Wednesday, October18, 2017 L-36.com


Marine Weather and Tides
Pacifica, 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 7:21AMSunset 6:28PM Wednesday October 18, 2017 9:53 AM PDT (16:53 UTC) Moonrise 5:09AMMoonset 5:19PM Illumination 3% 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- 905 Am Pdt Wed Oct 18 2017
Today..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 5 ft at 12 seconds and sw 3 ft at 16 seconds. Patchy fog late in the morning.
Tonight..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. NW swell 3 to 5 ft at 11 seconds and sw 3 ft at 16 seconds.
Thu..SW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft at 12 seconds and sw 3 ft at 15 seconds. Slight chance of rain in the afternoon.
Thu night..W winds 5 to 15 kt. Wind waves 1 to 3 ft. W swell 7 to 9 ft at 20 seconds and S 3 ft at 15 seconds. Chance of rain in the evening, then chance of showers after midnight.
Fri..NW winds 10 to 20 kt. Wind waves 2 to 4 ft. W swell 12 to 15 ft at 18 seconds.
Sat..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. W swell 8 to 10 ft.
Sun..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. W swell 7 to 9 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 3 to 5 ft with a dominant swell period 12 seconds. Across the bar...combined seas 4 to 6 ft with a dominant swell period of 12 seconds. Maximum ebb current of 1.6 knots at 03:12 pm Wednesday and 1.2 knots at 03:06 am Thursday.
PZZ500 905 Am Pdt Wed Oct 18 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Areas of fog this morning across the coastal waters and into the bays. Winds will increase over the bays this afternoon into tonight. A cold front will move across the waters late tomorrow bringing chances of light rain. A moderate to long period mixed northwesterly and southerly swell has arrived with buoys reporting periods of 17 to 18 seconds across the waters. Late Thursday into Friday a large northwesterly swell train will move across he area. This large swell will create hazardous conditions.

7 Day Forecast for Marine Location Near Pacifica, CA
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location: 37.62, -122.51     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 181615
afdmtr
area forecast discussion
national weather service san francisco bay area
915 am pdt Wed oct 18 2017

Synopsis Cooler temperatures are expected today and Thursday
as onshore flow strengthens. A weak early season weather system is
forecast to bring light rain to much of the region from Thursday
afternoon through Thursday night. Dry weather is expected to
return by Friday. A warming trend will begin over the weekend.

Warm and dry weather is expected regionwide early next week.

Discussion As of 09:07 am pdt Wednesday... In response to
increased onshore flow during the past 18 hours or so, the marine
layer has returned at a depth of around 500 feet. With this, low
clouds have also returned to the coast and have spread locally
inland to the valley locations. Patchy fog, dense at times, is
also impacting portions of the region this morning. Look for low
clouds and or patchy fog to persist through the morning before
burning off later as daytime heating takes place. With that said,
some coastal areas may remain under cloud cover through a good
portion of the day. Overall, temperatures today will be cooler
than those on Tuesday, yet should be at or slightly above seasonal
averages before a more significant cool down arrives Thursday
into Friday as a cold front pushes through the region. Only minor
updates have been made this morning to reflect current satellite
and temperature trends. Please see the forecast discussion below
for additional details.

Prev discussion As of 3:35 am pdt Wednesday... Kmux radar is still
showing some weak showers over extreme southern monterey county.

Nothing is being reported at automated gauges, so this is all
likely aloft. Meanwhile satellite imagery shows some high clouds
currently moving over the area with coastal stratus making a
resurgence and starting to spread locally inland over san
francisco as well as into the monterey bay and salinas valley.

Current temperature trends indicate cooler temperatures in most
locations with readings from the lower 40s to the mid 50s. Surface
pressure gradients are now stronger onshore with 1.3 mb from sfo
to sac compared to light offshore (-0.2 mb) yesterday at this
time. There is still a very weak offshore gradient component from
wmc to sfo at 2.2 mb, but this is decreasing.

Today is expected to be cooler across the district but mainly near
the coast as onshore flow ramps up with highs ranging from the
60s at the coast to the 70s and 80s inland. Additional cooling
will occur on Thursday, especially inland, as a weak storm system
approaches the coast and increases cloudiness. Latest models bring
light rain to the sonoma coast by Thursday afternoon, and then
spreads rain across most of the north bay by early evening. The
weakening frontal boundary will then press south of the golden
gate by late Thursday and bring scattered amounts of light rain to
the rest of the bay area Thursday evening and as far south as
monterey county by later Thursday night. The models continue to
trend drier with this system and a blend of recent model output
indicates most locations will pick up less than a tenth of an inch
on Thursday and Thursday night. Locally higher amounts of a
quarter to a third of an inch are possible across northwest sonoma
county. Nearly all models now indicate rain will end by daybreak
Friday.

