Friday, September20, 2019 L-36.com


Marine Weather and Tides
Cupertino, CA

Version 3.4
NOTICE
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.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 6:53AMSunset 7:09PM Friday September 20, 2019 1:09 PM PDT (20:09 UTC) Moonrise 10:10PMMoonset 11:57AM Illumination 58% Phase: Waning Gibbous; Moon at 21 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- 850 Am Pdt Fri Sep 20 2019
Today..NW winds 5 to 15 kt. NW swell 5 to 7 ft at 10 seconds and S around 2 ft at 17 seconds.
Tonight..NW winds 5 to 15 kt. NW swell 6 to 8 ft at 10 seconds and S around 2 ft at 17 seconds.
Sat..NW winds 5 to 15 kt. NW swell 5 to 6 ft at 10 seconds and S around 2 ft at 17 seconds.
Sat night..NW winds 5 to 15 kt. NW swell 5 to 7 ft at 10 seconds and sw around 2 ft at 19 seconds.
Sun..NW winds 10 to 20 kt with gusts up to 30 kt. NW swell 4 to 6 ft at 9 seconds and S around 2 ft at 19 seconds.
Sun night..NW winds 10 to 20 kt with gusts up to 25 kt. NW swell 4 to 6 ft at 11 seconds and S around 2 ft at 19 seconds.
Mon..NW winds 10 to 20 kt with gusts up to 25 kt. NW swell 5 to 7 ft and S around 2 ft.
Tue..NW winds 5 to 15 kt. NW swell 5 to 7 ft and S around 2 ft.
PZZ500 850 Am Pdt Fri Sep 20 2019
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Northwest winds ease today, becoming generally light along the coast north of point sur and locally moderate in the outer waters and along the big sur coast. For Saturday, generally light winds across the waters except locally moderate in the outer waters north of point reyes. Winds increase somewhat into Sunday. A 9 to 11 second northwest swell will be the predominate wave in the waters today, with locally hazardous steep fresh swell. A lighter long period southerly swell will also be mixed in.


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 201750
afdmtr
area forecast discussion
national weather service san francisco bay area
1050 am pdt Fri sep 20 2019

Synopsis A warming trend will begin on Friday and continue
through Saturday. A low pressure system moving southward to our
east early next week may create the potential for continued
warming temperatures, dry offshore flow and increased fire weather
concerns. A trough of low pressure will move through the region
late next week resulting in a big cooldown.

Discussion As of 9:39 am pdt Friday... Skies are clear across
most of the state, with area temperatures running several degrees
warmer than yesterday at this time with current temperatures
mainly in the 60s. High temperatures today are expected to be
generally in the 70s and 80s.

High pressure will continue to build over the area into the
weekend, but the ridge will flatten slightly limiting full
potential of warm up. MAX temperatures will increase another 3-5
degrees by Saturday with highs ranging from the 70s at the coast,
70s 80s bay shoreline, to the 80s to lower 90s interior. A few
patchy low clouds will be possible along the coast Saturday
morning.

From previous discussion A change in the longwave pattern
begins to unfold on Sunday as the ridge weakens and an upper level
trough moves in from the nw. The lower 500 mb and cooler airmass
will lead to a slight drop in temperatures for the northern half
of the bay area. Monterey san benito counties will hold steady. By
Sunday night the trough develops into an inside slider type of
pattern - generally dry and in the fall months can trigger hot
weather and fire weather concerns. It definitely appears that this
pattern shift will do all three: no precip, increase fire weather
concerns with offshore flow, and raise temperatures dramatically.

For fire weather concerns see fire weather below. Temperatures
will increase a tad on Monday for some locations, but the bigger
warm up will occur on Tuesday and Wednesday. A 597 dam high parked
off the west coast for Tuesday and Wednesday. To put this into
perspective the strength of the high for late september is roughly
2-3 std deviations above normal. Temperature anomalies during
this time period are impressive as well - 850mb temps approaching
22-23c or about 6 std deviations. Latest forecast point soundings
for koak put 850mb temps close to 22c, which compared to
climatology it is above the 90 percentile. So what does all of
this mean for the bay area? A late season warm up is forecast with
high temperatures well above normal. Highs on Tuesday and
Wednesday are forecast to be is forecast to build 70s 80s at the
coast, 80s bay shoreline and 90s to lower 100s interior. Thermal
belts will be in full effect at night as well thanks to warm
airmass and offshore flow. The hills will remain in the 60s and
70s at night. However, valley locations (more populated areas)
will see some minor relief at night. Said relief will limit heat
risk potential, but latest guidance does put interior locations in
the moderate risk for heat concerns.

