Monday, May21, 2018 L-36.com


Marine Weather and Tides
Muir Beach, 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 5:53AMSunset 8:19PM Monday May 21, 2018 8:00 AM PDT (15:00 UTC) Moonrise 11:24AMMoonset 12:35AM Illumination 42% Phase: First Quarter Moon; Moon at 7 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- 237 Am Pdt Mon May 21 2018
.small craft advisory in effect through late tonight...
Today..NW winds 15 to 25 kt. Wind waves 4 to 6 ft. W swell 2 to 4 ft at 11 seconds.
Tonight..NW winds 15 to 25 kt. Wind waves 4 to 6 ft. W swell 4 to 5 ft at 10 seconds and sw 3 ft at 21 seconds.
Tue..W winds 10 to 20 kt. Wind waves 2 to 4 ft. W swell 4 to 5 ft at 10 seconds and sw 3 ft at 19 seconds.
Tue night..W winds 5 to 15 kt. Wind waves 1 to 3 ft. W swell 3 to 5 ft at 10 seconds and sw 3 ft at 19 seconds.
Wed..W winds 5 to 15 kt. Wind waves 1 to 3 ft. Mixed swell nw 3 to 4 ft at 10 seconds and sw 3 to 4 ft at 17 seconds.
Thu..SW winds 10 kt. Wind waves 2 ft or less. W swell 3 to 5 ft and sw 3 to 4 ft.
Fri..SW winds 10 kt. Wind waves 2 ft or less. W swell 2 to 4 ft and sw 3 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 5 to 7 ft with a dominant period of 10 seconds. Across the bar...combined seas 6 to 8 ft with a dominant period of 10 seconds. Maximum ebb current of 3 knots at 08:07 am Monday and 1.6 knots at 10:19 pm Monday.
PZZ500 237 Am Pdt Mon May 21 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Strong and gusty northwesterly winds will begin to decrease late tonight as high pressure over the eastern pacific weakens. Thus, steep, short period wind waves will continue to make seas rough and hazardous today, especially for small crafts. Winds will become light to moderate by Tuesday, persisting through the remainder of the week. Long period southwesterly swell will mix with northwesterly swell later this morning and will continue into Wednesday.

7 Day Forecast for Marine Location Near Muir Beach, CA
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location: 37.78, -122.67     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 211156
afdmtr
area forecast discussion
national weather service san francisco bay area
456 am pdt Mon may 21 2018

Synopsis Below normal temperatures will continue as an upper
level low moving across the state maintains a moderately strong
gradient resulting in brisk onshore flow across the region and a
deep marine layer. Another upper level low will approach the
later half of the week and into the weekend with onshore winds
keeping temperatures on the cool side of normal while mainly dry
conditions persist.

Discussion As of 3:25 am pdt Monday... Nighttime optics reveal
widespread low clouds across much of the district from the san
francisco san mateo county line south. Meanwhile areas to the
north remain relatively clear with the exception of a couple of
patches over portions of napa and marin. Latest observations show
cloud decks around 1500 feet. A distinct difference from yesterday
is the gradients. As the low digs farther south the northerly
gradient has strengthened while the westerly gradient has
weakened. Acv to sfo (northerly gradient) strengthened from 3.2 mb
to 5 mb over the last 24 hours. While sfo to wmc (westerly
gradient) weakened from 5.2 mb to 2.1 mb during the same time.

This and the cyclonic flow associated with the upper low currently
centered near fresno are the reasons why the northern half of the
forecast area remains clear at this hour.

Temperatures at this hour are running in the low to mid 50s, within
a degree or 2 of temperatures at this time yesterday. While
temperatures are forecast to be slightly warmer than yesterdays
highs, temperatures will remain below normal for this time of
year. Warmest temperatures are expected over the north bay today
and Tuesday as a result of the stronger northerly flow that has
all but cleared out the low clouds and will allow for abundant
sunshine. Santa rose is forecast to reach 79 degrees today with
mid 80s possible over the warmest inland north bay locations. With
another upper low on the heels of the low mentioned above there
will be little chance of a warm up. The approaching low will
maintain cool temperatures across the region as it once again
strengthens the onshore gradient and deepens the marine layer
allowing widespread penetration of the cool marine air and low
clouds.