A warming trend is forecast to begin during the weekend as an
upper level ridge begins to build over the west. The ridge will
then strengthen early next week and light offshore flow will
develop. This will result in warm and dry conditions throughout
the district next Monday and Tuesday with widespread highs in the
80s, even near the coast. The ridge is progged to flatten after
midweek.

Aviation As of 5:07 am pdt Wednesday... Profiler data shows the
marine layer is compressed down to 300 to 800 feet from bodega bay
to point sur, similarly the sodar at san carlos is showing a marine
layer temperature inversion based near 800 feet. Coverage of lifr vlifr
in fog has increased rapidly overnight across the coastal waters and
up to the immediate coastline and locally into the bays per satellite
imagery and METAR obs. ElsewhereVFR persists. Sufficient near surface
moisture continues to converge ahead of an elevated cool front approx
350-400 miles west of the bay area, and the front is forecast to proceed
toward the coast reaching the forecast area tonight. Patchy drizzle
is possible from sea ranch south to the san mateo coast to the monterey
peninsula tonight Thursday morning, additionally expect low CIGS in
stratus and fog. The latest NAM shows fairly rapid lower level cooling
tonight which should be enough to erode the marine inversions from
north-south tonight into Thursday. Winds will be onshore during the
period. All of this is in advance of the recently advertised (and
distinctly separate) cold frontal passage expected to arrive from
the gulf of alaska later Thursday.

Vicinity of ksfo... Slightly better than moderate confidenceVFR holds
this morning in the vicinity of the terminal. Westerly wind is near
10 knots, onshore winds increasing with gusts to 20 knots is forecast
this afternoon and evening.VFR in 12z TAF for the period, however cig
forecast confidence steadily lowers late today and tonight. If stratus
and or fog is able to reach ksfo greatly hinges on the marine layer
depth behavior later today tonight.

Sfo bridge approach... Update at 6:59 am: goes-16 shows a fairly rapid
expansion of fog and low clouds across the south bay this morning with
the northern extent reaching ksql and the san mateo bridge. Clearing
of clouds and fog 16z-17z.

Monterey bay terminals... Vlifr lifr this morning with partial clearing
by late morning, though timing is near low confidence. Ifr due to stratus
and fog are likely to return early this evening.

Fire weather As of 3:35 am pdt Wednesday... Relative humidity
values have been increasing in the valleys and along the lower
coastal slopes as light onshore flow begins to develop. However,
the airmass in the hills above 1000 feet remains relatively warm
and very dry. Poor humidity recoveries are occurring in the hills
this morning. Fortunately, winds will remain light. More
widespread cooling will take place today as onshore winds increase
in the afternoon. This will result in better humidity recoveries
tonight into Thursday morning and more significant cooling by
Thursday. A weak early season weather system is forecast to bring
light rain to the north bay from Thursday afternoon through
Thursday evening and to much of the rest of the district on
Thursday night. The models have been trending drier with this
system. Latest forecast rainfall amounts for Thursday and Thursday
night range from a tenth to a quarter of an inch across northwest
sonoma county and northern marin county, and generally less than
a tenth of an inch in all other areas. Rainfall is expected to end
by Friday.

A warming trend will begin over the upcoming weekend as a high
pressure ridge begins to build over california. This ridge will
strengthen into early next week and result in warm and dry
conditions districtwide on Monday and Tuesday.

Marine As of 09:07 am pdt Wednesday... Areas of fog this
morning across the coastal waters and into the bays. Winds will
increase over the bays this afternoon into tonight. A cold front
will move across the waters late tomorrow bringing chances of
light rain. A moderate to long period mixed northwesterly and
southerly swell has arrived with buoys reporting periods of 17 to
18 seconds across the waters. Late Thursday into Friday a large
northwesterly swell train will move across he area. This large
swell will create hazardous conditions.

