Sunday, August20, 2017 L-36.com


Marine Weather and Tides
Half Moon Bay, 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 6:29AMSunset 7:55PM Sunday August 20, 2017 12:51 AM PDT (07:51 UTC) Moonrise 4:15AMMoonset 6:23PM Illumination 4% Phase: Waning Crescent; Moon at 28 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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PZZ545 Point Reyes To Pigeon Point To 10 Nm- 846 Pm Pdt Sat Aug 19 2017
Tonight..S winds 5 to 15 kt. Wind waves 1 to 3 ft. Mixed swell nw 3 to 5 ft at 10 seconds and S 3 ft at 15 seconds. Patchy fog after midnight.
Sun..S winds 10 to 20 kt. Wind waves 2 to 4 ft. NW swell 4 to 6 ft at 10 seconds. Patchy fog in the morning.
Sun night..SW winds 10 kt. Wind waves 2 ft or less. NW swell 4 to 6 ft at 10 seconds. Patchy fog after midnight.
Mon..SW winds 10 kt. Wind waves 2 ft or less. NW swell 3 to 5 ft at 10 seconds. Patchy fog in the morning.
Mon night..W winds 10 kt. Wind waves 2 ft or less. NW swell 3 to 5 ft at 9 seconds. Patchy fog after midnight.
Tue..W winds 10 kt. Wind waves 2 ft or less. NW swell 2 to 4 ft. SWell S 3 ft. Patchy fog.
Wed..W winds 10 to 20 kt. Wind waves 2 to 4 ft. Mixed swell nw 2 to 4 ft and S 3 ft.
Thu..NW winds 20 to 30 kt. Wind waves 3 to 5 ft. NW swell 4 to 6 ft. SWell sw 3 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 4 to 5 ft with a dominant swell period of 10 seconds. Across the bar...combined seas 4 to 6 ft with a dominant swell period of 10 seconds. Maximum ebb current of 1.9 knots at 02:00 am Sunday and 1.1 knots at 03:18 pm Sunday.
PZZ500 846 Pm Pdt Sat Aug 19 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Moderate northwest winds will continue across the northern outer waters tonight as high pressure builds in from the west. Winds are forecast to decrease below small craft advisory criteria by Sunday evening. In addition to breezy winds, locally steep wind waves will also continue tonight and into Sunday.

7 Day Forecast for Marine Location Near Half Moon Bay, CA
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location: 37.47, -122.48     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 200529
afdmtr
area forecast discussion
national weather service san francisco bay area
1029 pm pdt Sat aug 19 2017

Synopsis A few degrees of cooling are expected over the
weekend and into early next week as an approaching trough of low
pressure weakens the area of high pressure currently over the
eastern pacific. Coastal areas will see little in the way of
change with continue night and morning low clouds and patchy fog.

Discussion As of 7:50 pm pdt Saturday... An upper level trough
will continue to move in from the northwest and merge with another
nearly stationary low located along the central coast. Highs today
were fairly comfortable most places with only far inland locations
experiencing warm to hot temperatures as a ridge continues to be
replaced by an upper level trough. Northerly flow continues to
bring wildfire smoke in from the north and marine based clouds and
fog are widespread over the coastal waters. Onshore winds will
usher low clouds and fog inland each night and morning this week.

Cloud coverage Monday morning will be challenging to predict much
depending upon the depth and strength of the marine layer, though
of course, the farther inland one is the better chances there are
for clear skies. Some high clouds may also be over the area during
the solar eclipse. Going forecast looks good, for additional details
please see the previous discussion.

Prev discussion As of 1:25 pm pdt Saturday... Today's stratus has
been a bit slower to mix out compared to yesterday. Visible
satellite shows clouds along entire coastline from sonoma county
south through monterey county, and even some clouds pushing
through the golden gate east into berkeley. For the next several
hours, we have one of the two goes-16 mesoscale sectors over parts
of the pacnw with its southern extent covering the san francisco
bay area. With this mesoscale sector, we are able to get detailed
satellite imagery once every minute. It's fascinating to watch
this minute-by-minute data with the clouds gradually mixing out
over the bay combined with the continued push through the golden
gate gap. Check out @nwsbayarea on twitter to see it for yourself!
synoptically-speaking an upper level low is centered just over a
hundred miles offshore from los angeles. This low will help to
enhance potential thunderstorm activity over the next few days for
parts of southern california as well as the sierra nevada. For us
along the central coast and for the san francisco bay area, we're
a bit too far north to expect any sort of convective activity.

