Sunday, August25, 2019 L-36.com


Marine Weather and Tides
Portola Valley, CA

Version 3.4
NOTICE
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 6:31AMSunset 7:49PM Sunday August 25, 2019 9:12 AM PDT (16:12 UTC) Moonrise 12:16AMMoonset 3:10PM Illumination 24% Phase: Waning Crescent; Moon at 25 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 Coastal Waters From Pigeon Point To Point Pinos California Out To 10 Nm- 826 Am Pdt Sun Aug 25 2019
Today..W winds 5 to 10 kt. Wind waves 2 to 3 ft. Mixed swell W 2 to 4 ft at 12 seconds and S around 2 ft at 14 seconds.
Tonight..NW winds around 5 kt. Wind waves 1 to 2 ft. NW swell 3 to 5 ft at 12 seconds and S around 2 ft at 14 seconds.
Mon..W winds 5 to 10 kt. NW swell 3 to 5 ft at 11 seconds and S around 2 ft at 13 seconds.
Mon night..NW winds 5 to 10 kt. NW swell 3 to 5 ft at 11 seconds and S around 2 ft at 13 seconds.
Tue..NW winds 5 to 10 kt. Mixed swell nw 2 to 3 ft at 10 seconds and S around 2 ft at 13 seconds.
Tue night..NW winds 5 to 10 kt. NW swell 2 to 4 ft at 10 seconds.
Wed..W winds 10 to 15 kt. Mixed swell nw 2 to 4 ft and S around 2 ft.
Thu..NW winds 15 to 20 kt. Wind waves 1 to 2 ft. Mixed swell nw 2 to 3 ft and S around 2 ft.
PZZ500 826 Am Pdt Sun Aug 25 2019
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Weakening high pressure over the eastern pacific will keep light winds over the coastal waters through early to mid next week. SEa breezes will develop in the afternoons and evenings over the san francisco bay to the delta. Southerly swell will increase to 2 to 3 feet today and persist through early next week as a tropical system west of the baja peninsula progresses northward. Additionally, light to moderate northwest swell will continue through the period.


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 251130
afdmtr
area forecast discussion
national weather service san francisco bay area
430 am pdt Sun aug 25 2019

Synopsis High pressure will produce warmer temperatures through
early next week, especially across inland areas where very warm
temperatures are forecast. The marine layer will persist along the
coast, along with light onshore flow, resulting in relatively
mild temperatures near the ocean and bays. Moisture from tropical
storm ivo may pass across our area from Tuesday afternoon into
Wednesday, bringing increasing clouds and higher humidity. Cooler
temperatures are forecast for the second half of next week.

Discussion As of 3:12 am pdt Sunday... Overnight satellite
imagery indicates the marine layer has filled in nicely along the
coast and locally inland, especially the salinas valley. Fort ord
profiler indicates the depth is near 1,000 feet, which is a tad
more compressed compare to 24 hours. The shallower marine layer
has also led to some patchy fog this morning. Automated sensors
are bay area airports put the visibility at 2-5 miles. It's
possible that some patchy dense fog may develop between now and
sunrise.

No major change from the previous forecast. The large scale
synoptic pattern continues to be dominated by a large area of high
pressure currently over the eastern pacific extending eastward in
california. A trace of 500 mb heights over the bay area indicate a
rise in heights through at least Monday. This makes sense given
the slight compression of the marine layer and expected warm up
today and tomorrow. Given the more compressed marine layer
erosion of clouds back to the coast today will be earlier than
Saturday morning. Earlier clearing of clouds today, building 500
mb heights and warming 850 mb temperatures will all contribute to
warmer temperatures today. MAX temps today are forecast to be in
the 60s and 70s along the coast, 70s and 80s bay shoreline, and
90s to lower 100s interior. A shallow marine layer will once
again be possible Sunday night into Monday. An additional few
degrees of warming will be possible on Monday. High temperatures
will be above normal for Sunday and Monday, but heat risk
potential will be minimal thanks to some weak onshore flow and
some cooling at night.

All focus then turns toward tropical depression ivo currently
moving northward off the baja coast. Latest forecast keeps ivo
tracking northward into less than favorable conditions. Therefore,
ivo will ultimately become a remnant low later today or tonight.