Coastal drizzle remains possible this morning mainly for portions
of the san mateo, santa cruz and monterey county coastlines. The
nam and WRF continue to show localized light precipitation along
the immediate coast.

The next upper level low is forecast to arrive Thursday night
into Friday. Anticipate onshore flow to strengthen and daytime
highs to remain below normal. Models continue to fine tune their
solutions with respect to timing as well as the possibility of
precipitation over the area. Will hold off on making any changes
as we are still far enough out. Models do indicate however that
this system will kick out of the region by Sunday and high
pressure will begin building back in. Warmer temperatures appear
to be on tap for at least the second half of the holiday weekend.

Aviation As of 4:56 am pdt Monday... For 12z tafs. A very
erratic stratus deck in place across the bay area this morning.

Generally MVFR CIGS at all but north bay terminals at this hour.

Anticipate this ill defined pseudo marine layer to mix out
earlier today than it did yesterday, except for terminals along
the immediate coast, such as kmry. Onshore winds will continue
through the day, less windy gusty than yesterday. Stratus will
return again this evening.

Vicinity of ksfo... Currently MVFR CIGS affecting the terminal.

However, latest fog product satellite shows a hole in the stratus
over the bridge approach. A little tough to know how this will
affect the terminal and clearing time. TAF may have to be amended
if this hole spreads northward. Breezy, occasionally gusty,
onshore winds this afternoon, not as breezy as previous days.

Stratus expected to return again early this evening.

Sfo bridge approach... Hole in the stratus is resulting in clr
conditions, per latest smb ob. However, intermittent MVFR CIGS may
affect bridge approach through 18-19z.

Monterey bay terminals... Another day where MVFR CIGS are possible
through the TAF period, specifically at kmry. Partial clearing
may occur late this morning early afternoon at ksns. Light to
moderate westerly winds, occasionally gusty, by afternoon. Low
clouds return by late afternoon or early evening.

Marine As of 2:43 am pdt Monday... Strong and gusty
northwesterly winds will begin to decrease late tonight as high
pressure over the eastern pacific weakens. Thus, steep, short
period wind waves will continue to make seas rough and hazardous
today, especially for small crafts. Winds will become light to
moderate by Tuesday, persisting through the remainder of the week.

Long period southwesterly swell will mix with northwesterly swell
later this morning and will continue into Wednesday.

Mtr watches warnings advisories
Tday Sca... Mry bay from 10 am
sca... Pigeon pt to pt pinos 0-10 nm from 10 am
sca... Pt arena to pt reyes 0-10 nm
sca... Pt arena to pigeon pt 10-60 nm
sca... Pt reyes to pigeon pt 0-10 nm
sca... Pt pinos to pt piedras blancas 0-10 nm
sca... Pigeon pt to pt piedras blancas 10-60 nm
sca... Sf bay from 3 pm
public forecast: cw
aviation: bam
marine: bam
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
46237 - San Francisco Bar, CA (142) 2 mi61 min 50°F6 ft
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 9 mi51 min NNW 9.7 G 14 51°F 51°F1012 hPa51°F
FTPC1 - 9414290 - San Francisco, CA 11 mi49 min S 2.9 G 4.1 52°F 55°F1011.8 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 14 mi146 min S 2.9 52°F 1011 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 15 mi49 min ESE 2.9 G 4.1 54°F 1010.4 hPa
PXSC1 15 mi49 min 55°F 50°F
RCMC1 - 9414863 - Richmond, CA 17 mi49 min S 5.1 G 7 54°F 58°F1011.2 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 18 mi49 min S 2.9 G 6
PPXC1 - 9414847 - Richmond (Point Potrero), CA 18 mi43 min S 8 G 8.9 1011.7 hPa
OBXC1 18 mi43 min 54°F 52°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 18 mi43 min SSW 5.1 G 8 54°F 1011.6 hPa
AAMC1 - 9414750 - Alameda, CA 20 mi49 min SSW 4.1 G 6 53°F 62°F1011.7 hPa
LNDC1 21 mi43 min S 5.1 G 6 55°F 1011.5 hPa
PRYC1 - 9415020 - Point Reyes, CA 22 mi49 min WNW 14 G 20 51°F1010.8 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 29 mi43 min SW 6 G 8 1010.9 hPa
RTYC1 - 9414523 - Redwood City, CA 31 mi43 min 64°F
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 31 mi71 min NW 19 G 25 53°F 53°F10 ft1011.2 hPa (-0.0)
MZXC1 - 9415102 - Martinez-Amorco CA 34 mi43 min 64°F
PCOC1 - 9415144 - Port Chicago, CA 38 mi49 min SW 7 G 11 54°F 63°F1010.7 hPa
46214 - Point Reyes, CA (029) 44 mi61 min 52°F12 ft
SFXC1 - San Francisco Bay Reserve, CA 45 mi76 min WNW 6 52°F 1010 hPa51°F
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 45 mi43 min WNW 6 G 11 1010.1 hPa
46013 - Bodega Bay - 48NM North Northwest of San Francisco, CA 46 mi51 min NW 25 G 31 52°F 1011.5 hPa50°F

