Thursday, August17, 2017 L-36.com


Marine Weather and Tides
Belvedere, CA

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
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.

Sunrise 6:26AMSunset 8:00PM Thursday August 17, 2017 4:37 AM PDT (11:37 UTC) Moonrise 1:07AMMoonset 3:45PM Illumination 23% Phase: Waning Crescent; Moon at 25 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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PZZ530 San Pablo Bay Suisun Bay The West Delta And San Francisco Bay North Of The Bay Bridge- 253 Am Pdt Thu Aug 17 2017
.small craft advisory in effect from 1 pm pdt this afternoon through this evening...
Today..SW winds 10 to 20 kt.
Tonight..SW winds 10 to 20 kt.
Fri..SW winds 10 to 20 kt.
Fri night..SW winds 10 to 20 kt.
Sat..SW winds 15 to 25 kt. Patchy fog after midnight.
Sun..SW winds 5 to 15 kt.
Mon..SW winds 5 kt...increasing to 5 to 15 kt.
PZZ500 253 Am Pdt Thu Aug 17 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Light variable winds through the day as an east pacific ridge builds inland to the north while a weak trough lingers just to the south. Expect increasing northwest winds beginning late tomorrow and lasting through the weekend as the ridge strengthens further.

7 Day Forecast for Marine Location Near Belvedere, CA
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location: 37.83, -122.44     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 171119
afdmtr
area forecast discussion
national weather service san francisco bay area
415 am pdt Thu aug 17 2017

Synopsis A gradual inland warming trend can be expected through
late week as high pressure builds over the region. Overnight and
morning clouds will also be common, especially near the coast and in
the adjacent valleys.

Discussion As of 4:14 am pdt Thursday... Skies are clear thus far
over most of napa county, parts of the east bay and south bay, san
benito and interior monterey counties while stratus and fog blanket
the bays and the rest of the coast early this morning. The marine
layer depth is holding steady at 2,000 feet.

The marine inversion is fairly well developed and further strengthening
occurs today into Saturday as increasing subsidence in advance of a
594 decameter closed mid-upper level high centered approx 700 miles
west of the bay area produces large scale sinking and adiabatic warming.

Thermal ridging coincides with geopotential height ridging over norcal
today into at least the first part of the weekend, and per most recent
nam model output warming becomes focused over inland valleys and hills
especially over the bay area counties, and in particular over the north
bay Friday and Saturday. 925 mb level temperatures reach 28c over
north bay tonight and then 30c Friday night meaning temperatures in
the north bay hills and mountains will most likely hover in the
lower to middle 80s all night as the marine layer becomes
increasingly squashed under high pressure. With this in mind, am not
having a whole lot of confidence in daytime maximum temperature
guidance especially for north bay and east bay areas Friday and
Saturday; 90s to near 100 will probably be more common even closer
to the bays as the marine layer becomes increasingly compressed.

Eventually an active mid latitude zonal jet stream crossing the
lower 48 buckles ever so slightly causing a weak and slowly sw
moving upper level trough to form over the west coast and east
pacific by late this weekend into early next week. Model output has
been consistent with showing lower to mid level thermal ridging
weakening over the forecast area while this trough develops, however
with a solidly strong position to start there'll still be remnants
of it to persisting causing the marine layer to persist Sunday into
Monday. At the same time much drier 925 mb rhs sweep in from the
northwest over the weekend probably mixing into the marine based
clouds with a tendency for lower level winds, and possibly surface
winds to go from onshore to having a weak southerly component. The
question is how will all of this influence the marine layer early
next week? It's just a guess that there could be an earlier than
usual clearing Monday morning.

For mid-late next week, a very deep low pressure area develops over
the gulf of alaska. The ecmwf, gfs, gem have been lean toward weak
long-wave troughing over the west coast. The southern extent of the
gulf of alaska low arrives as a trough bringing more pronounced
cooling and increasing onshore winds. Coastal drizzle is a possibility
in a deepening or even possibly a fully mixed out marine layer.

Aviation As of 10:45 pm pdt Wednesday... Marine layer has
compressed to 2000 feet and is expected to compress further as an
upper level ridge builds off the coast. Stratus is on track to
spread into the sfo bay area. The only changes to the previous taf
is to raise the cig heights so that sfo and the approach will
stay MVFR overnight.

Vicinity of ksfo... MVFR ceilings after 10z clearing after 17z.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... MVFR CIGS possibly dipping into ifr
between 12z and 18z.

Marine As of 2:53 am pdt Thursday... Light variable winds through
the day as an east pacific ridge builds inland to the north while
a weak trough lingers just to the south. Expect increasing northwest
winds beginning late tomorrow and lasting through the weekend as
the ridge strengthens further.

