Thursday, December13, 2018 L-36.com


Marine Weather and Tides
Petaluma, 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 7:17AMSunset 4:52PM Thursday December 13, 2018 12:47 PM PST (20:47 UTC) Moonrise 11:50AMMoonset 10:49PM Illumination 37% Phase: Waxing Crescent; Moon at 6 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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PZZ531 San Francisco Bay South Of The Bay Bridge- 818 Am Pst Thu Dec 13 2018
Today..N winds up to 10 kt.
Tonight..SE winds up to 10 kt.
Fri..S winds 10 to 20 kt with gusts up to 30 kt. Rain likely.
Fri night..S winds 5 to 15 kt with gusts up to 25 kt. Rain likely.
Sat..SE winds 5 to 10 kt. A chance of showers.
Sat night..E winds around 5 kt.
Sun..S winds 10 to 15 kt. Rain.
Mon..W winds around 5 kt. A chance of showers.
PZZ500 818 Am Pst Thu Dec 13 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Northwest swell will increase across the waters through Friday night creating hazardous conditions particularly for smaller vessels. A significant long period northwest swell is then expected to arrive late Sunday into Monday through Tuesday, with very long period forerunners arriving Sunday morning.


7 Day Forecast for Marine Location Near Petaluma, CA
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location: 38.22, -122.6     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 131732
afdmtr
area forecast discussion
national weather service san francisco bay area
932 am pst Thu dec 13 2018

Synopsis Dry conditions are forecast to continue across our
region through Thursday night with mild temperatures. A weak
weather system will likely produce light rain later Friday and
Friday night, especially for areas north of the golden gate.

Periods of light rain may continue into Saturday, mainly for the
north bay. A stronger and wetter system is then expected to
produce widespread rain across our entire region Sunday afternoon
and Sunday night.

Discussion As of 09:15 am pst Thursday... Upper level ridge
keeping the area dry and mild today. A few high clouds moved
overhead through the night, and combined with lower dew points
near the surface, prevented fog from becoming widespread or dense.

Have updated the forecast to remove mention of fog this morning
in all but the easternmost part of the east bay valleys, and
southern salinas valley. The dry atmosphere and mostly clear skies
allowed temperatures overnight to drop to their coolest values in
several nights, with 30s in most inland valley locations and 40s
near the coast. Highs today will be mild under sunny skies, with
low to mid 60s near the sf bay and mid to upper 60s in the
central coast and southern inland valleys. A few of the warmest
locations could hit 70 degrees.

High clouds will increase late tonight in advance of the next
upper level trough. A few prefrontal showers will likely develop
by late Friday morning in the coastal mountains as moist onshore
flow increases. A cold front will move south into the north bay
on Friday afternoon and stall out and mostly fall apart over the
sf bay Friday evening. Showers will accompany the front with light
rainfall amounts from the bay area north. Lowland areas to the
south will struggle to see any rain from this front. The stalled
front will then lift north into the north bay on Saturday and will
keep a chance of scattered showers in the forecast across the
north. A stronger storm is still expected to arrive on Sunday with
widespread moderate to locally heavy rainfall. See the previous
discussion for more details.

Prev discussion As of 03:08 am pst Thursday... Longwave pattern at
500mb shows a ridge of high pressure off the west coast and over
the bay area. A quick look at the satellite imagery confirms this
flow pattern as cloud continue spill over the ridge spreading high
clouds over the bay area. At the surface some patchy fog is
forming, but compare to the last few nights it's having a hard
time. Dew points are lower than 24 hours ago and high clouds are
likely limiting some of the cooling. None the less, a few stations
in the north and east bay valleys have reduced visibility less
than 10 miles. A station in king city also has some reduced
visibility. Have not seen any reports of dense fog however.

The ridge of high pressure will keep the region dry and seasonable
today through early Friday. Total side note, some clearing of high
clouds may allow for a glimpse of the geminid meteor shower
overnight. Saw a few meteors here at the wfo.

By Friday afternoon the ridge exits to the east as a cold front
approaches from the north. Model guidance continues to show the
possibility of a few pre-frontal showers over the coastal
mountains during the day Friday. Rain chances will increase and be
highest north of the santa cruz mountains Friday afternoon. Rain
chances drop off rather quickly south of the santa cruz as the
cold front struggles to move south. In fact, it appears the
frontal boundary weakens and stalls over the bay area and slowly
lifts northward back over the north bay. The stalled front will
keep shower chances through Saturday. Rainfall amounts will be a
few hundredths south of the santa cruz mountains, 0.10-0.25" santa
cruz mountains, 0.10-0.50" north of the santa cruz mountains.

The main focus continues to be on a more potent storm system that
will impact the region on Sunday. A stronger cold front will enter
far norcal early Sunday and then slowly move southward. This front
has a better moisture tap - 1-1.25" pwat. Atmospheric river
guidance has ivt values greater than 500 kg m S - moderate
strength. The ensemble envelop was rather large with the ivt
values earlier in the week, but the latest gfes has a tighter
envelop increasing confidence. Moderate to possible heavy rain
will develop over the north bay Sunday afternoon before slowly
moving south Sunday night into Monday. A few post frontal showers
will be possible on Monday, but gradual drying seems likely.

Rainfall will be highest over the north bay and all coastal
mountains.

The tail end of a system well to the north may bring some showers
to portions of norcal, but chances to the bay area seem small. If
anything, the north bay would have the best chance on
Tuesday Wednesday. Farther down the road the gfs ECMWF both show
another front possible late next week, but details and timing
vary.

Simply put, more beneficial rain is on the way through the next
seven days.

Aviation As of 9:40 am pst Thursday... Ridge apex over central
california resulting in widespreadVFR with generally light
offshore winds and passing high clouds to the north this morning.

