Sunday, February18, 2018 L-36.com


Marine Weather and Tides
Plymouth, 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 6:48AMSunset 5:47PM Sunday February 18, 2018 1:01 AM PST (09:01 UTC) Moonrise 8:33AMMoonset 8:44PM Illumination 10% Phase: Waxing Crescent; Moon at 3 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- 841 Pm Pst Sat Feb 17 2018
.small craft advisory in effect from Sunday morning through late Sunday night...
Tonight..W winds 10 to 20 kt.
Sun..W winds 15 to 25 kt.
Sun night..NW winds 15 to 25 kt.
Washingtons birthday..NW winds 15 to 25 kt.
Mon night..NW winds 15 to 25 kt.
Tue..W winds 10 kt.
Wed..N winds 10 kt.
Thu..Light winds...becoming W 5 kt.
PZZ500 841 Pm Pst Sat Feb 17 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Low pressure dropping south along the west coast will result in increasing north to northwest winds. Small craft advisories will transition into gale warnings Monday night after a cold front pushes through. Winds will slowly decrease Tuesday and Wednesday.

7 Day Forecast for Marine Location Near Plymouth, CA
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location: 38.48, -120.84     debug


Area Discussion for - Sacramento, CA
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Fxus66 ksto 180650
afdsto
area forecast discussion
national weather service sacramento ca
1050 pm pst Sat feb 17 2018

Synopsis
A cold weather system brings breezy winds and snow over the
mountains and foothills Sunday into Monday, impacting travel.

This will be followed by near record cold temperatures with a
possible widespread freeze.

Discussion
Some clouds from the incoming goa trof are finally making their way
into the NRN portion of our CWA (shasta co) with the surface front
nearing the ca or border. As the front sags swd, cloud cover expected
to increase over the cwa. This system has a narrow pw plume around
.80" but is also getting eroded with the drier air associated with
the trof. Deeper moisture is associated with the vort MAX near
vcrisl which is forecast to move into wa or and never makes it into
our cwa.

Coldest air of the winter season expected to impact norcal beginning
sun. Coldest morning forecast to be Tue (20th) seemingly "likely" to
set min temp records at some of the main climo sites. Current goa
short wave will be driven swd by the nly (meridional) flow between
the ERN pac ridge and the polar vortex (pv) over the canadian arctic
archipelagos. This system will give norcal some showers mainly sun
afternoon mon, but moisture will be limited due to a lack of a tap
of subtropical moisture. This will keep amounts limited to a
few several tenths of an inch. However, the colder temps will create
high snow ratios with the plumes showing a mean of 3" for blu
through Mon nite, down from 5" yesterday which shows the lack of
moisture with this system.

Temp plumes for sac on Mon (19th) morning indicate a mean of 29 and
25 on the 20th, with some colder members, and 26 and 22 for rdd.

Thus, min temp records look vulnerable at the main climo sites early
next week. Jhm
feb 18 feb 19 feb 20 feb 21 feb 22
mod 29(1956) 29(1955) 28(1955) 29(1955) 32(1975)
rbl 29(1956) 28(2006) 28(2006) 27(2006) 30(1969)
rdd 29(2013) 25(2006) 25(2006) 29(2006) 29(2011)
dts 31(1990) 31(1882) 31(1953) 31(1955) 32(2013)
sac 29(1956) 33(1961) 30(2013) 29(2006) 30(1975)
sck 29(1975) 28(1955) 28(1955) 27(1953) 28(1951)

Previous discussion
A change in the weather pattern is in the works, as upper level
ridging shifts westward. This will allow a cold system from
western canada to drop into the region tonight through Monday.

This system does not have a strong moisture tap, but with cold air
aloft will be efficient as squeezing out what moisture is
available and producing high ratio snow. Snow levels are
expected to drop Sunday through Monday, starting around 5500 and
dropping to around 1000 feet by Monday morning. Periods of snow
will bring slippery conditions at times to mountain roads. Total
snow amounts of 4 to 6 inches are expected by late Monday
afternoon over the northern sierra. The foothills could see light
snow, with a dusting possible down to 1000 feet. A winter weather
advisory is in effect for the northern sierra, with impacts to
busy holiday travel expected. If you plan on traveling into the
northern sierra Sunday, travel in the morning if possible, the
earlier the better. The southern cascades, coastal range, and
mountains of western plumas county could see an inch or so of
snow.

Temperatures on Monday morning will be quite cold across the
region as cold air advects into the area with the cold trough. A
freeze watch remains in effect for late Sunday night through
Wednesday morning. The coldest temperatures are expected on
Tuesday morning, as skies clear further. Forecast lows have
trended a little cooler, with widespread lows in the mid to upper
20s, and several hours of subfreezing temperatures. These could
break daily records, which are in the upper 20s to lower 30s for
valley locations. Northerly winds may keep temperatures slightly
less cold over the western side of the sacramento valley.

