Friday, January22, 2021
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Marine Weather and Tides
Copperopolis, CA

Version 3.4
NOTICE
8/26/2020 The 7 day forecast is taking about 5 seconds to load but it will eventually load. NOAA is still working on it.
8/18/2020 NOAA continues to have trouble. Wind guest will occasionally be left off graphs. I am working with NOAA to resolve the issue.
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.

Sunrise 7:12AMSunset 5:17PM Friday January 22, 2021 7:24 AM PST (15:24 UTC) Moonrise 12:29PMMoonset 1:52AM Illumination 68% Phase: Waxing Gibbous; Moon at 9 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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PZZ530 San Pablo Bay, Suisun Bay, The West Delta And The San Francisco Bay North Of The Bay Bridge- 200 Am Pst Fri Jan 22 2021
Today..W winds 10 to 20 kt. Showers likely and a slight chance of Thunderstorms.
Tonight..N winds up to 10 kt. A slight chance of showers.
Sat..N winds up to 10 kt.
Sat night..W winds around 5 kt.
Sun..SW winds up to 10 kt. Rain likely.
Sun night..NW winds 10 to 20 kt with gusts up to 30 kt. Rain likely.
Mon..NW winds 5 to 15 kt with gusts up to 25 kt.
Tue..S winds 10 to 20 kt with gusts up to 25 kt. Rain likely. Winds and wind waves higher in and near Thunderstorms.
PZZ500 200 Am Pst Fri Jan 22 2021
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Expect gusty winds, showers, and a slight chance of scattered Thunderstorms this morning and into the afternoon as a cold front moves through the waters. Unsettled weather will continue through much of the forecast period as a series of storms move through the region. The next one being on Sunday and into Monday. This front will be accompanied by widespread gusty winds with gale force conditions possible Sunday night into Monday morning. Another storm system is then expected mid next week. Moderate northwest swell will persist as a couple additional northwest swells arrive today and then on Sunday.


7 Day Forecast for Marine Location Near Copperopolis, CA
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location: 37.94, -120.54     debug


Area Discussion for - Sacramento, CA
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FXUS66 KSTO 221125 AFDSTO

Area Forecast Discussion National Weather Service Sacramento CA 325 AM PST Fri Jan 22 2021

SYNOPSIS. Periods of rain and snow Friday and into next week, bringing potential winter weather driving hazards. A much wetter storm is possible by the middle of next week.

DISCUSSION. Upper low just off the Nrn CA coast will be dropping SSEwd over the region today with scattered-numerous showers. This low pressure system is not associated with an AR so it does not have an abundance of moisture associated with it, but it will be associated with a cold pocket and steep mid level lapse rates. A few of the SREF CAPE plumes for SAC show nearly a couple hundred J/Kg for this afternoon with the GFS consistently highlighting instability over portions of the Srn Sac Vly/Nrn SJV for the last several days. Although forecast soundings are not impressive, can't rule out an isolated T-storm or two, or some graupel showers in the Mother Lode as short wave energy moves inland during the day. This is also been hinted by the higher resolution CAMs the last couple of days. Cumuliform cloudiness associated with the cold pocket could result in some breaks in the clouds later this morning and afternoon behind the front which is moving through this morning.

Heaviest precip amounts are forecast over the orographically favored Sierra with liquid amounts up to around a third of an inch to a half inch or so, and 2-4 inches of snow, and max amounts up to 5-7 inches in Srn zone 69. Heavier convective snow showers may occur down to 3000 to 3500 ft, otherwise our snow level is forecast to be around 4 kft. The convective nature of the snow showers is likely to cause some travel problems over the Sierra and will issue a WSW. Given the lack of moisture, will trend the QPF to the SREF mean/average for the Valley, but a little above the average in the orographically favored areas.

Today's high temps will be at least 5-15 degrees cooler than yesterday, and we have seen the last of widespread 60s in the Valley for quite a while. Saturday should see some clearing and modestly warming temperatures as the trof departs, otherwise colder wx is ahead. A few light snow showers could linger over the Sierra Crest south of I-80 on Sat as secondary energy drops Swd along the W coast reforming the closed low circulation to our south. This could cause backwash clouds/showers to linger into Sat. Otherwise, clearing behind the initial system could allow some patchy frost in the Valley Sat morning.

