Saturday, December16, 2017 L-36.com


Marine Weather and Tides
Montara, 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 7:17AMSunset 4:54PM Saturday December 16, 2017 4:14 PM PST (00:14 UTC) Moonrise 5:44AMMoonset 4:12PM Illumination 2% 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 Coastal Waters From Point Reyes To Pigeon Point California Out To 10 Nm- 223 Pm Pst Sat Dec 16 2017
.gale warning in effect until 9 pm pst this evening...
Tonight..N winds 15 to 25 kt. Gusts up to 40 kt this evening. Wind waves 5 to 8 ft, decreasing to 4 to 6 ft after midnight. W swell 4 to 6 ft at 12 seconds.
Sun..N winds 5 to 15 kt. Wind waves 3 to 4 ft. W swell around 5 ft at 12 seconds.
Sun night..NE winds up to 10 kt. Wind waves 2 ft or less. W swell around 5 ft at 12 seconds.
Mon..NE winds up to 10 kt. Wind waves 2 ft or less. NW swell 4 to 5 ft at 12 seconds.
Mon night..NE winds up to 10 kt. Wind waves 2 ft or less. W swell 4 to 5 ft at 11 seconds.
Tue..S winds up to 10 kt. Wind waves 2 ft or less. W swell 4 to 7 ft.
Tue night..W winds 5 to 10 kt. Wind waves 2 ft or less. W swell 5 to 7 ft.
Wed..NW winds 10 to 20 kt. Wind waves 3 to 4 ft. W swell 4 to 6 ft.
Thu..N winds 5 to 15 kt, becoming 5 to 10 kt. Wind waves 3 to 4 ft, then around 2 ft or less. NW swell 4 to 7 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 7 to 9 ft at 14 seconds. Across the bar...combined seas 7 to 9 ft at 14 seconds. Maximum ebb current of 1.9 knots at 02:48 pm Saturday and 0.7 knots at 03:30 am Sunday.
PZZ500 223 Pm Pst Sat Dec 16 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Gale conditions are forecast to ease this evening and overnight. Steep seas will remain through Sunday before subsiding on Monday. A cold front will arrive on Tuesday evening into Wednesday bringing some building swell. Northerly winds will increase behind the front causing building steep seas for mid to late week.

7 Day Forecast for Marine Location Near Montara, CA
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location: 37.57, -122.58     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 162227
afdmtr
area forecast discussion
national weather service san francisco bay area
227 pm pst Sat dec 16 2017

Locally breezy conditions likely through Sunday morning...

Elevated fire danger particularly for higher elevation
locations for the same time...

Synopsis Gusty northerly winds and dry conditions will persist
through the day and into early Sunday. Lighter winds, with above
average temperatures and dry conditions through the early part of
next week. A few hundredths of rain possible in the north bay
through mid week, then dry through most of the remainder of the
year.

Discussion As of 12:45 pm pst Saturday... A dry but energetic
vorticity wave swept through the state early this morning at a
very quick pace. As of noon, this feature has already pushed
eastward beyond the sierra nevada and was rapidly approaching the
utah state line. In the wake of this feature, the northerly
surface gradient has been trending upward (from 3mb acv->sfo 24
hours ago, to nearly 10mb acv->sfo in the last hour), resulting in
gusty north to northwest winds throughout the region. These strong
winds initially arrived overnight with the passage of the cold
frontal boundary and were focused primarily over the highest
elevations, with lighter winds near the surface due to the
presence of a nocturnal inversion. As the nocturnal inversion was
eroded by the rising sun, the energy from these winds aloft was
able to transfer their momentum to lower elevation locations,
including most of our major population centers. So far today, the
strongest wind gust reported was 65 mph at mount diablo, with 61
mph at los vaqueros raws (situated southeast of mount diablo and
north of the altamont pass), with several other locations from
around the area clocking in above 45 mph: mt tamalpais, bodega
bay, point reyes, oakland hills, half moon bay, inland san benito
county, the carquinez strait delta, and others.

Due to these winds, a wind advisory remains in effect for
locations at or above 1000 feet throughout the area. In addition,
gale warnings are in effect for most of the coastal waters.

Finally, due to the dry antecedent conditions and these gusty
northerly winds, a red flag warning is also in effect for
locations at or above 1000 feet throughout the area for the
potential for extreme fire risk and potential for rapid fire
growth. Overall, humidity values at our driest locations are
ranging from the mid teens to mid 20s as of noon, however, these
values will continue to drop into the afternoon as temperatures
rise (to somewhat above average values for this time of the year).

