Thursday, April27, 2017 L-36.com


Marine Weather and Tides
Portola Valley, CA

Version 3.4
What's New / NOTES
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:14AMSunset 7:56PM Thursday April 27, 2017 7:33 PM PDT (02:33 UTC) Moonrise 6:31AMMoonset 8:35PM Illumination 4% Phase: Waxing Crescent; Moon at 2 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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PZZ560 Pigeon Point To Point Pinos To 10 Nm- 215 Pm Pdt Thu Apr 27 2017
.small craft advisory in effect through Friday evening...
Tonight..NW winds 15 to 25 kt. Wind waves 4 to 6 ft. NW swell 8 to 10 ft at 12 seconds.
Fri..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. NW swell 4 to 6 ft at 11 seconds.
Fri night..NW winds 15 to 25 kt. Wind waves 4 to 6 ft. NW swell 7 to 8 ft at 11 seconds.
Sat..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 5 to 7 ft at 11 seconds.
Sat night..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. W swell 6 to 8 ft.
Sun..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. NW swell 6 to 7 ft...shifting to the west 6 to 8 ft.
Mon..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. W swell 7 to 9 ft.
Tue..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. W swell 8 to 9 ft.
PZZ500 215 Pm Pdt Thu Apr 27 2017
Synopsis for the central california coast and bays including Monterey bay national marine sanctuaries.. Strong northwesterly winds will impact the coastal waters today and Friday as building high pressure tightens the pressure gradient. Some isolated gale force gusts will be possible offshore and near coastal points. Steep seas will develop in response to the winds and a fresh northwest swell will continue to impact the coastal waters through the weekend.

7 Day Forecast for Marine Location Near Portola Valley, CA
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location: 37.36, -122.23     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 272338
afdmtr
area forecast discussion
national weather service san francisco bay area
438 pm pdt Thu apr 27 2017

Synopsis Continued breezy conditions at times on Friday,
particularly near the coast and in the hills, with a gradual
warming trend. Winds will ease by Saturday morning then clear and
warm weather is forecast over the weekend and into early next week
with no rain in the extended forecast.

Discussion As of 2:15 pm pdt Thursday... Synoptic pattern today
features cyclonic flow aloft with strong onshore surface
pressure gradients that have kicked up strong afternoon northwest
winds along the coast and coastal hills.

Overnight as the main longwave trough digs over the great basin the
response along the california coast will be a developing thermal
trough at the surface which will push the winds to a more north or
northeast direction by Friday morning. This will bring some 35 mph
winds to the north and east bay hills Friday morning and allow for
some favorable downslope winds. So under clear skies expect
temperatures to warm well into the 70s to wind out the work week.

Winds will ease for a time Friday afternoon, except right at the
beaches where north winds will continue. Then again Friday night
into Saturday another round of offshore winds will develop in the
hills. This time with a drier and warmer airmass in place. This will
set the stage for a magnificent Saturday morning to start out the
bay area weekend. If you get out early enough you'll almost be able
to smell the warmth as the offshore winds usher in a drier airmass
with no marine layer to speak of. Saturday should be the warmest day
so far this year for many locations with highs climbing into the 80s
for may of the inland valleys, especially in the north and east bay
where favorable downslope wind flow will continue.

By Sunday the offshore winds will have eased but the stage will be
set for several days of ideal spring time weather with clear skies
and daytime highs generally in the 70s and 80s for much of the bay
area and likely even some near 90 degree readings for southern
monterey county.

The earliest it looks like the ridge will break down would be around
next Thursday. Will see if we get any stratus intrusions before that
but it looks like a real nice period of warm and dry weather coming
up for the region.

Aviation As of 4:38 pm pdt Thursday... Near high confidence dry
northerly winds will keepVFR going at the terminals tonight and
Friday. Only exception is there may be a few patchy low clouds
along the immediate coastline early Friday morning, otherwiseVFR
is forecast with few-sct thin cirrus.

Vicinity of ksfo...VFR. Gusty w-nw winds near 30 knots this evening
gradually relaxes tonight, then resumes and becomes gusty from the
w-nw again Friday.

Sfo bridge approach...VFR.

Monterey bay terminals...VFR. Patchy ifr CIGS are possible over the
southern monterey bay area per WRF model output, kmry tempo 12z-16z
bkn 800 feet.

Marine As of 2:15 pm pdt Thursday... The forecast remains on
track with high pressure taking over the weather pattern. The
pressure gradient will tighten across the waters in response to
building high pressure causing northerly winds to increase over
the next couple of days. Wind gusts should reach 25 to 30 kt today
and Friday. Some isolated gale force gusts will even be possible
offshore and near coastal points. Then fresh north winds will
persist into the weekend. Seas will become quite steep due to the
winds and a mid period westerly swell will continue to impact the
waters through the weekend. The existing small craft advisories
will remain in effect.

