Thursday, May24, 2018 L-36.com


Marine Weather and Tides
Portola Valley, CA

Version 3.4
What's New / NOTES
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.

Sunrise 5:50AMSunset 8:19PM Thursday May 24, 2018 7:05 AM PDT (14:05 UTC) Moonrise 2:37PMMoonset 2:23AM Illumination 73% Phase: Waxing Gibbous; Moon at 10 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 Coastal Waters From Pigeon Point To Point Pinos California Out To 10 Nm- 300 Am Pdt Thu May 24 2018
Today..W winds 5 to 10 kt. Wind waves 2 ft or less. Mixed swell nw 4 to 5 ft at 12 seconds and S 3 to 4 ft at 16 seconds.
Tonight..S winds 5 to 10 kt. Wind waves 2 ft or less. Mixed swell W 4 to 5 ft at 12 seconds and S 3 to 4 ft at 15 seconds. A chance of showers.
Fri..S winds 5 to 15 kt. Wind waves 2 ft or less. Mixed swell W 4 to 5 ft at 11 seconds and S around 3 ft at 15 seconds. A chance of showers.
Fri night..NW winds 5 to 15 kt. Wind waves 2 ft or less. Mixed swell W 4 to 5 ft at 11 seconds and S around 3 ft at 14 seconds.
Sat..NW winds 15 to 25 kt with gusts up to 30 kt. Wind waves 3 to 5 ft. Mixed swell nw 4 to 5 ft at 11 seconds and S around 3 ft at 14 seconds.
Sat night..NW winds 15 to 25 kt with gusts up to 35 kt. Wind waves 3 to 5 ft. NW swell 3 to 4 ft at 11 seconds.
Sun..NW winds 5 to 15 kt. Wind waves 2 ft or less. NW swell 3 to 5 ft.
Memorial day..NW winds up to 10 kt. Wind waves 2 ft or less. NW swell 4 to 6 ft.
PZZ500 300 Am Pdt Thu May 24 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Generally light winds across the waters today and tonight. The strongest winds today will be located in the northern san francisco bay. Northwest winds pick up by mid day tomorrow and become locally moderate by tomorrow night through the upcoming weekend. Mixed seas with a longer period southwest swell and a smaller northwest swell. Increasing winds later this weekend will bring locally steep fresh swell.

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 241151
afdmtr
area forecast discussion
national weather service san francisco bay area
451 am pdt Thu may 24 2018

Synopsis Cloudy and cool today with increasing chance of
showers tonight into Friday as a late season low passes over the
region. Shower chances end by early Saturday morning. High
pressure builds Sunday through Tuesday with a noted warming and
drying trend.

Discussion As of 3:42 am pdt Thursday... Satellite shows low
clouds covering most of the region with high clouds now starting
to increase as well ahead of incoming upper low. Current obs show
cloud bases around 1500 feet most locations with another morning
of drizzle likely with abundant low level moisture and incoming
synoptic lift. Combination of cloud cover and fairly cool airmass
will mean another day of afternoon highs mainly in the 60s except
some 70s far interior valleys of the central coast.

Main forecast item of note will be shower chances with incoming
upper low. 06z NAM and latest rap model indicate slight shower
chances by late this afternoon early evening over the coastal
hills of monterey county. Any late day breaks in the clouds will
help with some destabilization. Timing of upper low, which has
been pretty consistent for days now brings the core of the coldest
air through late tonight into early Friday morning. Thus we wont
have peak heating for instability. Nonetheless enough instability
to generate shower chances across much of the region Friday
morning. There remains a slight chance of thunder but for now the
forecast will just show showers as confidence for t-storms remains
low which is supported by latest SPC general convective outlook
for Friday. Main impact will be for the Friday morning commute
when some rogue showers could produce wet roads with some brief
moderate showers possible. QPF numbers should be light, on the
order of a few hundredths for areas that receive showers although
localized amounts up to 0.25 will be possible.

