Saturday, December15, 2018 L-36.com


Marine Weather and Tides
Pescadero, 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 7:14AMSunset 4:53PM Saturday December 15, 2018 1:01 PM PST (21:01 UTC) Moonrise 12:47PMMoonset 12:00AM Illumination 58% 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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PZZ560 Coastal Waters From Pigeon Point To Point Pinos California Out To 10 Nm- 757 Am Pst Sat Dec 15 2018
.small craft advisory in effect through Sunday afternoon...
Today..SE winds 10 to 20 kt with gusts up to 25 kt... Diminishing to 5 to 15 kt this afternoon. Wind waves 2 ft or less. W swell 8 to 11 ft at 14 seconds. A slight chance of showers this morning.
Tonight..S winds 10 to 20 kt with gusts up to 25 kt. Wind waves 2 ft or less. W swell 7 to 9 ft at 13 seconds. A slight chance of showers.
Sun..S winds 15 to 25 kt with gusts up to 30 kt. Wind waves 3 to 5 ft. W swell 6 to 8 ft at 16 seconds. Rain.
Sun night..S winds 20 to 25 kt with gusts up to 30 kt. Wind waves 3 to 5 ft. W swell 13 to 18 ft at 21 seconds. Showers and a slight chance of Thunderstorms.
Mon..NW winds 5 to 15 kt. Wind waves 2 ft or less. W swell 16 to 20 ft at 20 seconds. A slight chance of showers.
Mon night..NW winds 5 to 10 kt. Wind waves 2 ft or less. W swell 13 to 18 ft at 18 seconds.
Tue..N winds 5 to 10 kt. Wind waves 2 ft or less. W swell 10 to 12 ft.
Wed..NE winds up to 10 kt. Wind waves 2 ft or less. W swell 10 to 15 ft. Winds and wind waves higher in and near Thunderstorms.
PZZ500 757 Am 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 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.


7 Day Forecast for Marine Location Near Pescadero, CA
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location: 37.18, -122.39     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 151745
afdmtr
area forecast discussion
national weather service san francisco bay area
945 am 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 09:20 am pst Saturday... Scattered showers
continue across the north bay this morning as a weak disturbance
interacts with a frontal boundary and relatively high pwat. These
showers have been light with hourly rainfall rates of only a few
hundredths, and overnight morning rainfall totals less than a
quarter inch in the north bay valleys and less than a half inch in
the surroundings mountains. Models indicate scattered showers
will remain possible through the afternoon and evening, mainly
confined to the north bay. Clouds and precipitation will keep
temperatures cool across the north bay this afternoon with upper
50s to near 60 expected. Elsewhere, dry conditions are expected
with high clouds moving overhead. Mild temperatures are expected
from the golden gate south with low to mid 60s anticipated.

Satellite IR imagery reveals a well-defined and deep trough
in the north pacific. This trough will bring widespread moderate
to locally heavy rainfall, breezy to gusty southerly winds, and
even a slight chance of thunderstorms Sunday afternoon through
early Monday morning. The band of locally heavy rainfall is likely
to be situated along a cold front moving through our northern
regions Sunday afternoon and pushing south and east through Sunday
night. This trough is also generating a very large swell which
will impact the coast Sunday through late Monday. The trough and
its associated impacts will be the focus of the forecast this
afternoon. For additional details, see the previous discussion.

For details about impacts to the coast, see the beaches section
below.

Prev discussion As of 3:32 am pst Saturday... The cold front that
brought rain to the region on Friday has become nearly stationary
and is currently bisecting sf bay. Kmux radar imagery is rather
quiet this morning, but a few automated gauges tipped 0.01-0.03"
over the north bay. Latest forecast models lift the frontal
boundary slowly northward today as a potent storm system
approaches from the west. Warm advection and isentropic lift will
increase from sf northward today. Therefore, scattered showers
will continue with a few additional 0.01" of precip. Areas south
of the golden gate appear to be dry with an outside chance for an
isolated showers. In fact, it should be a nice mild december day
for southern areas.

Now onto the main event. For several days now the focus has been
on an atmospheric river taking aim at california.

Overnight water vapor imagery shows a rather wrapped up storm
system spinning south of the aleutian islands. This storm system
will be the main weather maker for much of the region Saturday
night through Monday. Latest timing of the potent cold front is
Sunday afternoon before pushing through the region Sunday evening
into early Monday. The peak rainfall will likely occur with the
fropa. Ahead of the front, light to moderate rain will develop
over the north bay Saturday night into Sunday. Rain coverage and
intensity will increase over the north bay early Sunday before
spreading southward through the day. Unlike previous storm system
this one will have plenty of moisture to work with. Latest tpw
imagery puts values of 1-1.5" or 150-200% percent of normal.

Simply put there is moisture to work with. Atmospheric river
guidance has been rather consistent for several days now
indicating ivt over 500 kg m s, which would fall into the moderate
category and be one of the stronger ars of the 2018 season. Once
the upper level trough arrives Sunday afternoon it will help to
push the front through the region. Additionally, the upper level
trough will increase upper level support and increase overall
instability. Model guidance shows rather decent surface and mid-
level instability Sunday afternoon through early Monday. Decided
to add a 15-20% chc of thunderstorms with the fropa. It should be
noted that the storm prediction center has a large portion of ca
in a general mention of thunder Sunday into Monday. Given the
landfalling ar and convective potential there could be a brief
period of moderate to heavy rainfall leading to minor
flooding ponding on roads and urban areas.