Another pattern shift is then forecast on Thursday with a pretty
substantial drop in temperatures. 5-10 degree temperature drop is
forecast from Wednesday to Thursday as the ridge weakens and a
trough approaches from the nw. The strength of the low varies from
one model to the next, but all show an decent upper low. Further
cooling is then expected Friday and into next weekend. Interesting
to note that the pattern aloft GOES from anomalously above to
below in a matter of a few days. If the euro is to be believed
not only will it be colder, but possibly wet.

Stay tuned for this roller coaster ride of weather the next 7-10
days.

Aviation As of 10:51 am pdt Friday... For 18z tafs.VFR will
continue for the terminals through the TAF period. Air mass is dry
with no cloud development at the terminals. Onshore winds will
increase this afternoon and become locally breezy. For tonight,
light offshore flow will develop at several of the terminals. This
should continue to advect dry air into the area withVFR
prevailing through Saturday morning.

Vicinity of ksfo...VFR. Onshore winds becoming breezy 21-22z with
speeds around 15 kt. Light and variable winds overnight tonight.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR. Onshore winds this afternoon with
speeds around 10kt. Light east to southeast winds developing
overnight.

Fire weather As of 02:55 am pdt Friday... A quick look at energy
release component (erc) and 100 hour fuel values are both well
below normal for the region. The below normal readings are likely
in response to the recent rain and cool weather. A warming and
drying trend is on track to develop into the weekend. There is
even a brief period of offshore flow Friday night across the north
and east bay hills. Winds will be breezy with moderate to
possibly poor humidity recoveries Friday night. Not strong enough
or long enough to warrant any red flag warnings. What it may do
is help chip away at the low ercs and high 100 hour fuels. The
inside slider mentioned above will bring a more pronounced
offshore flow event Monday into Tuesday with poor overnight
humidity recovery and gusty winds in the hills. One potential
limiting factor is the actual offshore flow gradient. Models put
the wmc-sfo gradient at 7-8 mb, decent but not strong. If this
pattern holds true a fire weather watch may be in order over the
weekend. Climatologically this is the favored time of year for
offshore flow events and red flag warnings for wind rh in the bay
area. Taking a look at the bigger picture - far norcal has had a
few wetting rain events so fire season may be near the end to the
north. Socal - not so much and fire season will keep on going.

What about the bay area? Fuels have been below normal for much of
the summer and recent cool wet weather has kept them that way.

That being said, the recent wet weather wasn't wet enough to end
fire season. Therefore, we're not out of the woods yet and we
should remain weather fire aware through the fall season.

Marine As of 8:50 am pdt Friday... Northwest winds ease today,
becoming generally light along the coast north of point sur and
locally moderate in the outer waters and along the big sur coast.

For Saturday, generally light winds across the waters except
locally moderate in the outer waters north of point reyes. Winds
increase somewhat into Sunday. A 9 to 11 second northwest swell
will be the predominate wave in the waters today, with locally
hazardous steep fresh swell. A lighter long period southerly swell
will also be mixed in.

