Saturday, December15, 2018 L-36.com


Marine Weather and Tides
Moss Beach, CA

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 7:16AMSunset 4:54PM Saturday December 15, 2018 3:44 PM PST (23:44 UTC) Moonrise 12:48PMMoonset 12:00AM Illumination 59% Phase: Waxing Gibbous; Moon at 8 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 Coastal Waters From Point Reyes To Pigeon Point California Out To 10 Nm- 158 Pm Pst Sat Dec 15 2018
.small craft advisory for rough bar in effect through late tonight...
.small craft advisory in effect from Sunday morning through Sunday afternoon...
Tonight..SE winds 15 to 20 kt...becoming S 15 to 25 kt after midnight. Wind waves 3 to 4 ft...building to 4 to 6 ft after midnight. W swell 5 to 9 ft at 13 seconds. A chance of showers this evening, then rain after midnight.
Sun..S winds 20 to 30 kt. Wind waves 6 to 9 ft. W swell 5 to 10 ft at 16 seconds. Rain.
Sun night..W winds 15 to 25 kt with gusts up to 30 kt. Wind waves 4 to 6 ft. W swell 14 to 19 ft at 21 seconds. Showers and a slight chance of Thunderstorms.
Mon..W winds 5 to 10 kt. Wind waves 2 ft or less. W swell 16 to 21 ft at 21 seconds. A slight chance of showers.
Mon night..W winds around 5 kt. Wind waves 2 ft or less. W swell 13 to 18 ft at 18 seconds.
Tue..S winds 5 to 10 kt. Wind waves 2 ft or less. W swell 10 to 13 ft.
Tue night..SW winds around 5 kt. Wind waves 2 ft or less. W swell 9 to 13 ft.
Wed..NE winds around 5 kt. Wind waves 2 ft or less. W swell 11 to 16 ft.
Thu..NW winds around 5 kt. Wind waves 2 ft or less. W swell 8 to 11 ft. Winds and wind waves higher in and near Thunderstorms.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 10 to 12 ft with a dominant period of 15 seconds. Across the bar...combined seas 13 to 15 ft with locally larger breaking waves. A dominant period of 15 seconds. Maximum ebb current of 1.5 knots at 10:37 pm Saturday and 1.8 knots at 11:43 am Sunday.
PZZ500 158 Pm Pst Sat Dec 15 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... A moderate west to northwest swell will build and result in hazardous sea conditions through this evening. South to southeasterly winds will increase overnight ahead of a pacific storm system that will bring widespread rain and the potential for Thunderstorms. An even larger, more powerful long period west to northwest swell, the largest so far this season, will impact the coastal waters Sunday afternoon through Monday.


7 Day Forecast for Marine Location Near Moss Beach CDP, CA
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location: 37.51, -122.56     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 152208
afdmtr
area forecast discussion
national weather service san francisco bay area
208 pm pst Sat dec 15 2018

Synopsis A weak frontal system will remain over the north bay
today, producing scattered light showers. A stronger and wetter
system is forecast to impact the entire region Sunday and Sunday
night, with widespread moderate rain. Brief heavy rain is
possible Sunday afternoon and evening. In addition, gusty south
winds are likely Sunday and Sunday evening, mainly near the coast
and in the hills. Showers will taper off by late Sunday night and
end by midday Monday. A very large wave train arrives late Sunday
into Monday. Dry and mild weather is forecast from Monday
afternoon through much of next week.

Discussion As of 02:08 pm pst Saturday... Satellite imagery
reveals the synoptic pattern, with a large, deep trough centered
at about 50n 145w, providing us with high clouds streaming
overhead. This trough has plenty of cold air at its core with a
large area of convective clouds behind a cold front. Warm
advection continues in our region with winds veering with height.

A front which stalled over the bay area last night has lifted into
the north bay, where scattered showers continue to produce light
rainfall amounts. These showers have slowly drifted to the
northwest and measurable rainfall in the past hour was confined to
the northwestern portion of sonoma county. Showers will continue
to decrease this afternoon but will increase late this evening
across the north bay as the deep upper level trough approaches.

Temperatures today have generally warmed into the upper 50s to mid
60s, with the warmest locations in the south bay.

