Tuesday, August20, 2019 L-36.com


Marine Weather and Tides
Muir Beach, 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 6:28AMSunset 7:57PM Tuesday August 20, 2019 9:56 AM PDT (16:56 UTC) Moonrise 9:54PMMoonset 10:09AM Illumination 74% Phase: Waning Gibbous; Moon at 20 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
PZZ545 Coastal Waters From Point Reyes To Pigeon Point California Out To 10 Nm- 813 Am Pdt Tue Aug 20 2019
Today..NW winds 10 to 15 kt, becoming W 15 to 20 kt this afternoon. Wind waves 3 to 4 ft this morning. W swell 2 to 4 ft at 12 seconds.
Tonight..NW winds 10 to 20 kt with gusts up to 25 kt. NW swell 2 to 4 ft at 10 seconds. Patchy fog.
Wed..NW winds 10 to 20 kt with gusts up to 25 kt. Wind waves 2 to 3 ft. W swell 3 to 5 ft at 14 seconds. Patchy fog.
Wed night..NW winds 15 to 20 kt with gusts up to 30 kt. Wind waves 3 to 4 ft. W swell 4 to 6 ft at 12 seconds. Patchy fog.
Thu..NW winds 10 to 20 kt with gusts up to 25 kt. Wind waves 2 to 3 ft. W swell 5 to 7 ft at 10 seconds and sw around 2 ft at 20 seconds. Patchy fog.
Thu night..W winds 10 to 15 kt. W swell 5 to 7 ft at 9 seconds and sw around 2 ft at 18 seconds. Patchy fog.
Fri..SW winds 10 to 15 kt. W swell 4 to 6 ft and sw around 2 ft. Patchy fog.
Sat..NW winds 5 to 10 kt. NW swell 2 to 4 ft and sw around 2 ft. Patchy fog.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...seas 5 to 7 ft with a dominant period of 10 seconds. Across the bar...seas 6 to 8 ft with a dominant period of 10 seconds. Maximum ebb current of 2.0 kt at 08:19 am Tuesday and 2.0 kt at 08:31 pm Tuesday.
PZZ500 813 Am Pdt Tue Aug 20 2019
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Generally light to moderate northwesterly winds will continue over the coastal waters through mid-week as high pressure sits over the eastern pacific. Locally gusty coastal jets are expected south of point arena, pigeon point, and point sur that will create hazardous seas conditions for smaller vessels. Breezy afternoon and evening winds are also forecast over the san francisco bay around the golden gate and through the delta as well as over the Monterey bay. Mixed seas will continue with shorter period northwest waves at around 8 to 10 seconds, a light longer period west swell, and a light southerly swell.


7 Day Forecast for Marine Location Near Muir Beach, CA
   Hourly   EDIT   Help
location: 37.78, -122.67     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus66 kmtr 201444 cca
afdmtr
area forecast discussion
national weather service san francisco bay area
740 am pdt Tue aug 20 2019

Synopsis A warming trend is forecast through Thursday as high
pressure builds over central and southern california. Inland areas
will see less in the way of night and morning low clouds as the
marine layer compresses. Seasonable temperatures are forecast
through the upcoming weekend, along with continued dry
conditions.

Discussion As of 07:40 am pdt Tuesday... The base of an
advancing 546dm 500mb low pressure trough offshore of the pacific
northwest has temporarily lowered heights aloft and allowed the
marine layer to deepen slightly versus yesterday morning (2600 ft
vs 2200 ft on 12z koak sounding). The fort ord profiler shows
less of a day over day change as it is farther southward from the
trough. As a result, the marine layer is inundating most inland
areas approx 2500 ft and below. Above the marine layer, a
warm dry air mass looms in response to a retrograding ridge
backing westward over the southern half of california. This high
pressure ridge will become the dominate synoptic scale feature
midweek and result in tomorrow (Wednesday) being the warmest day
of the next few. Temperatures tomorrow will range from near normal
along the shorelines to up to 10 degrees above normal for the
inland areas. Afternoon highs of 60s to low 70s are forecast along
the coast, upper 70s to upper 80s for areas in some proximity to a
coast shoreline, and into the low to mid 90s for the extreme
inland areas far from the coast.

A few reports of coastal drizzle came in this morning, but
otherwise, the current (overnight) forecast looks on track and no
updates are planned until the afternoon package. The main forecast
challenges today are determining if how much onshore flow will cool
temperatures Thursday and what impacts, if any, the remnants of a
tropical system may have across our area early next week. See
previous discussion for more information on the current forecast.

Previous discussion As of 3:35 am pdt Tuesday... Our weather
during the past few days was primarily influenced by a deep marine
layer, resulting in widespread night and morning low clouds,
local drizzle, and cooler than normal inland temperatures. The
first sign that the pattern is changing is evident early this
morning with the fort ord profiler indicating a decrease in the
depth of the marine layer as an upper ridge over the southern
plains and desert southwest begins to build to the west and across
southern california. In addition, light southerly low level flow
over the weekend is changing to a more typical west and northwest
direction. The building ridge and more typical wind patterns will
result in a warming trend across our region through Thursday.

