Wednesday, September19, 2018 L-36.com


Marine Weather and Tides
Portola Valley, CA

Version 3.4
What's New / NOTES
9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 6:53AMSunset 7:10PM Wednesday September 19, 2018 7:11 PM PDT (02:11 UTC) Moonrise 3:26PMMoonset 12:46AM Illumination 76% 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 Pigeon Point To Point Pinos To 10 Nm- 215 Pm Pdt Wed Sep 19 2018
.small craft advisory in effect through late tonight...
Tonight..NW winds 15 to 25 kt...decreasing to 5 to 15 kt after midnight. Wind waves 3 to 5 ft. NW swell 6 to 7 ft at 10 seconds.
Thu..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. NW swell 5 to 6 ft at 11 seconds.
Thu night..NW winds 10 to 20 kt...decreasing to 10 kt after midnight. Wind waves 3 to 4 ft in the evening...becoming 2 ft or less. NW swell 5 to 6 ft at 10 seconds.
Fri..S winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 5 ft at 10 seconds.
Fri night..S winds 10 kt. Wind waves 2 ft or less. NW swell 3 to 4 ft at 10 seconds.
Sat..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft.
Sun..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft.
Mon..NW winds 10 kt. Wind waves 2 ft or less. NW swell 3 to 4 ft.
PZZ500 215 Pm Pdt Wed Sep 19 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... High pressure to the north and low pressure to the south will keep breezy to gusty northerly winds along the central coast through Thursday evening. Gusty winds will generate steep wind waves creating hazardous sea conditions, especially for smaller vessels. Winds will then diminish late this week as the high pressure weakens and the thermal trough shifts towards the coast.


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 200009
afdmtr
area forecast discussion
national weather service san francisco bay area
509 pm pdt Wed sep 19 2018

Synopsis A warming and drying trend will continue into
Thursday as onshore flow weakens and a brief period of offshore
flow begins. Gusty northerly winds in higher elevations will
result in enhanced fire weather concerns from tonight into
Thursday morning, mainly in the north and east bay mountains and
the santa cruz mountains. Temperatures are expected to moderate
slightly over the upcoming weekend but will remain near to
slightly above seasonal averages as we head into next week.

Discussion As of 1:46 pm pdt Wednesday... The marine layer has
lowered to around 1000 feet per the fort ord profiler output, as
high pressure aloft begins to nudge into the state. Skies have
cleared except for a stubborn patch of low clouds clinging to the
monterey peninsula. Most temperatures are running warmer than
yesterday by several degrees, santa rosa is 10 degrees warmer at
79 degrees! Coastal areas are about the same as yesterday with
upper 50s to mid 60s currently. The northerly surface pressure
gradient continues to tighten with acv-sfo now nearing 6 mb. The
onshore component remains fairly weak with 1 mb from sfo to sac.

The northerly gradient will result in increasing offshore winds
over the higher hills from santa cruz county northward. See below
for how this will affect fire weather.

High pressure aloft will edge into california from the west. This
will usher in a warming trend over the next few days, peaking on
Thursday when high temperatures are forecast to warm into the 90s
across the warmest inland areas, with 60s and 70s along the
coast. Slight cooling is expected over the weekend as an upper
level trough moves across the pacific northwest.

Medium range model runs still indicating a return of high
pressure over the eastern pacific early next week. This will
maintain high temperatures in the around normal or slightly above
normal range.

Aviation As of 5:05 pm pdt Wednesday... Increasing offshore flow
will keep clearVFR conditions in the sfo bay area through
Thursday. Models indicate some low-level moisture could produce
late night clouds in southern mry bay late tonight but given that
clouds were disorganized this morning and the drying trend latest
forecast keepsVFR in the mry bay area. Gusty winds over the north
and east bay hills may produce llws around oak above 2000 feet
Thursday morning.

Vicinity of ksfo...VFR. West winds to 20 kt through 04z.

Sfo bridge approach... .Similar to sfo.

Monterey bay terminals... .Vfr.

Fire weather A tightening northerly surface pressure gradient
will produce gusty winds across the north bay mountains, the east
bay hills and diablo range, and the santa cruz mountains. This
coupled with very poor relative humidity recoveries overnight and
already dry fuels will elevate fire weather concerns in these
areas. A red flag warning has been issued for these areas
beginning tonight at 11 pm and going through 5 pm on Thursday.

Winds will begin diminishing during the day, but continued breezy
conditions and low daytime relative humidity values justify
keeping the rfw through the day. Weaker offshore winds are
expected on Friday, and the flow will return to onshore over the
weekend.