Mtr watches warnings advisories
Tday Sca... Pt pinos to pt piedras blancas 0-10 nm from 2 pm
sca... Sf bay from 2 pm
public forecast: rgass
aviation: canepa
marine: as
fire weather: sims
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FTPC1 - 9414290 - San Francisco, CA 13 mi53 min W 5.1 G 6 51°F 58°F1018.7 hPa (+0.9)
46237 - San Francisco Bar, CA (142) 13 mi53 min 56°F4 ft
PXSC1 14 mi53 min 54°F 52°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 14 mi59 min NNW 1.9 G 5.1 52°F 1017.1 hPa
AAMC1 - 9414750 - Alameda, CA 15 mi53 min N 1 G 1.9 54°F 62°F1018.8 hPa (+1.0)
OKXC1 - 9414776 - Oakland (Berth 34), CA 16 mi53 min N 1 G 1.9 53°F 1018.3 hPa (+0.9)
OBXC1 16 mi53 min 53°F 51°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 16 mi53 min Calm G 1.9
LNDC1 17 mi53 min Calm G 1.9 53°F 1018.1 hPa (+0.8)
RTYC1 - 9414523 - Redwood City, CA 18 mi53 min Calm G 4.1 51°F 65°F1018 hPa (+1.0)
TIBC1 - Tiburon Pier, San Francisco Bay, CA 19 mi56 min NW 4.1 53°F 1018 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 20 mi63 min W 3.9 G 5.8 52°F 55°F5 ft1018 hPa (+0.6)
PPXC1 - 9414847 - Richmond (Point Potrero), CA 21 mi53 min SW 1 G 2.9 53°F 1018.6 hPa (+1.0)
RCMC1 - 9414863 - Richmond, CA 22 mi53 min NNW 1.9 G 2.9 51°F 59°F1018.3 hPa (+1.0)
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 26 mi63 min NW 7.8 G 12 53°F 55°F7 ft1017.8 hPa (+0.8)
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 33 mi53 min NW 4.1 G 6 52°F 1018.1 hPa (+0.9)
MZXC1 - 9415102 - Martinez-Amorco CA 35 mi53 min WNW 9.9 G 12 52°F 62°F1018.3 hPa (+0.9)52°F
PRYC1 - 9415020 - Point Reyes, CA 36 mi53 min WNW 1.9 G 2.9 55°F1018 hPa (+0.9)
PCOC1 - 9415144 - Port Chicago, CA 39 mi53 min WSW 9.9 G 12 53°F 62°F1017.9 hPa (+0.9)
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 44 mi53 min WNW 6 G 7 56°F 1017.2 hPa (+1.1)
SFXC1 - San Francisco Bay Reserve, CA 48 mi68 min WNW 2.9 53°F 1017 hPa47°F

Wind History for San Francisco, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA8 mi58 minENE 47.00 miOvercast50°F48°F94%1017.6 hPa
San Francisco, San Francisco International Airport, CA8 mi2 hrsN 07.00 miPartly Cloudy49°F44°F83%1017.7 hPa
San Carlos Airport, CA15 mi66 minN 02.50 miFog/Mist50°F50°F100%1018.6 hPa
Oakland, Metro Oakland International Airport, CA16 mi60 minN 04.00 miFog/Mist50°F50°F100%1018.3 hPa
Hayward, Hayward Air Terminal, CA21 mi59 minN 03.00 miMostly Cloudy with Haze52°F41°F66%1019.3 hPa
Palo Alto Airport, CA23 mi2.1 hrsN 02.00 miFog/Mist52°F0°F%1017.9 hPa

Wind History from HAF (wind in knots)
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Last 24hrCalmNW11N12NW9NW10NW12NW10NW10N7NW8CalmCalmN7CalmE4N5NE4N5CalmNE3N4NE5E5N4
1 day agoNE9NW6NW4NW6S6S8CalmNW5CalmCalmNE3CalmCalmCalmSE5N3CalmN3CalmN3CalmCalmN3NW5
2 days agoNE8
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--NW8NW8W5W4S4Calm----CalmCalmCalmCalmCalmNW4CalmNW6NW3CalmNW6NE7NE9NE7

Tide / Current Tables for Seaplane Harbor, San Francisco Bay, California
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Seaplane Harbor
Click for Map
Wed -- 05:54 AM PDT     0.80 feet Low Tide
Wed -- 06:08 AM PDT     Moonrise
Wed -- 07:21 AM PDT     Sunrise
Wed -- 12:12 PM PDT     7.36 feet High Tide
Wed -- 06:18 PM PDT     Moonset
Wed -- 06:27 PM PDT     Sunset
Wed -- 06:29 PM PDT     0.45 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
6.86.35.13.52.11.10.81.32.43.95.46.77.37.16.14.42.71.30.50.61.42.74.25.6

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
Wed -- 12:03 AM PDT     -0.01 knots Slack
Wed -- 03:10 AM PDT     -1.10 knots Max Ebb
Wed -- 06:08 AM PDT     Moonrise
Wed -- 06:12 AM PDT     0.01 knots Slack
Wed -- 07:21 AM PDT     Sunrise
Wed -- 09:20 AM PDT     1.07 knots Max Flood
Wed -- 12:20 PM PDT     -0.01 knots Slack
Wed -- 03:31 PM PDT     -1.22 knots Max Ebb
Wed -- 06:18 PM PDT     Moonset
Wed -- 06:27 PM PDT     Sunset
Wed -- 06:41 PM PDT     0.01 knots Slack
Wed -- 09:50 PM PDT     1.10 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0-0.6-1-1.1-1-0.7-0.10.40.91.110.70.2-0.4-0.9-1.2-1.2-1-0.50.20.711.10.9

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 (12,3,4,5)
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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.