Nonetheless, the low is close enough to bring a gradual cooling
trend across interior areas of the san francisco bay area, san
benito county, and interior monterey county through the weekend.

This checks out for today as temperatures for most airports in the
area are running a few degrees below what they were 24 hours ago.

When all is set and done this afternoon, expect highs to
generally reach the 60s along the coast and the middle 70s to low
90s for interior areas. Little change is expected for highs on
Sunday along the immediate coast, but an additional 2 to 5
degrees of cooling is likely inland. Minimal day-to-day changes
are anticipated for the entire area for much of next week.

The cloud cover forecast for Monday continues to be a bit of a
challenge. If conditions permit, a partial solar eclipse can be
viewed throughout california while the total eclipse can be viewed
north in oregon. Models remain in good agreement that the upper
level low will remain parked near point conception in southern
california. Current thinking is that there will be cloud cover
along the coast on Monday morning. The big questions are 1) how
far inland will these clouds be, and 2) will areas with morning
clouds clear early enough to see the eclipse? We cannot
confidently answer these questions quite yet. Another potential
outcome (not likely, but still possible) is that the upper low
could end up mixing out the marine layer, allowing for mostly
clear conditions for much of the area. We will continue to monitor
the marine layer's behavior over the next 48 hours to see how it
responds to this upper low. The marine layer depth has trended
upward from 1,200 ft to 2,000 ft over the past day. Climatologically-
speaking, the best locations in the bay area for clear skies on a
mid late august morning would be interior areas of the east bay
away from the coast, as well as the higher elevations in the santa
cruz mountains, north bay mountains, and diablo range. The
eclipse of the Sun will begin shortly after 9:00 am pdt for the
bay area with peak obscuration happening around 10:15 am pdt. Peak
obscuration of the Sun will range from 71 percent in monterey and
up to 78 percent in santa rosa.

Aviation As of 10:29 pm pdt Saturday... The marine layer depth
has ramped up to nearly 2500 feet per the fort ord profiler, and
coastal stratus is spreading into inland valleys. All terminals
are expected to see MVFR ifr CIGS tonight with late morning burn
off.

Vicinity of ksfo...VFR early, ifr CIGS expected by 08z with
clearing by 18z. Afternoon sea breeze winds up to 15 kts expected.

Sfo bridge approach... Similar to sfo.

Monterey bay terminals... MVFR CIGS becoming ifr CIGS by 09z.

Clearing after 18z.

Marine As of 10:24 pm pdt Saturday... Moderate northwest winds
will continue across the northern outer waters tonight as high
pressure builds in from the west. Winds are forecast to decrease
below small craft advisory criteria by Sunday evening. In
addition to breezy winds, locally steep wind waves will also
continue tonight and into Sunday.

Mtr watches warnings advisories
Tngt Sca... Pt arena to pigeon pt 10-60 nm
public forecast: canepa
aviation: sims
marine: sims
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 14 mi52 min S 6 G 7 64°F 73°F1011 hPa (+0.0)
PXOC1 - 9414311 - San Francisco (Pier 1), CA 23 mi58 min W 2.9 G 9.9 60°F 1010.7 hPa
FTPC1 - 9414290 - San Francisco, CA 23 mi52 min WSW 6 G 12 58°F 60°F1012.2 hPa (+0.0)
AAMC1 - 9414750 - Alameda, CA 23 mi52 min W 6 G 8.9 61°F 68°F1012.2 hPa (+0.0)
46237 - San Francisco Bar, CA (142) 23 mi52 min 60°F5 ft
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 23 mi62 min WSW 1.9 G 7.8 59°F 62°F8 ft1012 hPa (+0.0)
PXSC1 23 mi52 min 61°F 58°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi52 min WSW 14 G 16
OBXC1 24 mi52 min 61°F 58°F
LNDC1 25 mi52 min W 8 G 12 61°F 1011.7 hPa (+0.0)
OKXC1 - 9414776 - Oakland (Berth 34), CA 25 mi52 min WSW 6 G 13 61°F 1011.7 hPa (+0.0)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi62 min SSW 5.8 G 7.8 57°F 59°F5 ft1012.2 hPa (+0.0)
TIBC1 - Tiburon Pier, San Francisco Bay, CA 29 mi60 min NNE 6 59°F 1012 hPa (+0.0)
PPXC1 - 9414847 - Richmond (Point Potrero), CA 31 mi52 min SW 18 G 22 61°F 1011.6 hPa (+0.0)
RCMC1 - 9414863 - Richmond, CA 32 mi52 min SSW 9.9 G 15 60°F 65°F1011.4 hPa (+0.0)
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 42 mi52 min WSW 12 G 16 61°F 1010.9 hPa (+0.0)
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi52 min WSW 8.9 G 13 61°F 69°F1011.2 hPa (+0.0)59°F
PRYC1 - 9415020 - Point Reyes, CA 45 mi52 min SE 4.1 G 7 60°F 60°F1011.5 hPa (+0.0)
PCOC1 - 9415144 - Port Chicago, CA 47 mi52 min WSW 19 G 22 61°F 69°F1010.4 hPa (+0.0)
46042 - MONTEREY - 27NM West of Monterey Bay, CA 48 mi62 min SW 1.9 G 1.9 61°F 61°F6 ft1012.9 hPa (+0.4)