Marine As of 05:03 pm pdt Wednesday... High pressure to the
north and low pressure to the south will keep breezy to gusty
northerly winds along the central coast through Thursday evening.

Gusty winds will generate steep wind waves creating hazardous sea
conditions, especially for smaller vessels. Winds will then
diminish late this week as the high pressure weakens and the
thermal trough shifts towards the coast.

Mtr watches warnings advisories
Tngt Sca... Pt reyes to pigeon pt 0-10 nm until 3 am
sca... Pigeon pt to pt pinos 0-10 nm until 3 am
sca... Pt arena to pigeon pt 10-60 nm
sca... Pigeon pt to pt piedras blancas 10-60 nm
sca... Pt pinos to pt piedras blancas 0-10 nm
sca... Pt arena to pt reyes 0-10 nm
sca... Mry bay until 9 pm
public forecast: sims
aviation: W pi
marine: mm
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 10 mi42 min NNW 5.1 G 7 72°F 70°F1010.3 hPa
AAMC1 - 9414750 - Alameda, CA 29 mi42 min W 6 G 8 68°F1010.4 hPa
LNDC1 30 mi42 min WSW 4.1 G 5.1 69°F 1010 hPa
OBXC1 31 mi42 min 69°F 51°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 31 mi42 min Calm G 1.9
PXOC1 - 9414311 - San Francisco (Pier 1), CA 31 mi42 min SSW 4.1 G 6 68°F 1009 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 32 mi42 min ENE 4.1 G 5.1 70°F 1010 hPa
PXSC1 32 mi42 min 66°F 52°F
FTPC1 - 9414290 - San Francisco, CA 33 mi42 min SW 12 G 18 60°F1010.2 hPa
46237 - San Francisco Bar, CA (142) 36 mi42 min 58°F4 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 38 mi60 min S 7 G 8.9 64°F 1010.2 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 39 mi37 min Calm 73°F 1010 hPa
RCMC1 - 9414863 - Richmond, CA 40 mi42 min SE 2.9 G 5.1 65°F1009.6 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi82 min NNW 21 G 27 57°F 55°F9 ft1009.2 hPa (-2.0)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 42 mi42 min NW 16 G 19 55°F 54°F1011.1 hPa
46092 - MBM1 43 mi67 min WNW 16 56°F 54°F1009.4 hPa (-1.9)
46114 - West Monterey Bay, CA 44 mi42 min 55°F9 ft
ELXC1 - Elkhorn Slough Reserve, CA 46 mi87 min SW 5.1 62°F 1010 hPa55°F
MZXC1 - 9415102 - Martinez-Amorco CA 47 mi42 min W 11 G 12 76°F 69°F1009.2 hPa55°F
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 48 mi60 min WSW 6 G 8.9 75°F 1009.1 hPa
PCOC1 - 9415144 - Port Chicago, CA 49 mi42 min W 12 G 14 77°F 67°F1008.9 hPa

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Palo Alto Airport, CA10 mi25 minN 1310.00 miClear68°F57°F69%1010.2 hPa
Mountain View, Moffett Field, CA11 mi16 minN 1010.00 miFair69°F54°F59%1010.2 hPa
San Jose, San Jose International Airport, CA16 mi19 minNNW 1110.00 miFair73°F50°F44%1009.6 hPa
Half Moon Bay Airport, CA18 mi17 minN 65.00 miFair with Haze57°F50°F77%1011.5 hPa
San Francisco, San Francisco International Airport, CA19 mi16 minWNW 1610.00 miFair62°F48°F62%1009.7 hPa
San Jose / Reid / Hillv, CA22 mi85 minNNW 510.00 miClear79°F51°F39%1009.1 hPa
Hayward, Hayward Air Terminal, CA22 mi18 minW 410.00 miFair69°F54°F59%1010.7 hPa
Oakland, Metro Oakland International Airport, CA23 mi19 minWNW 1010.00 miFair65°F54°F68%1010.2 hPa

Wind History from PAO (wind in knots)
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Last 24hrNW10NW7------------------CalmCalmCalm4N6N8N10NW16------N14N13
1 day agoW12W10------------------Calm----46N10N9N12NW13NW13N15N15--
2 days agoW10W10--------------------CalmSE6SE6NE8N8N12--N14
G20
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G20
W14NW15W13

Tide / Current Tables for Granite Rock, Redwood Creek, San Francisco Bay, California
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Dumbarton Hwy Bridge, South San Francisco Bay, California Current
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Tide / Current data from XTide NOT FOR NAVIGATION
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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 (22,6,7,8)
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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.