Thursday, August24, 2017 L-36.com


Marine Weather and Tides
Portola Valley, 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 6:32AMSunset 7:48PM Thursday August 24, 2017 3:28 AM PDT (10:28 UTC) Moonrise 8:34AMMoonset 8:49PM Illumination 5% Phase: Waxing Crescent; Moon at 2 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
    EDIT      (on/off)   Help
PZZ560 Pigeon Point To Point Pinos To 10 Nm- 234 Am Pdt Thu Aug 24 2017
.small craft advisory in effect from 9 am pdt this morning through this evening...
.small craft advisory in effect from Friday morning through Friday evening...
Today..NW winds 5 to 15 kt...increasing to 15 to 25 kt in the afternoon. Wind waves 3 to 5 ft. Mixed swell nw 3 ft at 11 seconds and S 3 ft at 12 seconds. Patchy fog in the morning.
Tonight..NW winds 15 to 25 kt...decreasing to 5 to 15 kt by midnight. Wind waves 2 to 4 ft. NW swell 3 ft at 12 seconds.
Fri..NW winds 5 to 15 kt...increasing to 15 to 25 kt in the afternoon. Wind waves 3 to 5 ft. NW swell 3 ft at 11 seconds.
Fri night..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. NW swell 3 to 4 ft at 11 seconds.
Sat..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. NW swell 3 to 5 ft at 9 seconds.
Sun..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft.
Mon..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 ft.
PZZ500 234 Am Pdt Thu Aug 24 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Moderate to strong northerly winds will further increase through the day for all coastal zones. Wind gusts may reach gale force at times. Expect these winds to persist over the waters through the end of the week. No significant long period swell is forecast through the rest of the week.

7 Day Forecast for Marine Location Near Portola Valley, CA
   Hourly   EDIT   Help
location: 37.36, -122.23     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus66 kmtr 240554
afdmtr
area forecast discussion
national weather service san francisco bay area
1054 pm pdt Wed aug 23 2017

Synopsis Not expecting much change in weather conditions heading
into Thursday as temperatures remain slightly below seasonal averages
with overnight and morning low clouds. A warming trend will then
begin Friday and extend into early next week as high pressure builds
over the region. By Sunday and Monday, very warm to hot daytime
temperatures will be possible across inland areas.

Discussion As of 8:03 pm pdt Wednesday... Summer onshore breezes
will usher stratus and fog inland tonight and Thursday morning. A
closed mid level and dry low that's been gently meandering south
to north off socal and the central coast will finally be moving
eastward as a trough upstream to the northwest moves closer toward
california. Marine layer moisture will tend to turn into patchy
drizzle on the immediate coastline tonight as outlined in the
grids zones. The 18z NAM indicates very light QPF amounts along
the coast tonight and Thursday morning, otherwise our typical
summer dry stretch will continue. Current forecast outlines a
gradual warming trend for late week as high pressure builds over
california coupled with a return of long-wave ridging. Forecast
looks good, for more details please visit the previous discussion
below.

Prev discussion As of 1:35 pm pdt Wednesday... A weak short-wave
trough and associated low pressure system remains off of the
central and southern california coast today. This has helped to
maintain a modest marine layer of around 1,500 feet in depth.

While low clouds will burn-off over inland areas and mainly
retreat to the coast, stratus will again return to coastal areas
and adjacent valleys overnight with the chance of patchy fog and
drizzle as the marine layer becomes more compressed. Little
overall change is forecast into Thursday afternoon with inland
temperatures remain on the cool side of normal while coastal areas
warm into the 60s and 70s.

The aforementioned trough is forecast to dissolve by Friday as high
pressure over the desert southwest builds westward. This will work
to further compress the marine layer and result in less widespread
cloud cover, especially across the inland valleys. In addition,
temperatures aloft will warm and bring about warmer temperatures
across inland areas. As the ridge strengthens aloft, surface
temperatures will continue to warm through the weekend with more
widespread 80s and 90s inland with our warmer locations likely to
exceed the 100 degree mark by Sunday. In addition, overnight lows
will not cool as much, especially in the hills where temperatures
may only cool into the 70s. With this, the threat for heat related
illnesses will increase by Sunday into Monday given the hot daytime
temperatures and limited overnight cooling. Meanwhile, coastal areas
will notice a warming trend yet will continue to benefit from the
cool onshore flow. Will closely monitor the need for any heat
related products heading into late week with regards to the
Sunday Monday timeframe.

