Saturday, October23, 2021
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Marine Weather and Tides
Los Altos Hills, 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 7:23AMSunset 6:22PM Saturday October 23, 2021 2:38 PM PDT (21:38 UTC) Moonrise 7:15PMMoonset 9:18AM Illumination 91% Phase: Waning Gibbous; Moon at 18 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- 847 Am Pdt Sat Oct 23 2021
.gale warning in effect from late tonight through Sunday evening...
Today..SW winds around 5 kt, increasing to 5 to 10 kt this afternoon. A chance of rain this morning, then rain this afternoon.
Tonight..S winds 15 to 20 kt with gusts up to 30 kt. Rain.
Sun..S winds 20 to 25 kt with gusts up to 45 kt. Rain.
Sun night..SW winds 10 to 20 kt with gusts up to 30 kt. Rain.
Mon..SW winds 10 to 15 kt. Rain.
Mon night..SW winds 5 to 10 kt. A chance of rain.
Tue..S winds 5 to 10 kt. A chance of rain.
Wed..NW winds 5 to 10 kt.
PZZ500 847 Am Pdt Sat Oct 23 2021
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Southerly winds will increase to gales as a strong low pressure system nears the pacific northwest sweeping a cool frontal system across our coastal waters later Sunday into Monday morning. An atmospheric river will accompany this frontal system bringing heavy rain later in the weekend. Expect strong and gusty southerly winds, steepening waves and large swell Sunday into Monday. Chilly and showery weather continuing Tuesday. Drier mid to late next week.


7 Day Forecast for Marine Location Near Los Altos Hills, CA
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location: 37.35, -122.18     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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FXUS66 KMTR 231928 AFDMTR

Area Forecast Discussion National Weather Service San Francisco Bay Area 1228 PM PDT Sat Oct 23 2021

SYNOPSIS. Dry conditions this morning. Light rain will develop over the North Bay and along the coastal ranges this afternoon ahead of the upcoming atmospheric river. Rainfall will increase in coverage Sunday and be accompanied by gusty winds before shifting southward across the entire region Sunday night through early Monday morning. A slight chance of North Bay light rain Tuesday otherwise warming and drying trend as high pressure rebuilds.

DISCUSSION. as of 09:02 AM PDT Saturday . Saturday is starting off with building cloud cover and cool conditions as most areas are still in the 50s. The North Bay has lingering pockets of thick fog which look to last until the late morning.

Overall confidence in the forecast is strong for Sunday's AR event. The next forecast update may only be limited to minor tweaks in the timing of rainfall as shorter-term, high-resolution models offer a slight slowdown in the passage of the rain band. For now this doesn't look to change too much in the rainfall amounts, nor does it greatly change the timing of the event, but it will be monitored closely.

Ahead of the event, we recommend taking today as a day of preparation. Today is a perfect day to make sure you are ready for the strong winds, moderate to heavy rain, and the possibility of power outages. Charge your phone and battery back ups, tie down outdoor furniture and trash cans, check your emergency kit supplies, know where and how to get updates from your local emergency management, and clear storm drains and gutters.

PREV DISCUSSION. as of 3:55 AM PDT Saturday . Its the calm before the storm with mostly cloudy skies and mild temperatures in the 50s this morning. One last weak system will approach the region by this afternoon with some light rain breaking out across the North Bay and eventually the SF Peninsula coastline by late afternoon. Any rainfall today will be light in nature. Warm advection rains will begin in earnest overnight across the North Bay with incoming AR taking aim at Mendocino county initially but with moderate rain developing across the North Bay after midnight and through sunrise Sunday morning.

By around 12-15z some light rain will develop across the Bay Area and Santa Cruz mountains but in general rain will remain light south of the Golden Gate through midday Sunday except locally moderate in the Santa Cruz mountains as strong southwest winds align with the coastal slopes. TPW analysis shows the AR/moisture plume with values around 1.85 inches. TPW values approaching 200% of normal as the long moisture plume stretches back across the Pacific.