Mtr watches warnings advisories
Tday Sca... Pt arena to pigeon pt 10-60 nm
sca... Pt pinos to pt piedras blancas 0-10 nm from 3 pm
public forecast: sims
aviation: st
marine: st
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 16 mi58 min NW 1.9 G 5.1 74°F 72°F1015.4 hPa
AAMC1 - 9414750 - Alameda, CA 34 mi64 min SSW 4.1 G 5.1 68°F 68°F1015.4 hPa
LNDC1 36 mi58 min WSW 4.1 G 5.1 70°F 1014.9 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 37 mi52 min SSW 6 G 6
OBXC1 37 mi58 min 69°F 57°F
MLSC1 - Moss Landing, South Harbor, CA 38 mi31 min NW 8 G 24 62°F 1014.5 hPa57°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 38 mi58 min WSW 4.1 G 5.1 71°F 1014.9 hPa
PXSC1 38 mi58 min 68°F 58°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 38 mi52 min ESE 2.9 G 4.1 67°F 1013.9 hPa
ELXC1 - Elkhorn Slough Reserve, CA 38 mi85 min WNW 6 74°F 1014 hPa59°F
46092 - MBM1 39 mi59 min NW 7.8 58°F 58°F1014.6 hPa (+0.3)
46042 - MONTEREY - 27NM West of Monterey Bay, CA 40 mi80 min 5.8 G 7.8 59°F 60°F7 ft1014.5 hPa (+0.0)
FTPC1 - 9414290 - San Francisco, CA 40 mi64 min WNW 5.1 G 6 67°F 63°F1015.3 hPa
46114 - West Monterey Bay, CA 43 mi40 min 64°F6 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 44 mi52 min SSW 5.1 G 7 69°F 1015.2 hPa
46237 - San Francisco Bar, CA (142) 45 mi40 min 63°F3 ft
TIBC1 - Tiburon Pier, San Francisco Bay, CA 45 mi149 min SE 4.1 66°F 1015 hPa
RCMC1 - 9414863 - Richmond, CA 46 mi52 min 64°F
46240 - Cabrillo Point, Monterey Bay, CA (158) 48 mi40 min 59°F3 ft

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Jose, San Jose International Airport, CA8 mi17 minNNW 710.00 miA Few Clouds81°F48°F32%1013.9 hPa
Palo Alto Airport, CA12 mi23 minNNE 510.00 miClear79°F50°F37%1014.6 hPa
San Jose / Reid / Hillv, CA13 mi23 minWNW 710.00 miClear81°F48°F32%1014.2 hPa
San Carlos Airport, CA18 mi20 minN 310.00 miClear77°F48°F36%1014.9 hPa
Hayward, Hayward Air Terminal, CA24 mi16 minW 810.00 miFair76°F48°F37%1015.3 hPa

Link to 5 minute data for KNUQ

Wind History from NUQ (wind in knots)
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Last 24hr------------------------------------------------
1 day ago------------------------------------------------
2 days ago------------------------------------------------

Tide / Current Tables for Upper Guadalupe Slough, San Francisco Bay, California
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Upper Guadalupe Slough
Click for Map
Fri -- 12:07 AM PDT     1.08 feet Low Tide
Fri -- 06:09 AM PDT     6.81 feet High Tide
Fri -- 06:54 AM PDT     Sunrise
Fri -- 11:54 AM PDT     3.13 feet Low Tide
Fri -- 12:57 PM PDT     Moonset
Fri -- 05:22 PM PDT     8.99 feet High Tide
Fri -- 07:08 PM PDT     Sunset
Fri -- 11:09 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.11.52.53.95.36.36.86.66543.43.13.74.96.588.98.98.275.43.72.3

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
Fri -- 12:08 AM PDT     0.00 knots Slack
Fri -- 02:51 AM PDT     1.00 knots Max Flood
Fri -- 06:18 AM PDT     -0.00 knots Slack
Fri -- 06:54 AM PDT     Sunrise
Fri -- 10:09 AM PDT     -0.63 knots Max Ebb
Fri -- 11:48 AM PDT     0.00 knots Slack
Fri -- 12:57 PM PDT     Moonset
Fri -- 02:46 PM PDT     0.77 knots Max Flood
Fri -- 05:29 PM PDT     -0.00 knots Slack
Fri -- 07:08 PM PDT     Sunset
Fri -- 10:31 PM PDT     -1.10 knots Max Ebb
Fri -- 11:09 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.10.40.910.80.50.1-0.2-0.4-0.6-0.6-0.40.10.40.70.80.60.2-0.1-0.4-0.7-0.9-1.1-1

Weather Map
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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.
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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.