mi52 min W 7 G 11 64°F 1018.6 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 18 mi52 min W 7 G 13 61°F 1016.4 hPa
PXSC1 18 mi52 min 62°F 62°F
PPXC1 - 9414847 - Richmond (Point Potrero), CA 21 mi52 min WNW 17 G 20 66°F 1017.5 hPa
FTPC1 - 9414290 - San Francisco, CA 22 mi52 min W 7 G 9.9 61°F 65°F1017.7 hPa
RCMC1 - 9414863 - Richmond, CA 23 mi190 min S 4.1 G 8.9 63°F 65°F1016.3 hPa (-0.5)
MZXC1 - 9415102 - Martinez-Amorco CA 23 mi52 min WSW 14 G 18 65°F 68°F1016.8 hPa
PCOC1 - 9415144 - Port Chicago, CA 24 mi52 min WSW 9.9 G 17 65°F 69°F1016.5 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 25 mi52 min W 12 G 19 65°F 1015.8 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 26 mi52 min WNW 13 G 16 65°F 1016.8 hPa
46237 - San Francisco Bar, CA (142) 30 mi70 min 60°F 60°F4 ft
SFXC1 - San Francisco Bay Reserve, CA 34 mi85 min W 11 65°F 1017 hPa59°F
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 41 mi40 min NW 18 G 21 59°F1018.6 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 49 mi40 min NW 16 G 19 60°F 1018.9 hPa58°F

Wind History for Alameda, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hayward, Hayward Air Terminal, CA4 mi76 minW 1110.00 miOvercast64°F59°F84%1018.2 hPa
Oakland, Metro Oakland International Airport, CA8 mi77 minW 1310.00 miMostly Cloudy64°F59°F84%1017.3 hPa
Livermore, Livermore Municipal Airport, CA13 mi77 minW 710.00 miOvercast64°F59°F84%1016.7 hPa
San Carlos Airport, CA16 mi72 minW 610.00 miMostly Cloudy64°F57°F78%1017.9 hPa
Palo Alto Airport, CA16 mi83 minWNW 610.00 miMostly Cloudy64°F57°F78%1017.6 hPa
San Francisco, San Francisco International Airport, CA17 mi74 minNW 89.00 miMostly Cloudy62°F57°F84%1017.4 hPa
Concord, Buchanan Field, CA19 mi77 minSSW 610.00 miPartly Cloudy65°F58°F78%1015.1 hPa

Link to 5 minute data for KHWD

Wind History from HWD (wind in knots)
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Last 24hrW7W5W4W4CalmCalmSW4NW5CalmSE4SE5SW4SW6SW6W7W10W9W14NW9NW8W14W6W11W9
1 day agoW10W9W7W9W7W5W6W5W5W4W4W5W5NW9NW10NW10W11W10NW10NW11W12W9W7W5
2 days agoNW3NW5N3N5N4N6NW4CalmCalmCalmCalmCalmW7W9W11W13W14NW12W13NW10NW8W7W8W9

Tide / Current Tables for Roberts Landing, 1.3 miles west of, San Francisco Bay, California
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Roberts Landing
Click for Map
Tue -- 12:44 AM PDT     0.98 feet Low Tide
Tue -- 07:01 AM PDT     Sunrise
Tue -- 08:11 AM PDT     5.46 feet High Tide
Tue -- 12:52 PM PDT     3.62 feet Low Tide
Tue -- 02:22 PM PDT     Moonset
Tue -- 05:51 PM PDT     6.41 feet High Tide
Tue -- 06:55 PM PDT     Sunset
Tue -- 06:58 PM PDT     Last Quarter
Tue -- 11:45 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.111.42.133.94.75.25.55.34.84.33.83.63.94.55.46.26.46.25.54.63.52.4

Tide / Current Tables for Oakland Airport SW, South San Francisco Bay, California Current
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Oakland Airport SW
Click for Map
Tue -- 12:20 AM PDT     0.00 knots Slack
Tue -- 03:36 AM PDT     0.43 knots Max Flood
Tue -- 07:02 AM PDT     Sunrise
Tue -- 07:13 AM PDT     -0.00 knots Slack
Tue -- 08:59 AM PDT     -0.25 knots Max Ebb
Tue -- 12:11 PM PDT     0.00 knots Slack
Tue -- 02:22 PM PDT     Moonset
Tue -- 03:11 PM PDT     0.24 knots Max Flood
Tue -- 05:49 PM PDT     -0.00 knots Slack
Tue -- 06:55 PM PDT     Sunset
Tue -- 06:58 PM PDT     Last Quarter
Tue -- 09:16 PM PDT     -0.62 knots Max Ebb
Tue -- 11:45 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.10.10.30.40.40.40.20-0.2-0.2-0.2-0.1-00.10.20.20.20.1-0-0.2-0.5-0.6-0.6-0.4

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NOTE: This section has been updated as of 1/26/2021. If the image you are expecting is not showing, please let me know. You may use the EDIT function to update your location.
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