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA3 mi57 minS 89.00 miOvercast59°F57°F94%1011.8 hPa
San Francisco, San Francisco International Airport, CA12 mi1.9 hrsS 610.00 miA Few Clouds66°F55°F68%1011.4 hPa
San Carlos Airport, CA13 mi62 minN 010.00 miPartly Cloudy63°F57°F83%1011.8 hPa
Palo Alto Airport, CA19 mi4.1 hrsN 1210.00 miClear64°F59°F83%1011.5 hPa
Oakland, Metro Oakland International Airport, CA21 mi59 minWNW 310.00 miPartly Cloudy60°F57°F93%1011.6 hPa
Mountain View, Moffett Field, CA23 mi56 minENE 410.00 miFair63°F59°F87%1012 hPa
Hayward, Hayward Air Terminal, CA23 mi58 minW 710.00 miMostly Cloudy63°F55°F76%1012.4 hPa

Wind History from HAF (wind in knots)
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Last 24hrSE5S6S6S5SE5S7SE8SE6S8S8S8S8S8S6S7S7S7S6S5S6S6S7S9S9
1 day agoCalmSW4CalmW3CalmCalmCalmCalmSW4SW6W6W6SW7SW6SW8SW6SW5S6S7SE4S5S5S5S5
2 days agoS9S9S6S6S6--SW3S5S6S7S7S7S7SW7S6SW5W5--CalmCalmNE3CalmCalmCalm

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
Click for Map
Sun -- 04:11 AM PDT     -0.74 feet Low Tide
Sun -- 05:15 AM PDT     Moonrise
Sun -- 06:30 AM PDT     Sunrise
Sun -- 10:58 AM PDT     5.10 feet High Tide
Sun -- 04:08 PM PDT     2.06 feet Low Tide
Sun -- 07:23 PM PDT     Moonset
Sun -- 07:55 PM PDT     Sunset
Sun -- 10:07 PM PDT     6.48 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
42.40.8-0.3-0.7-0.50.21.32.63.84.85.14.843.12.42.12.334.15.26.16.56.2

Tide / Current Tables for San Mateo Bridge, South San Francisco Bay, California Current
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San Mateo Bridge
Click for Map
Sun -- 12:15 AM PDT     -0.00 knots Slack
Sun -- 03:51 AM PDT     -2.10 knots Max Ebb
Sun -- 05:13 AM PDT     Moonrise
Sun -- 06:29 AM PDT     Sunrise
Sun -- 07:16 AM PDT     0.00 knots Slack
Sun -- 10:12 AM PDT     2.16 knots Max Flood
Sun -- 01:39 PM PDT     -0.01 knots Slack
Sun -- 04:29 PM PDT     -1.21 knots Max Ebb
Sun -- 07:16 PM PDT     0.01 knots Slack
Sun -- 07:22 PM PDT     Moonset
Sun -- 07:54 PM PDT     Sunset
Sun -- 09:59 PM PDT     1.76 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.3-0.6-1.4-2-2.1-1.8-1.2-0.30.91.82.221.50.7-0.3-0.9-1.2-1.2-0.8-0.20.71.51.81.6

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 (3,6,7,8)
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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.