The ridge looks to remain the dominate weather feature heading into
much of next week as well. With that said, the ridge does appear to
weaken slightly and shift a bit more inland by the middle of next
week. With this, do expect the peak heating to occur Sunday into
Monday with a slight cooling trend by the middle of next week.

Temperatures will likely rebound back closer to seasonal averages
along with continued dry weather conditions through the entire
forecast period.

Aviation As of 10:54 pm pdt Wednesday for 06z
tafs... Widespread coastal stratus has moved in through coastal
gaps and canyons under a 2000 ft marine layer. Clearing to the
coast is anticipated around 17z Thursday morning. Light winds.

Vicinity of ksfo... Borderline MVFR ifr CIGS and vsbys anticipated
to prevail through tonight. Light west winds will persist through
tonight.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... Ifr CIGS will prevail through tonight
with decreases vsbys overnight into the morning hours. Light
winds.

Marine As of 9:00 pm pdt Wednesday... Northerly winds will
continue to increase through the evening and overnight as high
pressure builds to the west. Expect these winds to persist over
the waters through the end of the week. No significant long period
swell is forecast through the rest of the week.

Mtr watches warnings advisories
Tday Sca... Mry bay from 9 am
sca... Pigeon pt to pt pinos 0-10 nm from 9 am
sca... Pt arena to pt reyes 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... Pt reyes to pigeon pt 0-10 nm
sca... Sf bay from 1 pm
public forecast: canepa
aviation: cw
marine: rowe cw
visit us at

Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 10 mi40 min WNW 1.9 G 4.1 62°F 73°F1012.7 hPa
AAMC1 - 9414750 - Alameda, CA 29 mi40 min SW 2.9 G 5.1 58°F 69°F1013.6 hPa
LNDC1 30 mi40 min S 5.1 G 8 59°F 1013.1 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 31 mi40 min E 1 G 7 57°F 1012 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 31 mi40 min SSW 8.9 G 11
OBXC1 31 mi40 min 58°F 58°F
PXSC1 32 mi40 min 59°F 58°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 32 mi40 min SW 5.1 G 7 58°F 1013.1 hPa
FTPC1 - 9414290 - San Francisco, CA 33 mi46 min S 2.9 G 8 57°F 62°F1013.2 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 35 mi38 min NW 16 G 18 61°F 60°F7 ft1013 hPa (-0.8)
46237 - San Francisco Bar, CA (142) 36 mi58 min 60°F5 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 38 mi40 min S 13 G 17 59°F 1013.1 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 39 mi41 min SE 2.9 57°F 1013 hPa
RCMC1 - 9414863 - Richmond, CA 40 mi46 min SSE 8 G 11 58°F 65°F1012.5 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi38 min NNW 14 G 16 60°F 61°F6 ft1013.5 hPa (-0.9)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 42 mi38 min NW 16 G 19 58°F 60°F6 ft1013.1 hPa (-0.5)
46092 - MBM1 43 mi83 min NNW 12 59°F 60°F1013.3 hPa (-1.0)
46114 - West Monterey Bay, CA 44 mi58 min 61°F5 ft
ELXC1 - Elkhorn Slough Reserve, CA 46 mi103 min S 1.9 58°F 1013 hPa57°F
MZXC1 - 9415102 - Martinez-Amorco CA 47 mi40 min W 9.9 G 12 60°F 69°F1012.1 hPa58°F
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 48 mi46 min WSW 9.9 G 15 60°F 1011.9 hPa
PCOC1 - 9415144 - Port Chicago, CA 49 mi40 min SW 9.9 G 12 59°F 69°F1011.6 hPa