The main shower threat should end as the Sun GOES down Friday
night but will hold onto slight chance showers through about
sunrise Saturday. Saturday will be a cool start to the holiday
weekend as we'll be on the backside of the upper low with
continued strong onshore flow and cold air aloft.

Good news for the holiday weekend is building high pressure should
bring much more sunshine and warmer temperatures for Sunday and
memorial day with lots of highs back into the 70s and 80s away
from the coast. The surface pattern may even generate some
northerly flow which would even clear clouds at most beaches for
the second half of the holiday weekend.

Above normal temps to stay in place through Tuesday before the
next cool trough arrives midweek with another cooling trend.

Aviation As of 4:50 am pdt Thursday... Widespread MVFR cigs
forecast to persist thru at least mid morning. Approaching upper
trof has allowed marine layer to deepen to approximately 3000 ft,
with a depth of around 1000 feet. This is leading to cig bases
predominately around 1500-2000 ft. Expect sct with some patchy bkn
clouds to persist in the low to mid level into the late morning or
possibly early afternoon at some terminals. Onshore winds locally
breezy with occasional gusts to around 20kt at the windiest spots.

Vcsh at the end of the TAF period.

Vicinity of ksfo... MVFR thru 17-18z this morning, then lingering
few-sct low to mid level clouds as upper trof arrives. Breezy
onshore winds up to around 15k with gusts to around 20kt thru the
afternoon. BorderlineVFR MVFR CIGS towards the end of the taf
period with vcsh.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... MVFR thru the mid to possibly late
morning around the monterey bay. Onshore winds to around 12 kt
with local gusts to around 18kt. Low to mid level few to sct
clouds will linger around the terminals thru the afternoon with
early return of borderline MVFRVFR CIGS by the evening.

Marine As of 04:45 am pdt Thursday... Generally light winds
across the waters today and tonight. The strongest winds today
will be located in the northern san francisco bay. Northwest winds
pick up by mid day tomorrow and become locally moderate by
tomorrow night through the upcoming weekend. Mixed seas with a
longer period southwest swell and a smaller northwest swell.

Increasing winds later this weekend will bring locally steep fresh
swell.

Mtr watches warnings advisories
Tday Sca... Sf bay from 3 pm
public forecast: rww
aviation: drp
marine: drp
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 10 mi47 min W 8 G 9.9 53°F 64°F1017.1 hPa
AAMC1 - 9414750 - Alameda, CA 29 mi47 min W 6 G 8 54°F 62°F1016.6 hPa
LNDC1 30 mi47 min WSW 5.1 G 8 55°F 1016.4 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 31 mi47 min W 4.1 G 7 54°F 1015.4 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 31 mi47 min W 8.9 G 11
OBXC1 31 mi47 min 55°F 50°F
PXSC1 32 mi47 min 55°F 50°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 32 mi47 min SW 4.1 G 9.9 54°F 1016.5 hPa
FTPC1 - 9414290 - San Francisco, CA 33 mi47 min W 6 G 8.9 54°F 57°F1016.6 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 35 mi75 min E 1.9 G 1.9 53°F 55°F5 ft1016.2 hPa (+0.0)
46237 - San Francisco Bar, CA (142) 36 mi65 min 54°F6 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 38 mi47 min SW 5.1 G 8 55°F 1016.6 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 39 mi186 min SW 5.1 53°F 1017 hPa
RCMC1 - 9414863 - Richmond, CA 40 mi47 min WNW 1.9 G 4.1 55°F 59°F1016.1 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi75 min NW 3.9 G 3.9 54°F 55°F7 ft1016.5 hPa (+0.3)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 42 mi55 min SW 3.9 G 3.9 53°F 52°F1016.9 hPa53°F
46092 - MBM1 43 mi120 min WNW 7.8 54°F 54°F1016.5 hPa (+0.0)
46114 - West Monterey Bay, CA 44 mi65 min 55°F6 ft
ELXC1 - Elkhorn Slough Reserve, CA 46 mi80 min W 2.9 54°F 1017 hPa50°F
MZXC1 - 9415102 - Martinez-Amorco CA 47 mi47 min WSW 8.9 G 12 55°F 63°F1016 hPa55°F
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 48 mi53 min W 8 G 12 55°F 1015.8 hPa
PCOC1 - 9415144 - Port Chicago, CA 49 mi47 min SW 12 G 15 55°F 64°F1015.6 hPa