Mtr watches warnings advisories
Tday Sca... Sf bay from 1 pm
public forecast: canepa
aviation: W pi
marine: drp
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FTPC1 - 9414290 - San Francisco, CA 2 mi50 min WSW 6 G 8.9 60°F 62°F1015.4 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 3 mi50 min WSW 1.9 G 7 60°F 1014 hPa
PXSC1 3 mi50 min 61°F 58°F
TIBC1 - Tiburon Pier, San Francisco Bay, CA 4 mi61 min ENE 1.9 60°F 1016 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 6 mi50 min W 6 G 8 61°F 1015 hPa
OBXC1 6 mi50 min 61°F 58°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 6 mi50 min W 6 G 8.9
PPXC1 - 9414847 - Richmond (Point Potrero), CA 7 mi50 min SW 8.9 G 12 62°F 1015.4 hPa
RCMC1 - 9414863 - Richmond, CA 7 mi50 min WSW 6 G 8.9 61°F 65°F1015 hPa
AAMC1 - 9414750 - Alameda, CA 8 mi50 min W 5.1 G 7 61°F 69°F1015.5 hPa
LNDC1 9 mi50 min WNW 2.9 G 7 62°F 1015 hPa
46237 - San Francisco Bar, CA (142) 11 mi68 min 60°F5 ft
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 18 mi50 min WSW 9.9 G 15 62°F 1014.7 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 22 mi48 min S 1.9 G 3.9 58°F 57°F4 ft1015.4 hPa (+0.0)
MZXC1 - 9415102 - Martinez-Amorco CA 22 mi50 min W 9.9 G 19 61°F 68°F1015 hPa60°F
RTYC1 - 9414523 - Redwood City, CA 25 mi50 min W 5.1 G 7 62°F 72°F1014.6 hPa
PCOC1 - 9415144 - Port Chicago, CA 26 mi50 min WSW 17 G 19 61°F 69°F1014.4 hPa
PRYC1 - 9415020 - Point Reyes, CA 31 mi50 min ESE 7 G 9.9 62°F 58°F1014.8 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 33 mi50 min WNW 14 G 19 62°F 1013.6 hPa
SFXC1 - San Francisco Bay Reserve, CA 34 mi113 min WNW 11 60°F 1014 hPa58°F
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 40 mi48 min S 5.8 G 9.7 60°F 61°F7 ft1014.7 hPa (-0.3)

Wind History for San Francisco, CA
(wind in knots)    EDIT      (on/off)   Help
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Francisco, San Francisco International Airport, CA15 mi1.7 hrsW 510.00 miA Few Clouds60°F54°F80%1015 hPa
Oakland, Metro Oakland International Airport, CA15 mi45 minN 610.00 miOvercast61°F59°F93%1015 hPa
Hayward, Hayward Air Terminal, CA21 mi44 minNNW 310.00 miOvercast63°F55°F76%1015.8 hPa
Half Moon Bay Airport, CA22 mi43 minSSE 610.00 miOvercast59°F55°F88%1014.6 hPa
Novato / Gnoss Field, CA23 mi63 minN 010.00 miOvercast61°F57°F88%1015.2 hPa
San Carlos Airport, CA23 mi48 minWNW 410.00 miOvercast63°F55°F77%1015.2 hPa
Concord, Buchanan Field, CA23 mi45 minW 610.00 miFair62°F57°F84%1013.4 hPa

Wind History from SFO (wind in knots)
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Last 24hrCalmCalmSE3SE3CalmSE7N6N8N86NW13
G19
W13NW14NW13NW14NW10W9NW7NW5NW6NW4W4W5S3
1 day agoSW9SW7S5S7SW8SW15SW11SW16SW14
G24
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W15W13W11SW6SW11W11SW66S4S4
2 days agoW12W11W13W10SW11W12SW10
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Tide / Current Tables for Alcatraz Island, San Francisco Bay, California
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Alcatraz Island
Click for Map
Thu -- 02:07 AM PDT     Moonrise
Thu -- 02:42 AM PDT     0.07 feet Low Tide
Thu -- 06:27 AM PDT     Sunrise
Thu -- 09:48 AM PDT     4.50 feet High Tide
Thu -- 02:24 PM PDT     2.58 feet Low Tide
Thu -- 04:45 PM PDT     Moonset
Thu -- 07:59 PM PDT     Sunset
Thu -- 08:41 PM PDT     6.50 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
20.90.20.10.51.122.93.84.44.54.23.632.62.73.244.95.86.46.564.9

Tide / Current Tables for Alcatraz Island W, San Francisco Bay, California Current
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Alcatraz Island W
Click for Map
Thu -- 12:16 AM PDT     -2.59 knots Max Ebb
Thu -- 02:07 AM PDT     Moonrise
Thu -- 04:09 AM PDT     0.01 knots Slack
Thu -- 06:27 AM PDT     Sunrise
Thu -- 07:18 AM PDT     2.54 knots Max Flood
Thu -- 10:50 AM PDT     -0.00 knots Slack
Thu -- 12:56 PM PDT     -1.22 knots Max Ebb
Thu -- 03:58 PM PDT     0.00 knots Slack
Thu -- 04:45 PM PDT     Moonset
Thu -- 06:57 PM PDT     2.08 knots Max Flood
Thu -- 07:59 PM PDT     Sunset
Thu -- 10:07 PM PDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-2.6-2.4-1.9-1.2-0.21.12.12.52.421-0.2-1-1.2-1-0.6011.82.11.81.20.2-1.1

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 (7,2,3,4)
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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.