The upper trough off the coast will be our main weather maker for
the region Saturday night through Monday. As the trough
approaches, prefrontal warm advection precipitation, aided by
orographic lifting, will increase across the north bay late
tonight through Sunday morning. A potent cold front will approach
the north bay by late afternoon Sunday, pushing southeast and
reaching the sf bay by mid evening and the monterey bay by early
Monday morning. A region of high pwat (1.1-1.3") will push
through ahead of the cold front. Combined with strong
southwesterly flow, integrated vapor transport will rise into the
500-700 kg m S range, categorizing this event as a moderate
strength atmospheric river. Rain will intensify along and just
ahead of the cold front, with a brief period of heavy rain likely
along the front. Winds at the surface will become breezy to gusty
out of the south ahead of the front, especially along the coast
and in the higher terrain, but are not expected to reach advisory
criteria. As the front moves through, winds will quickly decrease
in strength and precipitation will taper off. The front and
precipitation are expected to be exiting monterey and san benito
counties early Monday morning, with drying behind the front. Rainfall
totals will range from 1-3 inches across the north bay and
coastal mountains and 0.5 to 1.25 inches in the populated areas
from the golden gate south. Some of the higher terrain of the
north bay could see locally greater than 3 inches as moderate rain
falls most of the day Sunday. Finally, isolated thunderstorms are
possible along and behind the cold front as cooler air aloft
moves in with the trough creating instability.

Additionally, this system will be accompanied by a powerful swell
and large breaking waves Sunday through late Monday. This could
lead to minor coastal flooding in susceptible areas. See the
beaches section below for more details on the large impacts
expected along our coastline.

Following the trough, precipitation will end across all areas by
Monday afternoon. A ridge will then try to build into the region
starting Monday night. A plume of high pwat will push to our
north into far northern ca and or, but may sag just far enough
south for some light showers across our northern areas Tuesday and
Wednesday. 850 mb temps will warm to 12-14c on Wednesday and
Thursday under the ridge, and highs will respond by warming into
the low 60s to near 70 areawide. Lows will cool slightly as
conditions dry out, but should remain in the 40s to low 50s. A
system approaches the area on Thursday night and Friday, but looks
to fall apart as it does and precipitation chances remain low.

Temperatures will cool slightly but will remain mild through the
period.

Aviation As of 09:45 am pst Saturday... MainlyVFR conditions
persist over the terminals today excepted for ksts where low
clouds, rain and reduced visibility will persist in response to a
stalled frontal boundary. Southerly winds will generally be light
yet may increase a bit this afternoon through early evening.

Conditions will worsen region-wide during the day Sunday first
over the san francisco bay area as a more potent frontal system
approaches the region.

Vicinity of ksfo...VFR conditions likely through the day. South-
southeasterly winds will increase to around 10 knots after 21z.

Winds diminish slightly overnight but increase again and become
gusty Sunday morning ahead of the approaching cold front. More
widespread rain expected by midday Sunday.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR. Southeasterly winds, increasing a
bit late this morning and into the afternoon in the northern
salinas valley. Winds briefly turn onshore this afternoon before
becoming southeasterly again tonight and into Sunday morning.

Beaches As of 09:45 am pst Saturday... A potent storm system
has resulted in a very large, long period west to northwest swell
train aimed at the california coast. Very long period forerunners
will arrive Sunday morning bringing a significantly increased risk
of rip currents and sneakers waves to the coast. The largest
waves are then forecast to arrive Sunday night through Monday
morning, with peak swells of 17 to 21 ft at 19 to 21 seconds.

Large breaking waves of 25 to 40 ft will be possible at west and
northwest facing locations, with breakers up to or exceeding 50 ft
at favored break points along the coast. A high surf warning
remains in effect from 9 am Sunday through 9 pm Monday along the
entire coastline.

Marine As of 09:45 am pst Saturday... A moderate west to
northwest swell will build and result in hazardous sea conditions
through the day. South to southeasterly winds will increase
tonight into Sunday morning ahead of a pacific storm system that
will bring widespread rain and the potential for thunderstorms. An
even larger, more powerful long period west to northwest swell,
the largest seen this season so far, will move in Sunday afternoon
through Monday.