Would like to emphasize that the heavy rain stays north of the Golden Gate through midday Sunday so our anxious friends in the East and South Bay will have to be patient before the AR starts to drop southward.

In general model timing and intensity has been consistent and on track. If anything have noticed perhaps a slight delay in the southward drift with the heaviest rain associated with the main hose forecast over the greater Bay Area later Sunday afternoon and evening. The exceptionally strong boundary layer winds will keep rainshadowing strong in the usual dry spots of the East and South Bay but the deep moisture will get squeezed out in the East Bay hills and even the hills around Mt Hamilton, though much heavier for the Santa Cruz mountains. No changes made to timing of existing flash flood watches and wind advisories which are timed with the frontal boundary shifting southward through the day and into Sunday evening. Though the main concern is the 2020 burn scars do expect urban and small stream flooding due to the excessive rain rates and likely clogging of storm drains, etc. Again today is the day to complete routine storm maintenance around your property. Low level jet shows 50-60kt flow at 925 mb so downed trees and limbs will be likely especially as soils approach saturation in places like the CZU burn scar. The combination of strong winds and heavy rain will be a nasty combination. Please plan accordingly. Avoid unnecessary travel during the peak of the storm and never cross flooded roadways.

The main boundary looks to drift through the South Bay and Santa Cruz mountains early Sunday evening before reaching the Monterey Bay region later Sunday evening and overnight. Heavy rain likely into the Santa Lucia range above Highway 1 that will be another test for the 2020 burn scars across Monterey county.

Storm totals in the 6-9 inch range for the North Bay mountains appear likely with 3-6 inches Santa Cruz and Santa Lucia. 1-3 inches for the valleys, except 1 inch of less Salinas Valley.

Steady rain rapidly turns to showers late Sunday night into early Monday morning on the backside of the AR with a much cooler airmass aloft. Shower chances continue Monday but the main event will have ended. Another weak impulse on Tuesday will keep the chance of light rain for the North Bay but with only light precip.

Looks like ridging will try and rebuild midweek with seasonably mild and dry weather returning.

AVIATION. as of 11:15 AM PDT Saturday . For the 18z TAFs. A strong storm system will impact the terminal towards the tail end of the TAF period into Monday, with gradually increasing aviation impacts at terminals prior to the arrival of the storm. For today, conditions are split, with IFR to MVFR cigs and light rain across the North Bay, and generally VFR and drier conditions southward. Winds are generally light SW to SE across the interior, with more westerly component nearshore. Conditions will deteriorate from north to south beginning late this evening through the overnight hours, with poor aviation conditions through the day Sunday and into Sunday night until the atmospheric river shifts southward. Ahead of the front, SW 40-60KT LLWS at 1000-2000 feet is expected, becoming gusty southerly winds in the range of 20-45kt late tonight into Sunday. Expect moderate to heavy rain to accompany the gusty winds with very high rain rate intensity with the main band of precipitation leading to slippery runways. Visibility may also drop significantly with the strong wind and heavy rain with lowering cigs as well. Conditions improve in the post frontal environment but lingering showers and potentially some isolated thunderstorms are possible after the heaviest rain shifts southward.

Vicinity of KSFO . VFR but with lowering ceilings from the north today. Light rain by tonight, steadier and much heavier rain Sunday. Light southwesterly wind shifting to southeasterly at 8 to 10 knots late today and this evening, winds aloft strengthening tonight and Sunday resulting in SW 35-55 kt low level wind shear. Gusty southerly surface winds are then expected to arrive by sunrise tomorrow before peaking through midday. Wind gusts of 30 to 50 mph are possible and an airport weather warning for these winds is likely.

KSFO Bridge Approach . Similar to KSFO.

Monterey Bay . VFR today with increasing high clouds from the north. MVFR cigs overnight with possible light warm sector rain. Winds generally light diurnal today. Marginal SE LLWS of 35-45kt then expected through tomorrow morning with increasing southerly surface winds and gusts through tomorrow.