The wind advisory and red flag warning will remain in effect
through 10 am Sunday morning as these dry conditions and gusty
north winds are expected to gradually taper off through this
window before dropping below criteria tomorrow morning. The most
common question associated with all these products is if the area
has ever had a red flag warning this late into the year before.

The answer is, yes, we have, but it is rather rare. Not
unprecedented, but rare, which would go along with the fact we on
track for one of the driest decembers on record (per downtown san
francisco, only 1989 and 1876 were drier).

Forecast models then shows a moderately amplified ridge building
into the region as early as tomorrow in the wake of todays
disturbance, bringing continued dry conditions and above average
temperatures through at least Tuesday. Models then show a positively
tilted trough (a negatively tilted is generally preferred for a
stronger system) descending into northern california on Wednesday.

This system lacks sufficient moisture to bring widespread, or any,
rainfall to most locations, however, it could provide a glancing
blow to the north bay, and bring a few hundredths there. Otherwise,
the 384-hour GFS shows dry conditions persisting throughout the
state through essentially the remainder of the year. The CPC 8-14
day analysis would tend to agree with this drier diagnosis, however,
the CPC 3-4 week forecast shows above average rainfall chances for
the region, so that is something to keep an eye on for 2018. For
what its worth, both the GFS and euro show a very high amplitude,
but narrow, ridge situated over the west coast on december 25th.

Aviation As of 10:15 am pst Saturday... 18z TAF package.VFR
conditions will dominate airports around the bay area monterey bay
regions. The main story will be gusty northerly winds. Local
observations have already shown increasing winds around the area,
such as gusts to 61 mph east of livermore. As daytime warming
occurs vertical mixing should become more effective, which will
help to bring some of the higher level winds to the surface. As
such, strong gusty conditions remain in the tafs today. The
strongest winds will remain just off the surface, so wind shear
remains or was introduced for all TAF sites. Winds will begin to
ease late afternoon and early evening from north to south.

Confidence in timing is high and moderate to high for wind speeds.

If anything, winds could be a little stronger than forecast.

Vicinity of ksfo...VFR. Northerly winds will continue to increase
today in the wake of a dry cold front. Sustained winds in the 15
to 25 kt range with gusts to 35 kt are expected.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR. Northerly winds will increase midday
into afternoon today. Sustained winds in the 10 to 15 kt range
with gusts around 20 kt expected.

Fire weather As of 3:15 am pst Saturday... A red flag warning
remains in effect through 10 am Sunday. Offshore flow is forecast
to strengthen through the day. Latest models continue to show rh
values dropping through day and poor recoveries Saturday night.

It's fairly common to have lower rh on night number two behind a
front with developing offshore flow. May not technically hit rh
criteria the first part of today, but decided to keep fire
weather concerns going given gusty winds, lack of recent rain,
very low rh (single digits) the last few nights and near record
values of ercs for the N bay mts and santa cruz diablo psas. Areas
of greatest concern will be above 1000 feet. Winds may be a tad
weaker on Saturday night, but rh recoveries worse. For what it's
worth, fire weather concerns are not that unusual for this time of
year. December 16, 2013, a wildfire broke out in big sur called
the pfeiffer fire.

Marine As of 02:26 pm pst Saturday... Gale conditions are
forecast to ease this evening and overnight. Steep seas will
remain through Sunday before subsiding on Monday. A cold front
will arrive on Tuesday evening into Wednesday bringing some
building swell. Northerly winds will increase behind the front
causing building steep seas for mid to late week.