Satellite currently shows an upper trough offshore along 140w.

The models track this trough inland across the pacific northwest
on Wednesday, but the trough is expected to remain too far north
of our area to have an impact on our weather. In fact, the models
agree that the biggest increase in temperatures during the
upcoming warming trend will occur on Wednesday. Temperatures are
forecast to warm slightly above normal by Wednesday when low to
mid 90s will be common in the inland valleys. Persistent light
onshore flow will keep coastal temperatures seasonably mild.

As the marine layer compresses over the next few days, expect
decreasing night and morning low clouds across inland areas, while
patchy fog is likely to develop near the ocean.

Models forecast a continued gradual increase in h5 heights late
in the week and through the weekend as the upper ridge continues
to build over california. However, both the GFS and ECMWF indicate
the warming trend will stall on Friday, and even reverse in some
areas with slight cooling forecast from Friday into the weekend.

The likely reason for this counterintuitive temperature trend
during the extended forecast period is the development of a weak
surface trough off the california coast which will turn surface
winds to a southerly direction by Friday. This southerly flow
will more readily transport marine air inland, especially in
places like the north bay valleys and santa cruz county. Forecast
temperatures from Friday through Sunday have been reduced below
the nbm values and brought more in line with the GFS and ECMWF mos
guidance.

One wildcard late in the extended period is the possibility of
tropical moisture reaching our area during the first half of next
week. Longer range models track a weak tropical system near the
west coast of mexico to the northwest and to a position off the
coast of the baja peninsula by the upcoming weekend. Moisture
from this system could then be drawn north and across california
sometime early next week. In fact, the 00z GFS develops
precipitation over our area by next Tuesday night. There is still
a great deal of uncertainty as to how this scenario will play out
and any potential impacts in our area are currently at the end of,
or just beyond, our extended forecast period. But this is
something that will need to be monitored closely over the next few
days.

Aviation As of 4:39 am pdt Tuesday... For 12z tafs. Widespread
stratus under a 3000 ft marine layer has brought MVFR to localized
lifr CIGS to area terminals this morning. Low clouds are forecast
to scatter out between 17z-22z today depending on location. See
tafs for more details. Light onshore flow around 5 to 10 kt will
persist through the morning hours becoming moderate and gusty
around 10 to 15 kt in the afternoon. Gusts to 25 kt possible over
ksfo.

Vicinity of ksfo... MVFR CIGS will prevail through the morning
hours with clearing anticipated around 18z-22z today. West winds
of around 10 kt will prevail overnight becoming moderate and
gusty around 10 to 15 kt in the afternoon with gusts to 25 kt
possible over ksfo.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... MVFR to ifr CIGS will persist through
the morning with clearing is anticipated around 18z-20z today.

West winds of around 5 kt will prevail through the morning then
increasing to 10 to 15 kt in the afternoon.

Marine As of 3:00 am pdt Tuesday... High pressure over the
eastern pacific will maintain generally light to moderate
northwesterly winds over the coastal waters through mid-week.

Locally gusty coastal jets south of point arena, pigeon point and
point sur will create hazardous conditions for small vessels.

Breezy winds are also forecast for san francisco bay around the
golden gate and through the delta, and over the monterey bay.

Mixed seas will continue with shorter period northwest waves at
around 8 to 10 seconds, a light longer period west swell, and a
light southerly swell.

Mtr watches warnings advisories
Tday Sca... Sf bay from 12 pm
sca... Mry bay from 12 pm
sca... Pt arena to pt reyes 0-10 nm from 12 pm
sca... Pigeon pt to pt pinos 0-10 nm from 12 pm
sca... Pt pinos to pt piedras blancas 0-10 nm
public forecast: drp dykema
aviation: cw
marine: 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
46237 - San Francisco Bar, CA (142) 2 mi56 min 60°F3 ft
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 9 mi46 min W 5.8 G 5.8 59°F 58°F1017.9 hPa
FTPC1 - 9414290 - San Francisco, CA 11 mi62 min WSW 5.1 G 9.9 60°F 61°F1017.3 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 14 mi51 min SE 5.1 61°F 1017 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 15 mi68 min NW 5.1 G 8 61°F 1015.9 hPa
PXSC1 15 mi62 min 62°F 59°F
RCMC1 - 9414863 - Richmond, CA 17 mi62 min WSW 2.9 G 6 62°F 65°F1016.8 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 18 mi62 min WNW 5.1 G 8
OBXC1 18 mi62 min 62°F 60°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 18 mi62 min NW 5.1 G 7 61°F 1017 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 18 mi80 min W 1 G 4.1 63°F 1016.9 hPa
AAMC1 - 9414750 - Alameda, CA 20 mi62 min W 6 G 8.9 62°F 69°F1017.5 hPa
LNDC1 21 mi62 min W 2.9 G 7 61°F 1017 hPa
PRYC1 - 9415020 - Point Reyes, CA 22 mi62 min 58°F1017.1 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 29 mi68 min WNW 8.9 G 11 62°F 1016.1 hPa
RTYC1 - 9414523 - Redwood City, CA 31 mi62 min W 6 G 9.9 64°F 75°F1017.8 hPa
UPBC1 34 mi68 min W 9.9 G 15
MZXC1 - 9415102 - Martinez-Amorco CA 34 mi62 min WSW 11 G 14 62°F 71°F1016.5 hPa
PCOC1 - 9415144 - Port Chicago, CA 38 mi62 min SW 12 G 16 62°F 72°F1016.3 hPa
46214 - Point Reyes, CA (029) 44 mi56 min 57°F4 ft
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 45 mi62 min WNW 13 G 17 65°F 1015.2 hPa
SFXC1 - San Francisco Bay Reserve, CA 45 mi71 min WNW 12 62°F 1016 hPa59°F
46013 - Bodega Bay - 48NM North Northwest of San Francisco, CA 46 mi46 min NW 5.8 G 7.8 53°F1017.2 hPa

