Thursday, March30, 2017 L-36.com


Marine Weather and Tides
Cupertino, CA

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:53AMSunset 7:31PM Thursday March 30, 2017 3:50 AM PDT (10:50 UTC) Moonrise 7:56AMMoonset 9:44PM Illumination 9% 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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PZZ560 Pigeon Point To Point Pinos To 10 Nm- 214 Am Pdt Thu Mar 30 2017
.small craft advisory in effect through this afternoon...
.gale warning in effect from this afternoon through late tonight...
.small craft advisory in effect from Friday morning through Friday afternoon...
Today..NW winds 20 to 30 kt. Wind waves 3 to 5 ft. NW swell 9 to 12 ft at 14 seconds. Slight chance of showers in the morning.
Tonight..NW winds 20 to 30 kt. Wind waves 4 to 6 ft. NW swell 6 to 8 ft at 13 seconds.
Fri..NW winds 20 to 30 kt. Wind waves 3 to 5 ft. NW swell 11 to 12 ft at 11 seconds...shifting to the west 6 to 8 ft at 14 seconds in the afternoon.
Fri night..NW winds 20 to 30 kt. Wind waves 3 to 4 ft. NW swell 9 to 12 ft at 14 seconds.
Sat..NW winds 15 to 25 kt...decreasing to 5 to 15 kt. Wind waves 3 ft...becoming 2 ft or less. NW swell 8 to 10 ft at 16 seconds.
Sun..NW winds 20 to 30 kt. Wind waves 3 to 5 ft. NW swell 9 to 12 ft...increasing to 14 to 17 ft.
Mon..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. NW swell 11 to 14 ft.
PZZ500 214 Am Pdt Thu Mar 30 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... 0800z surface observations and bouy data depicted a cold front entering the northern portions of the coastal waters. Northwest winds behind this cold frontal passage will increase through the day today. Surface high pressure will build over far northern california into Friday resulting in gale force winds over the coastal waters beginning later this afternoon and continuing into Friday...and possibly later for the outer water zones. Northwest swell will level off while swell periods steadily decrease today. Large and very long period northwesterly swell will return to the coastal waters late Saturday night that will last through the weekend.

7 Day Forecast for Marine Location Near Cupertino, CA
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location: 37.31, -122.06     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 300552
afdmtr
area forecast discussion
national weather service san francisco bay area
1052 pm pdt Wed mar 29 2017

Synopsis Cooler and breezy conditions are forecast for
Thursday after a cold front sweeps through the region. This
system may produce isolated light showers from late tonight into
early Thursday morning, however most locations will not receive
measurable rainfall. Locally strong and gusty northwest winds are
likely from Thursday afternoon into Friday. A warming trend is
then expected for the upcoming weekend as high pressure rebuilds
over the region.

Discussion As of 9:05 pm pdt Wednesday... Evening satellite
imagery shows a cold front moving through northwest california.

Clouds have begun to increase over our area in advance of the cold
front - mostly high clouds but also patchy low clouds in coastal
areas. This cold front is expected to sweep southeast and through
our area late tonight and early Thursday morning. Models continue
to indicate that most precipitation with this system will fall to
our north and east. However, the 00z NAM continues to show widely
scattered light precipitation across our area starting around
midnight tonight and continuing until shortly after sunrise Friday
morning. Most other models also indicate at least a slight chance
of precipitation. In any event, where rain does fall, amounts are
expected to be very light. A cooler airmass will arrive behind
the incoming cold front and high temperatures on Thursday are
expected to be 5 to 10 degrees cooler than today.

The primary weather impact from this system will be locally strong
and gusty northerly winds in the post-frontal environment starting
tomorrow. Nw-se surface pressure gradients are expected to
quickly steepen on Thursday as high pressure builds off the
northern california coast and low pressure deepens over far
southern california and nevada. Initially, on Thursday, strongest
northwest winds will occur along the coast. Coastal winds are
expected to increase in the morning but not reach their peak
intensity until late Thursday afternoon and early Thursday
evening. Coastal winds will then subside by late Thursday
evening. But as winds decrease near the coast, north winds are
expected to increase in the hills and be locally strong and gusty
from late Thursday night through midday Friday. A wind advisory
has been issued for most coastal zones from noon through 8 pm
Thursday and for most mountain zones from midnight Thursday night
through midday Friday. Local wind gusts up to 45 mph are likely
near the coast late Thursday, and winds gusts up to 50 mph are
expected in the hills by late Thursday night. Winds will subside
gradually through Friday and Friday night, but locally breezy
conditions are expected to continue into Saturday morning, mainly
in the hills.

These northerly winds will bring a much drier airmass into our
region by Friday. The dry airmass will mean cool temperatures in
the valleys to start the day Friday, but also a quick warmup once
the Sun rises. An upper ridge will then build over california by
Saturday, allowing temperatures to warm several degrees by the
weekend. Our weekend is shaping up to be dry with seasonably warm
temperatures.

Temperatures will cool early next week another system drops in
from the northwest. The Monday system looks less likely to
produce any precipitation in our area, but will result in breezy
conditions once again by Monday afternoon.

From previous discussion... The longer range guidance continues to
show a return to wet weather conditions by late next week. The
models generally agree that a more potent weather system will drop
southward into northern california by Thursday or Friday of next
week with a moderate moisture tap. Both the GFS and ECMWF show
widespread rainfall across the region by next Friday. However,
being more than a week out, confidence remains low at this time
and changes to the forecast are likely.

Aviation As of 10:52 pm pdt Wednesday... Coastal stratus and
fog with a combination of ifr and MVFR CIGS reported this evening.