BEACHES. as of 12:30 PM PDT Saturday . A strong, early season storm system arrives tomorrow and will result in significantly increased wave energy from late Sunday into early Tuesday as it arrives and after it passes. This wave energy will transition through the coastal waters from late Sunday into Tuesday, and peak on Monday. Swell of 16 to 24 feet at 16 to 18 seconds is forecast to arrive with the swell train as it peaks on Monday and result in a number of coastal hazards. These hazards include large breaking waves of 20 to 30 feet (higher at favored break points), increased risk of strong longshore and rip currents, increased risk of coastal erosion and minor coastal flooding, and enhanced coastal run up concerns due to the summer beach profiles in place. Due to the early arrival of these large waves, many beaches are still transitioning from their summer beach profiles and lack the features and steepness to resist larger wave run up on coasts. This means that more of this wave energy will have a chance to move onto the beach and overtake individuals, potentially injuring them, or pulling them into the cold ocean. Each year, people die at the coast due to these or similar ocean conditions. A high surf warning for the entire coast has been issued for this threat and is in effect from 11PM Sunday to 11AM Tuesday, with the highest risks once again at west to northwest facing beaches.

MARINE. as of 12:28 PM PDT Saturday . Southerly winds will increase to gales as a strong low pressure system nears the Pacific Northwest sweeping a cool frontal system across our coastal waters later Sunday into Monday morning. An atmospheric river will accompany this frontal system bringing heavy rain later in the weekend. Expect strong and gusty southerly winds, steepening waves and large swell Sunday into Monday. Chilly and showery weather continuing Tuesday. Drier mid to late next week.

MTR WATCHES/WARNINGS/ADVISORIES. Tngt. Wind Advisory . CAZ006-508>513-529 Wind Advisory . CAZ505>507 SCA . Mry Bay from 3 AM SCA . Pigeon Pt to Pt Pinos 0-10 nm from 3 AM SCA . Pt Pinos to Pt Piedras Blancas 0-10 nm from 3 AM SCA . Pt Arena to Pt Reyes 0-10 nm until 3 AM SCA . Pt Arena to Pigeon Pt 10-60 nm until 3 AM SCA . Pigeon Pt to Pt Piedras Blancas 10-60 nm until 3 AM GLW . Pt Arena to Pt Reyes 0-10 nm from 3 AM GLW . Pt Arena to Pigeon Pt 10-60 nm from 3 AM GLW . Pt Reyes to Pigeon Pt 0-10 nm from 3 AM GLW . Pigeon Pt to Pt Piedras Blancas 10-60 nm from 3 AM GLW . SF Bay from 5 AM



PUBLIC FORECAST: RWW/Murdock AVIATION: DRP MARINE: DRP

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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 11 mi51 min NE 5.1G8.9 64°F 1014.2 hPa
46269 30 mi39 min 57°F 57°F8 ft
AAMC1 - 9414750 - Alameda, CA 30 mi51 min ESE 6G8 61°F 61°F1013.8 hPa
LNDC1 31 mi51 min S 7G9.9 63°F 1013.3 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 32 mi51 min SSE 7G11
OBXC1 33 mi51 min 64°F
PXSC1 33 mi51 min 61°F 61°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 33 mi51 min ESE 6G9.9 60°F 1012.4 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 33 mi51 min S 8G11 63°F 1013.3 hPa
FTPC1 - 9414290 - San Francisco, CA 35 mi51 min S 8G11 62°F 70°F1013.4 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 37 mi29 min SSE 14G19 58°F 1014.1 hPa57°F
46237 - San Francisco Bar, CA (142) 39 mi39 min 56°F 56°F8 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 40 mi51 min S 4.1G5.1 62°F 1014 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 40 mi118 min ENE 6 60°F 1015 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi29 min SSE 7.8G12 58°F 58°F1014.7 hPa
RCMC1 - 9414863 - Richmond, CA 41 mi51 min SSE 5.1G8 60°F 60°F1013.6 hPa
46092 - MBM1 42 mi84 min WSW 3.9 57°F 58°F1014.9 hPa (-0.3)
MLSC1 - Moss Landing, South Harbor, CA 43 mi35 min 58°F
ELXC1 - Elkhorn Slough Reserve, CA 44 mi54 min WNW 4.1 64°F 1017 hPa54°F
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 45 mi29 min S 14G19 57°F1014.2 hPa
46114 - West Monterey Bay, CA 46 mi43 min 59°F11 ft
MZXC1 - 9415102 - Martinez-Amorco CA 47 mi51 min SW 8.9G12 63°F 62°F1013.8 hPa
PCOC1 - 9415144 - Port Chicago, CA 49 mi51 min W 9.9G12 62°F 63°F1013.6 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 49 mi51 min W 8G11 60°F 1013.4 hPa