Wind History for San Francisco, 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
W4
G8
SW5
G8
SW9
G14
SW7
G10
W7
G13
W5
G13
W8
G16
SW10
G18
SW9
G18
W6
G15
W5
G8
SW4
G9
SW6
G11
SW9
G12
SW4
G11
W9
G12
W7
G13
SW4
G9
SW2
G7
SW6
G10
W9
G13
W5
G9
W4
G8
SW4
G8
1 day
ago
SW8
G11
SW9
G12
SW13
G17
SW11
G19
SW11
G19
SW14
G21
SW13
G21
W12
G16
SW11
G18
SW12
G17
SW11
G19
SW12
G17
SW11
G16
SW8
G12
SW8
G11
W6
G12
SW5
G10
SW5
G8
SW5
G8
SW4
SW3
SW3
W3
SW6
G10
2 days
ago
SW8
G15
SW9
G19
SW11
G19
SW10
G17
W14
G21
W8
G18
SW13
G20
SW9
G17
SW8
G16
SW5
G16
W5
G15
W15
G20
W9
G14
SW8
G14
SW10
G15
SW9
G15
SW6
G9
SW1
SW2
SW3
S2
S3
SW5
G8
W5

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Francisco, San Francisco International Airport, CA20 mi2 hrsW 810.00 miOvercast65°F55°F70%1016.6 hPa
Half Moon Bay Airport, CA21 mi2 hrsNW 410.00 miOvercast61°F57°F88%1017.3 hPa
Oakland, Metro Oakland International Airport, CA24 mi2.1 hrsW 910.00 miOvercast64°F55°F73%1016.7 hPa

Link to 5 minute data for KSFO

Wind History from SFO (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 24hrSW8SW9SW12--SW10W18W16W16
G21
W14
G19
W10--------W11--W11--W9W7W11W11W8W10
1 day agoNE6NE6E6S12
G20
S12S15SW16SW19
G24
SW9
G18
S4--------SW6----SW4SW7W7--W6--SW5
2 days agoNE6S8S11S12S14SW11SW13
G20
W7S9S12S6S9S10S9S7--S12S6S6S8--S6S9E4

Tide / Current Tables for San Francisco Bar, California
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
San Francisco Bar
Click for Map
Tue -- 02:19 AM PDT     4.58 feet High Tide
Tue -- 06:30 AM PDT     Sunrise
Tue -- 08:26 AM PDT     1.26 feet Low Tide
Tue -- 11:08 AM PDT     Moonset
Tue -- 03:09 PM PDT     5.07 feet High Tide
Tue -- 07:56 PM PDT     Sunset
Tue -- 09:10 PM PDT     1.95 feet Low Tide
Tue -- 10:53 PM PDT     Moonrise
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
3.74.34.64.543.32.41.71.31.31.82.53.34.14.85.14.94.43.62.82.222.12.4

Tide / Current Tables for South Channel, San Francisco Bay Approach, California Current
   EDIT      (on/off)   Help   One Week of Data
South Channel
Click for Map
Tue -- 12:31 AM PDT     0.97 knots Max Flood
Tue -- 03:51 AM PDT     -0.00 knots Slack
Tue -- 06:29 AM PDT     Sunrise
Tue -- 06:44 AM PDT     -1.31 knots Max Ebb
Tue -- 09:47 AM PDT     0.00 knots Slack
Tue -- 11:08 AM PDT     Moonset
Tue -- 12:53 PM PDT     1.08 knots Max Flood
Tue -- 04:24 PM PDT     -0.00 knots Slack
Tue -- 07:12 PM PDT     -1.28 knots Max Ebb
Tue -- 07:56 PM PDT     Sunset
Tue -- 10:27 PM PDT     0.00 knots Slack
Tue -- 10:52 PM PDT     Moonrise
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
0.90.90.70.4-0.1-0.7-1.2-1.3-0.9-0.40.10.611.10.90.60.2-0.4-0.9-1.3-1.1-0.7-0.20.2

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.