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Palo Alto Airport, CA10 mi18 minNW 810.00 miOvercast55°F48°F77%1016.9 hPa
Mountain View, Moffett Field, CA11 mi69 minVar 410.00 miOvercast55°F48°F77%1016.7 hPa
San Carlos Airport, CA12 mi70 minWNW 510.00 miOvercast54°F46°F77%1016.6 hPa
San Jose, San Jose International Airport, CA16 mi72 minNW 510.00 miOvercast56°F48°F75%1016.3 hPa
Half Moon Bay Airport, CA18 mi70 minN 010.00 miOvercast52°F48°F88%1016.9 hPa
San Francisco, San Francisco International Airport, CA19 mi69 minWSW 410.00 miOvercast55°F46°F72%1016.4 hPa
Hayward, Hayward Air Terminal, CA22 mi71 minW 610.00 miOvercast54°F48°F80%1017.2 hPa
Oakland, Metro Oakland International Airport, CA23 mi72 minN 010.00 miOvercast53°F48°F83%1016.5 hPa

Wind History from PAO (wind in knots)
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Last 24hr4--5SW9--------NW13--SW15----NW9------------------NW8
1 day agoCalm----NW4NW6--NW10NW8
G15
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G15
NW14NW12NW10NW10NW5------------------Calm
2 days agoCalmSE8----N6--NW13--NW15NW15NW15NW15NW10NW10------------------4

Tide / Current Tables for Granite Rock, Redwood Creek, San Francisco Bay, California
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Granite Rock
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Thu -- 03:23 AM PDT     Moonset
Thu -- 04:06 AM PDT     1.27 feet Low Tide
Thu -- 05:53 AM PDT     Sunrise
Thu -- 09:27 AM PDT     6.24 feet High Tide
Thu -- 03:36 PM PDT     Moonrise
Thu -- 03:50 PM PDT     0.59 feet Low Tide
Thu -- 08:18 PM PDT     Sunset
Thu -- 10:13 PM PDT     8.32 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
5.84.12.71.71.31.62.645.36.16.15.54.32.91.70.80.61.22.54.267.58.38.1

Tide / Current Tables for Dumbarton Hwy Bridge, South San Francisco Bay, California Current
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Dumbarton Hwy Bridge
Click for Map
Thu -- 01:27 AM PDT     -0.96 knots Max Ebb
Thu -- 03:22 AM PDT     Moonset
Thu -- 04:34 AM PDT     0.00 knots Slack
Thu -- 05:52 AM PDT     Sunrise
Thu -- 07:40 AM PDT     1.34 knots Max Flood
Thu -- 10:11 AM PDT     -0.00 knots Slack
Thu -- 01:31 PM PDT     -0.94 knots Max Ebb
Thu -- 03:36 PM PDT     Moonrise
Thu -- 04:36 PM PDT     0.01 knots Slack
Thu -- 07:57 PM PDT     1.72 knots Max Flood
Thu -- 08:18 PM PDT     Sunset
Thu -- 10:42 PM PDT     -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.8-0.9-0.9-0.8-0.30.30.91.31.310.2-0.4-0.7-0.9-0.9-0.7-0.40.31.11.61.71.50.8-0.2

Weather Map and Satellite Images
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wmap_P
GOES Local Image of CentralWestCoast    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for San Francisco/Monterey Bay Area, CA (10,2,3,4)
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Ground Weather Radar Station San Francisco Bay Area, CA
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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.