Primarily expecting an onshore wind flow tonight along with
pockets of light rain or drizzle developing. A cold front moves
through late tonight and Thursday morning first lifting then
eventually eroding the marine inversion followed by a steepening
northerly gradient and winds Thursday into Friday.VFR is likely
to return by mid-late Thursday morning, strong and gusty NW winds
coastal waters with some overlap onto land developing Thursday
afternoon and evening.

Vicinity of ksfo... MVFR cig developing tonight then lowering to
ifr cig in light drizzle or rain tonight with w-nw winds. Clearing
toVFR by 17z Thursday, strong and gusty w-nw winds Thursday
afternoon and evening.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... MVFR/ifr developing tonight with light
drizzle or rain developing later tonight into Thursday morning.

Vfr forecast to return by late Thursday morning, strong and gusty
w-nw winds Thursday afternoon and evening.

Marine As of 10:29 pm pdt Wednesday... Gusty northwest winds
will accompany a cold frontal passage later tonight through
Thursday morning. Surface high pressure will build over far
northern california Thursday into Friday resulting in gale force
winds over the coastal waters beginning later Thursday and continuing
into Friday. Northwest swell will level off while swell periods
steadily decrease tonight through Thursday. Large very long period
northwesterly swell will move into the coastal waters Saturday
evening into Sunday.

Mtr watches/warnings/advisories
Tngt 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
sca... Mry bay until 3 am
public forecast: dykema/rgass
aviation/marine: canepa
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 16 mi51 min SW 5.1 G 6 57°F 62°F1019.2 hPa (-1.1)
AAMC1 - 9414750 - Alameda, CA 34 mi51 min W 7 G 13 56°F 60°F1019.6 hPa (-1.4)
LNDC1 36 mi51 min W 8.9 G 11 57°F 1019.1 hPa (-1.4)
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 37 mi51 min W 14 G 17
OBXC1 37 mi51 min 56°F 56°F
PXSC1 38 mi51 min 56°F 55°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 38 mi51 min W 12 G 15 56°F 1019.1 hPa (-1.5)
46092 - MBM1 39 mi102 min WNW 12 55°F 55°F1019.3 hPa (-0.7)
FTPC1 - 9414290 - San Francisco, CA 40 mi51 min W 2.9 G 7 55°F 55°F1019.6 hPa (-1.2)
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi61 min 16 G 18 55°F 56°F11 ft1020.1 hPa (-1.0)
46114 - West Monterey Bay, CA 43 mi51 min 56°F11 ft
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 44 mi61 min WNW 12 G 16 55°F 56°F10 ft1019.9 hPa (-1.0)
PPXC1 - 9414847 - Richmond (Point Potrero), CA 44 mi51 min WNW 8.9 G 13 60°F 1019.1 hPa (-1.6)
46237 - San Francisco Bar, CA (142) 45 mi51 min 55°F9 ft
RCMC1 - 9414863 - Richmond, CA 46 mi51 min WNW 11 G 14 58°F 58°F1018.7 hPa (-1.3)
46240 - Cabrillo Point, Monterey Bay, CA (158) 48 mi60 min 58°F5 ft

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Mountain View, Moffett Field, CA8 mi55 minN 010.00 miOvercast57°F51°F81%1020.5 hPa
San Jose, San Jose International Airport, CA8 mi58 minN 010.00 miOvercast57°F51°F81%1019.8 hPa
San Carlos Airport, CA18 mi56 minW 310.00 miOvercast57°F53°F88%1020 hPa
Hayward, Hayward Air Terminal, CA24 mi57 minW 1110.00 miOvercast57°F52°F83%1020.5 hPa

Wind History from NUQ (wind in knots)
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Last 24hrCalmCalmSE3CalmCalmCalmCalmN5N8N15N14N15N15NE5N13NW7N7N7N5NE5CalmCalmS4Calm
1 day agoCalmCalmCalmCalmCalmW45NE3N7N8NW11
G19
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NW9NW7NW6E4CalmCalmCalmCalmCalmCalm
2 days agoCalmW43W5NW5W6NW8N11N13
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NW6NW6SW5W5W3W4W3

Tide / Current Tables for Upper Guadalupe Slough, San Francisco Bay, California
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Upper Guadalupe Slough
Click for Map
Thu -- 02:54 AM PDT     10.09 feet High Tide
Thu -- 06:55 AM PDT     Sunrise
Thu -- 08:55 AM PDT     Moonrise
Thu -- 10:03 AM PDT     -0.31 feet Low Tide
Thu -- 03:50 PM PDT     8.51 feet High Tide
Thu -- 07:29 PM PDT     Sunset
Thu -- 10:08 PM PDT     1.43 feet Low Tide
Thu -- 10:43 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
5.17.59.410.19.68.163.71.60.2-0.30.42.14.36.588.57.96.753.221.42

Tide / Current Tables for Dumbarton Point 2.3 mi NE, South San Francisco Bay, California Current
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Dumbarton Point 2.3 mi NE
Click for Map
Thu -- 12:01 AM PDT     1.44 knots Max Flood
Thu -- 03:01 AM PDT     -0.00 knots Slack
Thu -- 06:56 AM PDT     Sunrise
Thu -- 07:34 AM PDT     -1.47 knots Max Ebb
Thu -- 08:55 AM PDT     Moonrise
Thu -- 09:57 AM PDT     0.01 knots Slack
Thu -- 12:40 PM PDT     1.58 knots Max Flood
Thu -- 04:01 PM PDT     -0.01 knots Slack
Thu -- 07:29 PM PDT     Sunset
Thu -- 08:03 PM PDT     -1.07 knots Max Ebb
Thu -- 10:05 PM PDT     0.00 knots Slack
Thu -- 10:44 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.41.20.70-0.4-0.9-1.2-1.4-1.4-0.800.91.51.61.30.70-0.4-0.7-1-1.1-0.7-0.10.6

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 (6,6,7,8)
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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.