Why is this important for the bay area? For several days now
models bring the leftover tropical moisture northward, which could
impact ca with thunderstorms. The real question is the exact track
of said tropical moisture. The 00z models keep the best moisture
and instability over the offshore waters before moving inland
ca or Tuesday into Wednesday. Therefore, will not mention any
convection in the forecast, but more likely higher dewpoints and
upper level clouds. There is definitely some bust potential as a
slight eastward shift would bring the possibility of
thunderstorms inland, which would be bad from a fire weather stand
point. Needless to say, this will be watched closely.

500 mb heights will lower by mid-week and into next weekend.

Therefore temperatures will cool and return to more seasonable
levels for late august.

Aviation As of 04:30 am pdt Sunday... For 12z tafs. Conditions
vary across the region this morning fromVFR at klvk to lifr at
ksts and kmry due to a mix of stratus and fog. Satellite imagery
shows stratus along the coast, over the bays, and down the
salinas valley as the marine layer sits at around 1000 ft agl per
the fort ord profiler. Ifr lifr conditions to prevail for most
sites this morning until ~16z-18z. Given a more compressed marine
layer compared to yesterday also expecting earlier clearing.VFR
conditions this afternoon and evening before patchy stratus and
potentially fog return overnight tonight. Light winds this morning
to increase and turn onshore this afternoon 10-15 kt with
occasional higher gusts possible.

Vicinity of ksfo... Satellite shows stratus filling in over the bay
and around the terminal. Ifr CIGS possible through 16z-17z.VFR
conditions this afternoon and evening. Patchy stratus to return
overnight. W to NW winds around 10 kt this morning increasing to
15 kt this afternoon.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... Vlifr-ifr conditions due to low CIGS and
patchy fog through 16z-18z.VFR conditions this afternoon before
ifr CIGS potentially return early this evening. Onshore winds this
afternoon 10-15 kt.

Marine As of 02:44 am pdt Sunday... Weakening high pressure
over the eastern pacific will keep light winds over the coastal
waters through early to mid next week. Sea breezes will develop in
the afternoons and evenings over the san francisco bay to the
delta. Southerly swell will increase to 2 to 3 feet today and
persist through early next week as a tropical system west of the
baja peninsula progresses northward. Additionally, light to
moderate northwest swell will continue through the period.

Mtr watches warnings advisories
Tday None.

Public forecast: mm
aviation: as
marine: as
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 mi55 min WNW 2.9 G 4.1 63°F 75°F1016.9 hPa
AAMC1 - 9414750 - Alameda, CA 29 mi61 min W 2.9 G 5.1 60°F 71°F1016.9 hPa
LNDC1 30 mi55 min WSW 2.9 G 4.1 61°F 1016.4 hPa
OBXC1 31 mi55 min 59°F 59°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 31 mi55 min WSW 2.9 G 7 58°F 1015.5 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 31 mi61 min WSW 1 G 2.9
OKXC1 - 9414776 - Oakland (Berth 34), CA 32 mi55 min WNW 1 G 2.9 58°F 1016.5 hPa
PXSC1 32 mi55 min 60°F 60°F
FTPC1 - 9414290 - San Francisco, CA 33 mi61 min Calm G 5.1 58°F 64°F1016.7 hPa
46237 - San Francisco Bar, CA (142) 36 mi43 min 61°F3 ft
PPXC1 - 9414847 - Richmond (Point Potrero), CA 38 mi61 min S 4.1 G 6 61°F 1016.6 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 39 mi50 min NNE 1.9 64°F 1017 hPa
RCMC1 - 9414863 - Richmond, CA 40 mi55 min 67°F
46042 - MONTEREY - 27NM West of Monterey Bay, CA 41 mi83 min 5.8 G 7.8 58°F 62°F4 ft1015.7 hPa (+1.0)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 42 mi33 min Calm G 1.9 58°F 60°F1017.1 hPa
46092 - MBM1 43 mi63 min NW 5.8 57°F 58°F1016.4 hPa (+1.4)
46114 - West Monterey Bay, CA 44 mi43 min 62°F4 ft
MLSC1 - Moss Landing, South Harbor, CA 45 mi33 min NW 1 G 2.9 58°F 1017 hPa58°F
ELXC1 - Elkhorn Slough Reserve, CA 46 mi88 min SSE 1.9 58°F 1015 hPa58°F
MZXC1 - 9415102 - Martinez-Amorco CA 47 mi61 min WNW 14 G 15 62°F 72°F1015.7 hPa
UPBC1 47 mi55 min WNW 9.9 G 16
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 48 mi55 min W 7 G 8.9 61°F 1015.9 hPa
PCOC1 - 9415144 - Port Chicago, CA 49 mi55 min W 15 G 19 64°F 71°F1015.6 hPa