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... Rough bar advisory for sf bar
public forecast: st
aviation: rgass
marine: rgass
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 18 mi62 min NW 2.9 G 4.1 62°F 55°F1017.3 hPa
46237 - San Francisco Bar, CA (142) 19 mi74 min 56°F9 ft
FTPC1 - 9414290 - San Francisco, CA 21 mi62 min NNW 4.1 G 5.1 60°F 56°F1017.1 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 22 mi44 min SSE 16 G 21 58°F 57°F1017.1 hPa (-1.5)
PXOC1 - 9414311 - San Francisco (Pier 1), CA 22 mi56 min SE 4.1 G 8 60°F 1015.8 hPa
PXSC1 22 mi62 min 62°F 51°F
AAMC1 - 9414750 - Alameda, CA 23 mi62 min SSW 1.9 G 1.9 58°F 55°F1017.3 hPa
OBXC1 23 mi62 min 58°F 52°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi62 min S 2.9 G 5.1
OKXC1 - 9414776 - Oakland (Berth 34), CA 24 mi62 min S 4.1 G 5.1 58°F 1016.9 hPa
LNDC1 25 mi62 min S 2.9 G 4.1 58°F 1016.9 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 27 mi63 min NNW 2.9 56°F 1017 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 29 mi56 min ESE 1.9 G 2.9 59°F 1017.3 hPa
RCMC1 - 9414863 - Richmond, CA 30 mi56 min 56°F
PRYC1 - 9415020 - Point Reyes, CA 40 mi62 min 56°F1016.5 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 41 mi56 min E 8.9 G 11 56°F 1016.7 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi62 min NE 6 G 7 54°F 54°F1017.4 hPa54°F
PCOC1 - 9415144 - Port Chicago, CA 47 mi62 min NE 8 G 8.9 54°F 53°F1017.4 hPa

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA3 mi49 minSSW 16 G 214.00 miOvercast with Haze59°F51°F77%1016.9 hPa
San Francisco, San Francisco International Airport, CA13 mi48 minN 010.00 miMostly Cloudy61°F50°F67%1016.5 hPa
San Carlos Airport, CA16 mi57 minN 310.00 miMostly Cloudy63°F51°F68%1016.9 hPa
Oakland, Metro Oakland International Airport, CA22 mi51 minW 310.00 miOvercast60°F51°F72%1017.2 hPa
Palo Alto Airport, CA23 mi57 minE 510.00 miMostly Cloudy64°F50°F60%1016.9 hPa

Wind History from SFO (wind in knots)
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E3S12S10CalmS12SW7SE5SE6SE5SE5E3SE8SE6E4SE5SE5E5E8E5E4E5Calm
1 day agoN6NE7NE9CalmSE3CalmCalmCalmS3S3CalmCalmW3NE8NE8SE4E3E6E6S17
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2 days agoW10W11W10W8W11CalmCalmS4CalmCalmCalmCalmCalmS3S3S3S3NE7E3CalmCalmCalmE4NE4

Tide / Current Tables for Princeton, Half Moon 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 Sierra Point 1.3 mi ENE, South San Francisco Bay, California Current
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Sierra Point 1.3 mi ENE
Click for Map
Sat -- 12:02 AM PST     0.00 knots Slack
Sat -- 03:18 AM PST     0.81 knots Max Flood
Sat -- 03:49 AM PST     First Quarter
Sat -- 06:47 AM PST     -0.00 knots Slack
Sat -- 07:17 AM PST     Sunrise
Sat -- 09:32 AM PST     -0.73 knots Max Ebb
Sat -- 12:47 PM PST     Moonrise
Sat -- 01:05 PM PST     0.00 knots Slack
Sat -- 03:40 PM PST     0.48 knots Max Flood
Sat -- 04:51 PM PST     Sunset
Sat -- 06:33 PM PST     -0.00 knots Slack
Sat -- 09:38 PM PST     -0.82 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-00.30.70.80.80.60.3-0.1-0.5-0.7-0.7-0.5-0.3-00.30.40.50.40.2-0.2-0.5-0.8-0.8-0.6

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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Wind Forecast for San Francisco/Monterey Bay Area, CA (18,4,5,8)
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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.