Arriving frontal boundary will bring increasing cloud cover from
north to south through the TAF period, with a shift towards wetter
showery pre frontal weather towards the end of the TAF period for
the northern 30-hour TAF sites.

Vicinity of ksfo...VFR today. Increasing clouds through the taf
period with prefrontal showers possible mid to late Friday
morning.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR. Breezy upvalley (se) winds in the
salinas valley thru this morning. Increasing clouds towards end of
taf period ahead of next frontal boundary.

Marine As of 09:29 am pst Thursday... Northwest swell will
increase across the waters through Friday night creating hazardous
conditions particularly for smaller vessels. A significant long
period northwest swell is then expected to arrive late Sunday
into Monday through Tuesday, with very long period forerunners
arriving Sunday morning.

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: drp
marine: drp
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 21 mi48 min E 12 G 14 53°F 1024.6 hPa (-1.3)
RCMC1 - 9414863 - Richmond, CA 23 mi48 min NE 9.9 G 14 57°F 56°F1024.1 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 24 mi49 min NE 8.9 56°F 1025 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 25 mi48 min NE 9.9 G 14 59°F 1024.6 hPa (-1.4)
PRYC1 - 9415020 - Point Reyes, CA 25 mi48 min 56°F1023.3 hPa (-1.7)
MZXC1 - 9415102 - Martinez-Amorco CA 28 mi48 min ENE 5.1 G 8 52°F 54°F1025.2 hPa (-1.7)52°F
FTPC1 - 9414290 - San Francisco, CA 29 mi48 min NNE 15 G 17 56°F 56°F1024.2 hPa (-1.5)
SFXC1 - San Francisco Bay Reserve, CA 30 mi63 min E 12 55°F 1025 hPa37°F
46237 - San Francisco Bar, CA (142) 30 mi48 min 56°F8 ft
PXSC1 31 mi48 min 57°F 43°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 31 mi48 min N 8 G 11 57°F 1023.1 hPa (-1.5)
OKXC1 - 9414776 - Oakland (Berth 34), CA 32 mi48 min N 7 G 8 56°F 1024.1 hPa (-1.5)
PCOC1 - 9415144 - Port Chicago, CA 32 mi48 min ENE 11 G 13 51°F 53°F1025.1 hPa (-1.8)
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 32 mi48 min NNW 5.1 G 5.1
OBXC1 32 mi48 min 62°F 40°F
LNDC1 34 mi48 min E 5.1 G 8.9 61°F 1023.9 hPa (-1.6)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 35 mi38 min ENE 12 G 16 58°F 57°F1023.5 hPa
AAMC1 - 9414750 - Alameda, CA 35 mi48 min W 1.9 G 1.9 59°F 55°F1024.3 hPa (-1.6)
46013 - Bodega Bay - 48NM North Northwest of San Francisco, CA 37 mi38 min E 9.7 G 14 57°F1023.1 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 40 mi48 min E 5.1 G 5.1 50°F 1025.4 hPa (-1.5)

Wind History for Richmond, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Petaluma Municipal Airport, CA3 mi53 minSSE 910.00 miFair55°F41°F59%1024.4 hPa
Novato / Gnoss Field, CA6 mi53 minS 410.00 miFair59°F37°F45%1024.7 hPa
Napa, Napa County Airport, CA17 mi54 minE 1110.00 miFair58°F37°F46%1023.8 hPa
Santa Rosa, Santa Rosa Sonoma County Airport, CA23 mi55 minno data10.00 miFair55°F0°F%1023.2 hPa

Wind History from O69 (wind in knots)
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Last 24hrW6NW6
G13
W9W9W7CalmCalmCalmCalmCalmSE4CalmCalmCalmCalmCalmCalmCalmCalmCalmCalm5SE9SE9
1 day agoNW5NW4W5W5CalmCalmCalmCalmCalmN3CalmCalmN4CalmCalmW4CalmCalmCalmCalm3CalmNW4W6
G11
2 days agoCalmW5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmN3CalmCalmW4NW5

Tide / Current Tables for Upper drawbridge, Petaluma River, San Pablo Bay, California
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Upper drawbridge
Click for Map
Thu -- 12:03 AM PST     0.18 feet Low Tide
Thu -- 06:41 AM PST     5.53 feet High Tide
Thu -- 07:18 AM PST     Sunrise
Thu -- 11:49 AM PST     Moonrise
Thu -- 12:59 PM PST     2.58 feet Low Tide
Thu -- 04:50 PM PST     Sunset
Thu -- 05:05 PM PST     5.31 feet High Tide
Thu -- 10:49 PM PST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.20.51.32.53.74.85.45.55.24.63.83.22.72.62.93.84.85.35.24.73.92.91.91.1

Tide / Current Tables for Petaluma River Approach, San Pablo Bay, California Current
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Petaluma River Approach
Click for Map
Thu -- 02:31 AM PST     0.63 knots Max Flood
Thu -- 06:20 AM PST     -0.00 knots Slack
Thu -- 07:17 AM PST     Sunrise
Thu -- 08:49 AM PST     -0.39 knots Max Ebb
Thu -- 11:31 AM PST     0.00 knots Slack
Thu -- 11:48 AM PST     Moonrise
Thu -- 01:37 PM PST     0.42 knots Max Flood
Thu -- 04:40 PM PST     -0.00 knots Slack
Thu -- 04:50 PM PST     Sunset
Thu -- 08:01 PM PST     -0.79 knots Max Ebb
Thu -- 10:48 PM PST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.20.50.60.60.50.30.1-0.2-0.3-0.4-0.3-0.10.20.40.40.30.2-0.1-0.4-0.7-0.8-0.7-0.6-0.4

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 (15,3,4,5)
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Ground Weather Radar Station Sacramento, 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.