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
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
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
Last
24hr
N3
N6
G9
N8
G12
NW12
NW9
G13
N9
G13
NW12
N12
NW12
G16
NW10
G13
NW8
G11
NW7
NW8
NW6
NW6
NW3
NW3
W4
NW3
W3
W4
NW3
NW3
NW2
1 day
ago
NW2
NW6
G10
NW9
G12
NW13
G16
NW14
N8
G13
NW13
G16
NW17
NW6
NW8
NW10
N6
G9
N3
--
W3
NW3
N1
S1
W1
W4
NW4
NW1
N2
NE2
2 days
ago
N3
N4
N4
G7
NW7
G11
N10
G14
N10
G13
NW14
W16
NW12
G16
NW14
G17
NW10
G13
NW9
G12
NW6
NW4
G7
NW3
NW2
S1
NW3
N3
NW3
NW4
NW3
--
N2

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Palo Alto Airport, CA10 mi26 minN 06.00 miOvercast with Haze64°F60°F88%1016.6 hPa
Mountain View, Moffett Field, CA11 mi17 minN 08.00 miOvercast66°F61°F84%1016.7 hPa
San Carlos Airport, CA12 mi26 minNNE 36.00 miFog/Mist64°F60°F88%1016.9 hPa
San Jose, San Jose International Airport, CA16 mi20 minN 48.00 miMostly Cloudy67°F62°F84%1016.2 hPa
Half Moon Bay Airport, CA18 mi18 minNW 30.75 miFog/Mist57°F57°F100%1016.9 hPa
San Francisco, San Francisco International Airport, CA19 mi17 minWNW 38.00 miMostly Cloudy62°F57°F84%1016.3 hPa
Hayward, Hayward Air Terminal, CA22 mi19 minN 06.00 miFog/Mist63°F60°F90%1017.3 hPa
San Jose / Reid / Hillv, CA22 mi26 minWSW 38.00 miClear68°F60°F78%1016.6 hPa
Oakland, Metro Oakland International Airport, CA23 mi20 minW 53.00 miFog/Mist63°F59°F87%1016.6 hPa

Link to 5 minute data for KPAO

Wind History from PAO (wind in knots)
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
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
Last 24hr--N6----NW10NW11------NW9NW9NW7------------------CalmCalmCalm
1 day agoN4N7N9N10NW12NW11N12N15NW15N14NW9NW9------------------CalmNE5N4
2 days ago------NW8N12NW12NW14----NW15N9NW7------------------CalmCalmN4

Tide / Current Tables for Palo Alto Yacht Harbor, California
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Palo Alto Yacht Harbor
Click for Map
Sun -- 01:15 AM PDT     Moonrise
Sun -- 04:01 AM PDT     0.60 feet Low Tide
Sun -- 06:32 AM PDT     Sunrise
Sun -- 09:35 AM PDT     6.35 feet High Tide
Sun -- 04:09 PM PDT     Moonset
Sun -- 04:14 PM PDT     3.36 feet Low Tide
Sun -- 07:47 PM PDT     Sunset
Sun -- 09:17 PM PDT     8.62 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
10
pm
11
pm
4.43.1210.612.345.46.26.35.95.44.94.43.83.43.64.66.27.88.68.47.3

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
Sun -- 12:14 AM PDT     -1.09 knots Max Ebb
Sun -- 01:15 AM PDT     Moonrise
Sun -- 03:58 AM PDT     0.00 knots Slack
Sun -- 06:32 AM PDT     Sunrise
Sun -- 07:07 AM PDT     1.23 knots Max Flood
Sun -- 10:23 AM PDT     -0.01 knots Slack
Sun -- 12:51 PM PDT     -0.48 knots Max Ebb
Sun -- 03:36 PM PDT     0.00 knots Slack
Sun -- 04:09 PM PDT     Moonset
Sun -- 06:44 PM PDT     0.98 knots Max Flood
Sun -- 07:47 PM PDT     Sunset
Sun -- 09:23 PM PDT     -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
10
pm
11
pm
-1.1-1-0.7-0.400.61.11.21.10.80.3-0.2-0.4-0.5-0.3-0.10.10.60.910.70.2-0.2-0.6

Weather Map and Satellite Images
       (on/off)   HelpWeather Map
wmap_P
GOES 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
Wind Forecast for San Francisco/Monterey Bay Area, CA (12,3,4,5)
      (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.