Widespread frost is expected. Agricultural impacts could be
significant, due to an early bloom from unusually mild weather in
recent weeks. People should begin planning now on ways to protect
sensitive plants, outdoor pets, and outdoor pipes. Wednesday looks
slightly less cold, as the airmass warms a little. Ek
.Extended discussion (Wednesday through Saturday)
models show a series of short wave troughs embedded within the
long wave trough to pass through the region during the extended
period. There is quite a bit of disagreement with timing and
placement of these short waves though. The GFS has them set up to
our east and is much drier while the ec is further west and is
able to pull in some moisture and is also deeper with them.

Unfortunately confidence in the extended is quite low because of
this. Right now the greatest rain snow chances look to be Thursday
and again Saturday. With the systems originating from the NW they
will be cold systems with low snow levels. Snow levels with both
systems look to be around or below 3000. High temperatures for the
period will be slightly below normal to near normal and will be
slightly warmer each day. We will have to watch out for patchy
frost Thursday morning in the valley but otherwise overnight lows
should remain warm enough to avoid frost.

-cjm

Aviation
Vfr conditions expected at the TAF sites the next 24 hours. Low
clouds around 5000 feet will start to build in from north to south
this evening and overnight. Scattered snow showers can be expected
in the higher elevations and MVFR will be possible in any shower
activity. Cig will become more bkn after 18z Sunday between 5000
and 10000 feet. Winds increase this evening becoming 5-15 knots
and continue into Sunday.

-cjm

Sto watches warnings advisories
Winter weather advisory from 10 am Sunday to 4 pm pst Monday for
west slope northern sierra nevada.

Freeze watch from late Sunday night through Wednesday morning
for carquinez strait and delta-central sacramento valley-clear
lake southern lake county-motherlode-mountains southwestern
shasta county to northern lake county-northeast
foothills sacramento valley-northern sacramento valley-northern
san joaquin valley-shasta lake area northern shasta county-
southern sacramento valley.



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
SFXC1 - San Francisco Bay Reserve, CA 66 mi76 min W 9.9 51°F 1015 hPa48°F
PCOC1 - 9415144 - Port Chicago, CA 70 mi43 min SSW 5.1 G 8 51°F 54°F1015.5 hPa
AAMC1 - 9414750 - Alameda, CA 92 mi49 min W 9.9 G 14 52°F 56°F1016.9 hPa

Wind History for Port Chicago, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure

Wind History from MHR (wind in knots)
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Last 24hrCalmCalmCalmCalmSE6------NE3NE3N3W3S5NE3CalmCalmCalmSE3S3S6------SE4
1 day agoNW6CalmS3SE6SE8SE6----Calm----CalmE3CalmNE3E4CalmCalmCalmNW4W5NW10N8NW4
2 days ago--SW14S7SE7SE6SE6----N5N4N7N7NW11NW11NW10NW13NW13NW15N16
G21
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NW16N8

Tide / Current Tables for Clarksburg, Sacramento River, California
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Clarksburg
Click for MapNote: These data apply only during low river stages.

Sun -- 02:32 AM PST     0.09 feet Low Tide
Sun -- 06:52 AM PST     Sunrise
Sun -- 07:45 AM PST     2.75 feet High Tide
Sun -- 08:35 AM PST     Moonrise
Sun -- 02:50 PM PST     0.55 feet Low Tide
Sun -- 05:47 PM PST     Sunset
Sun -- 07:18 PM PST     2.83 feet High Tide
Sun -- 08:47 PM PST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.70.30.10.10.61.42.22.62.72.62.21.81.30.90.60.60.91.62.42.82.82.52.11.6

Tide / Current Tables for Clarksburg #4, Sacramento River, California
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Clarksburg #4
Click for Map
Sun -- 02:32 AM PST     0.08 feet Low Tide
Sun -- 06:52 AM PST     Sunrise
Sun -- 07:44 AM PST     2.74 feet High Tide
Sun -- 08:35 AM PST     Moonrise
Sun -- 02:50 PM PST     0.54 feet Low Tide
Sun -- 05:47 PM PST     Sunset
Sun -- 07:18 PM PST     2.82 feet High Tide
Sun -- 08:47 PM PST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.70.30.10.10.61.42.22.62.72.62.21.71.30.90.60.50.91.62.42.82.82.52.11.6

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 Sacramento, CA (4,6,7,8)
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Ground Weather Radar Station Sacramento, 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.