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
Last
24hr
W4
NW4
S5
S2
NW5
G9
NW6
NW5
N2
NW3
N8
NW9
G12
N12
G16
N17
N16
N10
G14
N13
NW10
NW9
NW6
NW8
NW6
W4
W4
W4
1 day
ago
NW5
N4
N5
NW3
N3
NW3
N2
N4
G7
N6
G9
N7
N8
G13
NW10
NW14
NW13
NW13
NW11
NW12
NW9
NW7
G10
NW6
NW4
NW4
NW6
NW7
2 days
ago
S3
NW4
SW3
S2
S4
E1
NE5
N6
N9
N11
G14
N11
G15
NW11
NW10
G13
NW11
W10
NW11
NW7
S4
SE3
N6
NW7
NW6

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Mountain View, Moffett Field, CA11 mi92 minN 010.00 miOvercast63°F57°F84%1014 hPa
San Carlos Airport, CA12 mi38 minN 010.00 miMostly Cloudy59°F55°F88%1013.5 hPa
San Jose, San Jose International Airport, CA16 mi35 minN 07.00 miOvercast63°F59°F87%1013.3 hPa
Half Moon Bay Airport, CA18 mi53 minNW 35.00 miFog/Mist57°F57°F100%1012.9 hPa
San Francisco, San Francisco International Airport, CA19 mi92 minW 610.00 miMostly Cloudy60°F55°F86%1013.3 hPa
Hayward, Hayward Air Terminal, CA22 mi34 minWNW 510.00 miOvercast with Haze61°F55°F81%1013.9 hPa
Oakland, Metro Oakland International Airport, CA23 mi35 minWSW 510.00 miOvercast59°F57°F96%1013.1 hPa

Wind History from PAO (wind in knots)
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
Last 24hr------------------CalmCalmCalmCalm4--N9N9N9NW15NW15NW15NW15NW11N8
1 day ago------------------CalmCalmCalm5--N9N10N10N11N12N16NW15
G22
N18NW10NW10
2 days ago------------------455--5NE6--N11N12N17--N16N14NW10NW6

Tide / Current Tables for Granite Rock, Redwood Creek, San Francisco Bay, California
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Granite Rock
Click for Map
Thu -- 02:34 AM PDT     8.46 feet High Tide
Thu -- 06:32 AM PDT     Sunrise
Thu -- 09:19 AM PDT     0.30 feet Low Tide
Thu -- 09:33 AM PDT     Moonrise
Thu -- 03:32 PM PDT     8.16 feet High Tide
Thu -- 07:48 PM PDT     Sunset
Thu -- 09:45 PM PDT     1.49 feet Low Tide
Thu -- 09:49 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
5.47.18.38.47.66.24.32.410.30.61.73.45.26.988.17.35.84.12.61.71.52.3

Tide / Current Tables for Dumbarton Hwy Bridge, South San Francisco Bay, California Current
   EDIT      (on/off)   Help   One Week of Data
Dumbarton Hwy Bridge
Click for Map
Thu -- 12:35 AM PDT     1.78 knots Max Flood
Thu -- 03:25 AM PDT     -0.00 knots Slack
Thu -- 06:32 AM PDT     Sunrise
Thu -- 06:46 AM PDT     -1.34 knots Max Ebb
Thu -- 09:33 AM PDT     Moonrise
Thu -- 10:00 AM PDT     0.00 knots Slack
Thu -- 01:06 PM PDT     1.89 knots Max Flood
Thu -- 04:06 PM PDT     -0.00 knots Slack
Thu -- 07:13 PM PDT     -1.13 knots Max Ebb
Thu -- 07:48 PM PDT     Sunset
Thu -- 09:48 PM PDT     Moonset
Thu -- 10:21 PM PDT     0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.71.71.30.5-0.3-0.9-1.3-1.3-1.1-0.6-00.91.61.91.71.10.1-0.5-0.9-1.1-1-0.7-0.20.5

Weather Map and Satellite Images
       (on/off)   Help
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)
      (on/off)   Help

Ground Weather Radar Station San Francisco Bay Area, CA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.