A more showery regime will set up late Sunday night over northern
areas behind the front and then slowly spread S and E Monday
afternoon. Rainfall totals tonight through Monday will be greatest
over the north bay and coastal mountains 1-3" - locally 3+" north
bay peaks and santa lucias. Other locations generally 0.5-1" and
lesser amounts over interior san benito southern monterey county.

Gusty southerly winds will develop on Sunday and continue through
Sunday night. Not strong enough for a wind advisory, but gusts of
40 mph and locally 50 mph will be possible. Winds will be
strongest over the higher terrain and near the coast.

Drier weather returns mid week with a decent ridge building in.

Temperatures will be rather pleasant midweek as well with 850mb
temps near 15c. Highs will be in the 60s to lower 70s.

Rain chances late next week are looking less and less as models
are trending drier.

Lastly, one final concern for Sunday into Monday will be minor
coastal flooding. A very large swell will build Sunday and impact
the coast Monday (see below for specific details). The combination
of building swell, rain runoff, onshore flow and lead up to king
tides (dec 22 23) may result in some coastal flooding. Utilizing
the extra-tropical storm surge model does show a brief period on
Sunday were water levels may be high enough for some minor coastal
flooding. Locations most likely impacted will be low spots near
mill valley, embarcadero, rec trails on the bay shoreline and any
low spots near a slough. Would like to see a higher than normal
tidal cycle during peak swell before issuing a coastal flood
advisory.

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
Tday 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
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 24 mi32 min E 2.9 G 5.1 61°F 55°F1018.5 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 27 mi72 min ESE 12 G 16 56°F 58°F11 ft1018.3 hPa (+0.0)
46114 - West Monterey Bay, CA 32 mi32 min 58°F13 ft
46092 - MBM1 35 mi58 min NE 9.7 55°F 58°F1019 hPa (-0.3)
AAMC1 - 9414750 - Alameda, CA 41 mi38 min S 1.9 G 2.9 55°F 55°F1018.6 hPa
MLSC1 - Moss Landing, South Harbor, CA 41 mi22 min ESE 2.9 G 8 60°F 1019.1 hPa48°F
OBXC1 43 mi32 min 55°F 54°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 43 mi32 min SSW 4.1 G 5.1
PXSC1 43 mi32 min 59°F 51°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 43 mi32 min SSE 5.1 G 7 58°F 1017.3 hPa
LNDC1 43 mi32 min WSW 4.1 G 5.1 58°F 1018 hPa
ELXC1 - Elkhorn Slough Reserve, CA 43 mi77 min SSW 4.1 61°F 1020 hPa50°F
FTPC1 - 9414290 - San Francisco, CA 43 mi38 min SSE 4.1 G 6 58°F 56°F1018.5 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 44 mi32 min SW 4.1 G 5.1 56°F 1018.2 hPa
46237 - San Francisco Bar, CA (142) 44 mi32 min 56°F9 ft
46240 - Cabrillo Point, Monterey Bay, CA (158) 46 mi32 min 59°F5 ft
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 46 mi32 min SSE 16 G 19 58°F 1018 hPa
MEYC1 48 mi86 min 58°F1019.9 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 49 mi27 min SE 5.1 57°F 1018 hPa

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA24 mi62 minS 105.00 miA Few Clouds with Haze59°F53°F82%1018.6 hPa

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Last 24hrS18SE7S9----SW7E5S64----------------------5SE7--5
1 day agoN5N8------N10NE10Calm--Calm------------------Calm--SE14
G24
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2 days agoNW10----NW11--NW8W8W5CalmCalm------------------4CalmCalm4Calm

Tide / Current Tables for Ano Nuevo Island, California
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Ano Nuevo Island
Click for Map
Sat -- 03:49 AM PST     First Quarter
Sat -- 04:30 AM PST     4.37 feet High Tide
Sat -- 07:15 AM PST     Sunrise
Sat -- 11:01 AM PST     2.41 feet Low Tide
Sat -- 12:47 PM PST     Moonrise
Sat -- 03:50 PM PST     3.26 feet High Tide
Sat -- 04:53 PM PST     Sunset
Sat -- 10:18 PM PST     1.10 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.82.63.444.34.34.13.73.22.82.52.42.52.733.23.33.12.82.31.71.31.11.2

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
Click for Map
Sat -- 03:49 AM PST     First Quarter
Sat -- 04:48 AM PST     4.77 feet High Tide
Sat -- 07:17 AM PST     Sunrise
Sat -- 11:15 AM PST     2.51 feet Low Tide
Sat -- 12:47 PM PST     Moonrise
Sat -- 04:08 PM PST     3.66 feet High Tide
Sat -- 04:52 PM PST     Sunset
Sat -- 10:32 PM PST     1.20 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.82.63.54.24.64.84.64.13.63.12.72.52.62.83.23.53.73.63.22.72.11.61.31.2

Weather Map and Satellite Images
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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 (16,3,4,5)
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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.