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Palo Alto Airport, CA10 mi52 minENE 610.00 miPartly Cloudy64°F50°F60%1013.5 hPa
San Jose, San Jose International Airport, CA13 mi46 minN 010.00 miMostly Cloudy67°F48°F51%1013.1 hPa
San Carlos Airport, CA13 mi52 minN 010.00 miMostly Cloudy64°F50°F60%1013.9 hPa
San Jose / Reid / Hillv, CA19 mi52 minE 410.00 miPartly Cloudy68°F46°F46%1013.5 hPa
Half Moon Bay Airport, CA20 mi44 minS 96.00 miA Few Clouds with Haze61°F55°F83%1014.2 hPa
San Francisco, San Francisco International Airport, CA21 mi43 minSSW 810.00 miMostly Cloudy64°F49°F58%1013.3 hPa
Hayward, Hayward Air Terminal, CA22 mi45 minW 410.00 miPartly Cloudy65°F49°F56%1014.1 hPa
Oakland, Metro Oakland International Airport, CA24 mi46 minVar 410.00 miMostly Cloudy65°F51°F61%1013.5 hPa

Link to 5 minute data for KNUQ

Wind History from NUQ (wind in knots)
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SE11S6SW5SW9W8SW5S5S7S40S5SE7
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1 day ago------------------------S10S9S7
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2 days ago------------------------------------------------

Tide / Current Tables for Palo Alto Yacht Harbor, California
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Palo Alto Yacht Harbor
Click for Map
Sat -- 03:19 AM PDT     6.80 feet High Tide
Sat -- 07:24 AM PDT     Sunrise
Sat -- 09:53 AM PDT     3.06 feet Low Tide
Sat -- 10:18 AM PDT     Moonset
Sat -- 03:01 PM PDT     8.17 feet High Tide
Sat -- 06:20 PM PDT     Sunset
Sat -- 08:14 PM PDT     Moonrise
Sat -- 10:21 PM PDT     0.36 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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Tide / Current Tables for Dumbarton Point 2.3 mi NE, South San Francisco Bay, California Current
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Dumbarton Point 2.3 mi NE
Click for Map
Sat -- 12:25 AM PDT     1.31 knots Max Flood
Sat -- 03:50 AM PDT     -0.00 knots Slack
Sat -- 07:24 AM PDT     Sunrise
Sat -- 07:33 AM PDT     -0.69 knots Max Ebb
Sat -- 09:40 AM PDT     0.00 knots Slack
Sat -- 10:18 AM PDT     Moonset
Sat -- 12:08 PM PDT     0.87 knots Max Flood
Sat -- 02:53 PM PDT     -0.00 knots Slack
Sat -- 06:19 PM PDT     Sunset
Sat -- 07:41 PM PDT     -1.24 knots Max Ebb
Sat -- 08:14 PM PDT     Moonrise
Sat -- 10:23 PM PDT     0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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