Mtr watches/warnings/advisories
Tngt Sca... Pt arena to pt reyes 0-10 nm
sca... Pt reyes to pigeon pt 0-10 nm
sca... Pigeon pt to pt pinos 0-10 nm
sca... Pt pinos to pt piedras blancas 0-10 nm
sca... Pt arena to pigeon pt 10-60 nm
sca... Pigeon pt to pt piedras blancas 10-60 nm
sca... Mry bay until 3 am
public/marine: NWS eureka
aviation: canepa
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 10 mi45 min W 19 G 26 60°F 64°F1015.6 hPa
AAMC1 - 9414750 - Alameda, CA 29 mi45 min W 8 G 13 61°F 63°F1016.4 hPa
LNDC1 30 mi51 min W 6 G 8 63°F 1015.7 hPa
OBXC1 31 mi45 min 61°F 47°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 31 mi45 min W 12 G 15
PXOC1 - 9414311 - San Francisco (Pier 1), CA 31 mi45 min WSW 9.9 G 14 61°F 1014.8 hPa
PXSC1 32 mi45 min 61°F 43°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 32 mi45 min W 7 G 9.9 62°F 1015.9 hPa
FTPC1 - 9414290 - San Francisco, CA 33 mi45 min WSW 9.9 G 14 58°F 56°F1016.1 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 35 mi103 min NW 25 G 31 56°F 54°F10 ft1017 hPa (-0.7)
46237 - San Francisco Bar, CA (142) 36 mi63 min 54°F8 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 38 mi45 min W 11 G 17 64°F 1015.9 hPa
RCMC1 - 9414863 - Richmond, CA 40 mi45 min WNW 13 G 18 61°F 58°F1015.2 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi103 min 23 G 29 56°F 56°F11 ft1017.5 hPa (-0.7)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 42 mi103 min NW 25 G 31 55°F 54°F10 ft1017 hPa (-1.1)
46092 - MBM1 43 mi86 min W 21 54°F 1015.5 hPa (-0.0)
46114 - West Monterey Bay, CA 44 mi33 min 55°F10 ft
UPBC1 47 mi45 min WNW 18 G 21
MZXC1 - 9415102 - Martinez-Amorco CA 47 mi45 min W 13 G 18 63°F 60°F1015.2 hPa46°F
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 48 mi45 min W 12 G 17 63°F 1014.9 hPa
PCOC1 - 9415144 - Port Chicago, CA 49 mi45 min W 19 G 21 63°F 61°F1014.4 hPa

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
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G30
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W14
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W17
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G17

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Palo Alto Airport, CA10 mi1.8 hrsNW 16 G 2310.00 miPartly Cloudy66°F46°F49%1016.6 hPa
Mountain View, Moffett Field, CA11 mi97 minNW 12 G 2210.00 miFair65°F37°F36%1016.9 hPa
San Carlos Airport, CA12 mi46 minW 14 G 2810.00 miPartly Cloudy63°F37°F39%1016.3 hPa
San Jose, San Jose International Airport, CA16 mi40 minWNW 16 G 2510.00 miMostly Cloudy63°F36°F37%1016.2 hPa
Half Moon Bay Airport, CA18 mi38 minNNW 23 G 336.00 miFair with Haze and Windy55°F44°F67%1017.3 hPa
San Francisco, San Francisco International Airport, CA19 mi97 minW 28 G 3810.00 miPartly Cloudy and Windy59°F43°F56%1016.4 hPa
San Jose / Reid / Hillv, CA22 mi1.7 hrsNW 1110.00 miPartly Cloudy64°F44°F49%1017.3 hPa
Hayward, Hayward Air Terminal, CA22 mi39 minW 1710.00 miFair62°F44°F52%1017 hPa
Oakland, Metro Oakland International Airport, CA23 mi40 minW 1510.00 miPartly Cloudy64°F48°F56%1016 hPa

Wind History from PAO (wind in knots)
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Last 24hrNW12NW12W15------------------335N5N10N10--NW15NW17NW19NW20NW16
G23
1 day agoW17W10W6------------------CalmCalmCalm--NE5554W15NW10NW15NW15
2 days agoNW15NW11NW12------------------CalmNW10NW10NW14--NW14--NW13
G20
--NW10W15W17

Tide / Current Tables for Granite Rock, Redwood Creek, San Francisco Bay, California
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Granite Rock
Click for Map
Thu -- 01:20 AM PDT     9.04 feet High Tide
Thu -- 06:17 AM PDT     Sunrise
Thu -- 07:31 AM PDT     Moonrise
Thu -- 08:17 AM PDT     -1.12 feet Low Tide
Thu -- 02:37 PM PDT     7.31 feet High Tide
Thu -- 07:55 PM PDT     Sunset
Thu -- 08:17 PM PDT     1.49 feet Low Tide
Thu -- 09:35 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
898.87.85.93.61.3-0.3-1.1-0.80.42.24.267.17.26.55.13.52.21.51.83.15

Tide / Current Tables for Dumbarton Hwy Bridge, South San Francisco Bay, California Current
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Dumbarton Hwy Bridge
Click for Map
Thu -- 02:00 AM PDT     -0.01 knots Slack
Thu -- 05:37 AM PDT     -1.68 knots Max Ebb
Thu -- 06:17 AM PDT     Sunrise
Thu -- 07:30 AM PDT     Moonrise
Thu -- 08:49 AM PDT     0.00 knots Slack
Thu -- 12:01 PM PDT     2.28 knots Max Flood
Thu -- 03:13 PM PDT     -0.00 knots Slack
Thu -- 06:08 PM PDT     -1.09 knots Max Ebb
Thu -- 07:55 PM PDT     Sunset
Thu -- 08:52 PM PDT     0.00 knots Slack
Thu -- 09:34 PM PDT     Moonset
Thu -- 11:58 PM PDT     1.77 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.710-0.6-1.2-1.6-1.6-1.2-0.60.21.222.321.30.3-0.4-0.9-1.1-0.9-0.50.10.91.5

Weather Map and Satellite Images
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Weather Map
wmap_P
IR Satellite Image from GEOS
west_satellite

GOES Local Image of CentralWestCoast    EDIT
Geos

Wind Forecast for San Francisco/Monterey Bay Area, CA (22,6,7,8)
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Ground Weather Radar Station San Francisco Bay Area, CA
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weather_mapweather_map weather_map

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Disclaimer:
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.