Another trof and cold front are forecast to bring a reinforcing shot of cooler and showery weather to Norcal Sun/Sun nite, and lingering over the Sierra into Mon. This is a modestly wetter system, but not associated with an AR. However, an AR storm looks more promising around the middle of next week according to the GEFS mean, less so according to the ECMWF ensemble mean.

EXTENDED DISCUSSION (Tuesday THROUGH Friday).

Decreasing shower threat on Tuesday as short wave upper ridging moves through. Next Pacific frontal system follows with more widespread precipitation spreading across the CWA Wednesday afternoon into night. Abundant moisture associated with this system resulting in significant QPF. Several feet of snow is possible in the higher elevations through midweek. Threat of showers continues Thursday into Friday with upper trough.

AVIATION.

Areas of MVFR poss in pcpn with lcl IFR/LIFR, mnly omtns, as Pac fntl sys movs thru intr NorCal nxt 24 hrs. Sn lvls 030-040 AGL. Isold tstm poss in Cntrl Vly, S of KOVE, tda btwn 20z-02z. Sfc wnd genly blo 12 kts exc lcl SWly sfc wnd gsts up to 25 kts poss ovr hyr mtn trrn tda.

STO WATCHES/WARNINGS/ADVISORIES. Winter Weather Advisory from 10 AM this morning to 10 PM PST this evening for West Slope Northern Sierra Nevada.




Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
PCOC1 - 9415144 - Port Chicago, CA 80 mi54 min SW 9.9 G 11 48°F 51°F1012.6 hPa
SFXC1 - San Francisco Bay Reserve, CA 81 mi99 min W 9.9 48°F 1012 hPa46°F
RTYC1 - 9414523 - Redwood City, CA 94 mi54 min SW 5.1 G 6 49°F 54°F1014.7 hPa

Wind History for Port Chicago, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
COLUMBIA, CA9 mi29 minN 010.00 miOvercast43°F28°F57%1012.2 hPa

Link to 5 minute data for KO22

Wind History from O22 (wind in knots)
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Last 24hrCalmCalmCalmCalmS54S4S5S4CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm3CalmCalm
1 day agoCalmCalmCalmCalmSW3SW44SW5W5CalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalm
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3S4CalmCalmCalmCalm334NW54W4CalmCalmCalmCalmCalm

Tide / Current Tables for Holt, Whiskey Slough, San Joaquin River, California
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Holt
Click for Map
Fri -- 01:51 AM PST     2.50 feet High Tide
Fri -- 01:55 AM PST     Moonset
Fri -- 06:56 AM PST     1.14 feet Low Tide
Fri -- 07:16 AM PST     Sunrise
Fri -- 12:32 PM PST     Moonrise
Fri -- 01:12 PM PST     3.72 feet High Tide
Fri -- 05:18 PM PST     Sunset
Fri -- 09:20 PM PST     0.37 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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22.42.52.31.91.51.21.11.31.82.43.13.53.73.63.32.82.21.61.10.60.40.50.8

Tide / Current Tables for Brandt Bridge, San Joaquin River, California Current
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Brandt Bridge
Click for Map
Fri -- 01:36 AM PST     0.37 knots Max Flood
Fri -- 01:55 AM PST     Moonset
Fri -- 03:34 AM PST     -0.00 knots Slack
Fri -- 06:44 AM PST     -0.54 knots Max Ebb
Fri -- 07:16 AM PST     Sunrise
Fri -- 09:38 AM PST     0.00 knots Slack
Fri -- 12:26 PM PST     0.65 knots Max Flood
Fri -- 12:32 PM PST     Moonrise
Fri -- 03:23 PM PST     -0.00 knots Slack
Fri -- 05:17 PM PST     Sunset
Fri -- 07:55 PM PST     -1.02 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.20.30.40.2-0.1-0.4-0.5-0.5-0.4-0.20.10.50.60.60.50.1-0.3-0.6-0.8-1-1-0.9-0.7-0.4

Weather Map
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wmap_P
GEOS 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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Ground Weather Radar Station




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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 numerous 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.