Mtr watches warnings advisories
Tngt Wind advisory... Caz507-511-512-517-518
glw... Pt reyes to pigeon pt 0-10 nm until 9 pm
glw... Pigeon pt to pt pinos 0-10 nm until 9 pm
glw... Pt pinos to pt piedras blancas 0-10 nm until 9 pm
glw... Pigeon pt to pt piedras blancas 10-60 nm until 9 pm
glw... Pt arena to pigeon pt 10-60 nm until 3 am
sca... Pt arena to pt reyes 0-10 nm
sca... Sf bay until 3 am
sca... Mry bay until 3 am
public forecast: drp
aviation: bfg as
marine: bfg
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
46237 - San Francisco Bar, CA (142) 15 mi44 min 54°F7 ft
FTPC1 - 9414290 - San Francisco, CA 17 mi44 min N 17 G 22 62°F 54°F1014.2 hPa
PXSC1 19 mi44 min 61°F 34°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 19 mi44 min NW 14 G 19 59°F 1013.1 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 19 mi84 min NW 21 G 25 55°F 55°F10 ft1014.5 hPa (-0.9)
RTYC1 - 9414523 - Redwood City, CA 20 mi44 min NNW 19 G 24 61°F 54°F1013.7 hPa
AAMC1 - 9414750 - Alameda, CA 20 mi44 min N 17 G 25 63°F 54°F1013.5 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 21 mi44 min N 19 G 25
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 21 mi84 min NNW 23 G 27 55°F 57°F13 ft1013.7 hPa (-0.4)
OKXC1 - 9414776 - Oakland (Berth 34), CA 21 mi44 min N 19 G 25 60°F 1013.8 hPa
OBXC1 21 mi44 min 62°F 29°F
LNDC1 22 mi44 min NNW 13 G 22 64°F 1013.6 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 23 mi40 min NNW 18 60°F 1014 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 26 mi56 min N 16 G 26 64°F 1014.2 hPa
RCMC1 - 9414863 - Richmond, CA 26 mi44 min N 18 G 27 63°F 54°F1013.6 hPa
PRYC1 - 9415020 - Point Reyes, CA 36 mi44 min WNW 19 G 22 54°F1015 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 38 mi44 min NNW 16 G 20 62°F 1014.2 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 40 mi44 min N 19 G 25 63°F 53°F1013.9 hPa15°F
PCOC1 - 9415144 - Port Chicago, CA 44 mi44 min NNW 23 G 26 61°F 53°F1013.4 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 49 mi44 min N 21 G 27 61°F 1013.4 hPa

Wind History for San Francisco, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA6 mi19 minN 18 G 275.00 miFair with Haze and Breezy55°F46°F72%1012.5 hPa
San Francisco, San Francisco International Airport, CA12 mi18 minN 2310.00 miA Few Clouds and Windy63°F23°F22%1013.7 hPa
San Carlos Airport, CA18 mi3.5 hrsNNW 16 G 2410.00 miPartly Cloudy63°F24°F24%1013.9 hPa
Oakland, Metro Oakland International Airport, CA21 mi21 minNNW 16 G 2410.00 miA Few Clouds63°F18°F17%1013.7 hPa

Wind History from SFO (wind in knots)
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Last 24hrW14W8W8W10W12W7W6W10W15W8W8W10W6NW15W9
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1 day agoN6W7E4CalmCalmCalmSE5CalmSW3S3SW4SW4S3S3S3CalmCalmCalmE4NE4N4CalmNE3N3
2 days agoCalmW9W10W10NW10W7W3W3CalmS3CalmW3SW4CalmCalmCalmCalmCalmNE4NE3N4NE3CalmN4

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
Click for Map
Sat -- 02:45 AM PST     2.48 feet Low Tide
Sat -- 05:42 AM PST     Moonrise
Sat -- 07:18 AM PST     Sunrise
Sat -- 08:43 AM PST     5.86 feet High Tide
Sat -- 03:44 PM PST     -0.37 feet Low Tide
Sat -- 04:12 PM PST     Moonset
Sat -- 04:53 PM PST     Sunset
Sat -- 10:35 PM PST     4.38 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
3.532.62.52.83.54.35.15.75.85.44.43.11.60.5-0.2-0.300.81.82.83.74.34.3

Tide / Current Tables for South Channel, San Francisco Bay Approach, California Current
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South Channel
Click for Map
Sat -- 01:30 AM PST     -0.86 knots Max Ebb
Sat -- 04:28 AM PST     0.01 knots Slack
Sat -- 05:43 AM PST     Moonrise
Sat -- 07:19 AM PST     Sunrise
Sat -- 07:19 AM PST     1.06 knots Max Flood
Sat -- 10:30 AM PST     -0.01 knots Slack
Sat -- 01:36 PM PST     -1.77 knots Max Ebb
Sat -- 04:12 PM PST     Moonset
Sat -- 04:52 PM PST     Sunset
Sat -- 05:19 PM PST     0.00 knots Slack
Sat -- 08:29 PM PST     1.40 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.5-0.8-0.8-0.7-0.30.30.8110.80.3-0.4-1.2-1.7-1.7-1.5-1-0.30.51.11.41.41.10.6

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 (19,4,5,8)
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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.