Wind History for San Francisco, CA
(wind in knots)    EDIT      (on/off)   Help
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G22
W11
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W11
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G15
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W9
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SW6
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Francisco, San Francisco International Airport, CA20 mi65 minS 310.00 miPartly Cloudy54°F46°F77%1011.3 hPa
Half Moon Bay Airport, CA21 mi66 minSSE 34.00 miFog/Mist50°F48°F94%1011.8 hPa
Oakland, Metro Oakland International Airport, CA24 mi68 minSSW 57.00 miA Few Clouds53°F48°F86%1011.4 hPa

Wind History from SFO (wind in knots)
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W17W15W10SW7S4W4SW3S3
1 day agoW9
G19
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2 days agoW8W10W12W12SW10W10W15W17W20W19
G26
W18W17
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W15
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W9
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W12W11W16W12
G19
W10W14
G23
W15
G21
W13
G19
W17
G22
4
G19

Tide / Current Tables for San Francisco Bar, California
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San Francisco Bar
Click for Map
Mon -- 01:34 AM PDT     Moonset
Mon -- 04:01 AM PDT     4.99 feet High Tide
Mon -- 05:56 AM PDT     Sunrise
Mon -- 10:52 AM PDT     -0.60 feet Low Tide
Mon -- 12:24 PM PDT     Moonrise
Mon -- 06:19 PM PDT     4.91 feet High Tide
Mon -- 08:18 PM PDT     Sunset
Mon -- 08:50 PM PDT     First Quarter
Mon -- 11:47 PM PDT     2.33 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
33.64.24.854.842.81.50.3-0.4-0.6-0.30.41.42.53.64.54.94.84.33.62.92.4

Tide / Current Tables for South Channel, San Francisco Bay Approach, California Current
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South Channel
Click for Map
Mon -- 01:34 AM PDT     Moonset
Mon -- 02:18 AM PDT     0.78 knots Max Flood
Mon -- 05:24 AM PDT     -0.01 knots Slack
Mon -- 05:55 AM PDT     Sunrise
Mon -- 08:37 AM PDT     -1.63 knots Max Ebb
Mon -- 12:20 PM PDT     0.01 knots Slack
Mon -- 12:23 PM PDT     Moonrise
Mon -- 03:34 PM PDT     1.37 knots Max Flood
Mon -- 07:21 PM PDT     -0.00 knots Slack
Mon -- 08:18 PM PDT     Sunset
Mon -- 08:50 PM PDT     First Quarter
Mon -- 09:38 PM PDT     -0.91 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.10.50.80.70.50.2-0.4-1.1-1.5-1.6-1.3-0.8-0.20.411.31.41.20.80.2-0.4-0.8-0.9-0.7

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 (11,2,3,4)
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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.