Wednesday, August21, 2019 L-36.com


Marine Weather and Tides
Montara, 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 6:29AMSunset 7:56PM Wednesday August 21, 2019 12:18 AM PDT (07:18 UTC) Moonrise 10:23PMMoonset 11:06AM Illumination 69% 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
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PZZ545 Coastal Waters From Point Reyes To Pigeon Point California Out To 10 Nm- 858 Pm Pdt Tue Aug 20 2019
Tonight..NW winds 10 to 20 kt with gusts up to 25 kt. NW swell 2 to 4 ft at 9 seconds.
Wed..NW winds 15 to 20 kt with gusts up to 25 kt. Wind waves 2 to 3 ft. W swell 2 to 4 ft at 14 seconds.
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 13 seconds.
Thu..NW winds 15 to 25 kt with gusts up to 30 kt. W swell 5 to 7 ft at 11 seconds and sw around 2 ft at 20 seconds.
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.
Fri..S winds 10 to 15 kt. W swell 5 to 7 ft at 10 seconds and sw around 2 ft at 18 seconds.
Fri night..SW winds 5 to 10 kt. W swell 3 to 5 ft at 10 seconds and sw around 2 ft at 16 seconds.
Sat..W winds 5 to 10 kt. Wind waves 2 to 3 ft. W swell 2 to 4 ft and sw around 2 ft.
Sun..W winds 5 to 10 kt. Wind waves 2 to 3 ft. W swell 2 to 3 ft and sw around 2 ft.
...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 08:31 pm Tuesday and 1.6 kt at 09:07 am Wednesday.
PZZ500 858 Pm 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... Light to moderate northwest winds will persist across the coastal waters through mid-week as high pressure sits over the eastern pacific and a surface low moves into western canada. Locally gusty coastal jets are forecast 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 Montara, CA
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location: 37.57, -122.58     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 210544
afdmtr
area forecast discussion
national weather service san francisco bay area
1044 pm 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 9:53 pm pdt Tuesday... No forecast updates
planned at the moment though current cloud coverage is currently
slightly less than originally anticipated. Synoptic pattern
features a fairly strong early season front approaching the oregon
coast overnight while the four-corners ridge is dominating the
pattern to our south. The bay area is stuck in between. Currently
there is only a 3 mb northerly gradient while the sfo to
sacramento onshore is about 2.5 mb. Some low clouds are already
starting to bank up across the east bay hills as well as along the
san mateo coast and down around monterey bay. In addition some
high clouds continue to pass to our north.

Its a little odd that at 500 mb we will be going into a
trough cyclonic flow over the next day or so (due to the front
well to our north). However near the surface we will see warming
as the 590 dm contour stays over the region and the southern
ridge remains stubborn. The boundary layer winds will turn more
northerly on weds which will induce some adiabatic warming. Model
guidance suggests many of the north and east bay valleys will warm
into the upper 80s and lower 90s on weds which will be as much as
10 degrees warmer than what was observed on Tuesday.

One item to watch on weds night is some potentially gusty
northerly winds in the hills. 00z NAM has 20-30 kt winds at 925 mb
(around 2500 feet) from sonoma to monterey late weds afternoon
into weds night. Not expecting any wind advisories but could be a
brief fire weather concern.

Pattern looks to continue with above normal warming trend for
inland areas Thursday and Friday as the ridge builds over the
region with potential for the thermal trough to straddle the coast
at times keeping marine stratus to a minimum. Long range trends
remain warm and dry. Will be watching the tropical activity as it
heads north from baja next week. Current ECMWF would bring
remnants of our coast by about next Thursday... A long ways off.

Prev discussion As of 02:30 pm pdt Tuesday... California is
positioned between two synoptic scale features early this
afternoon -- an advancing trough to the northwest and a
retrograding ridge to the southeast. Both of these features have
played a role in driving the local weather today with the
advancing trough encouraging a deeper marine layer overnight into
this morning and the retrograding ridge suppressing the marine
layer and forcing warmer temperatures and the mostly skies early
this afternoon. While the ridge has taken over as the dominate
feature early this afternoon, the advancing trough will wrest
control from the ridge, at least across the north bay, through the
remainder of the day as cooler, moister air mass advects inland from
the west. Latest satellite imagery shows scattered to broken high
clouds on the leading edge of this air mass boundary now shifting
inland across the mendocino coast and northward at this hour. Expect
to see some of these clouds spread into the north bay and parts of
the immediate bay area later this afternoon into the evening but
will probably arrive too late to drastically impact todays afternoon
high temperatures.

Forecast models have struggled with the specifics of what happens
next but generally agree that the ridge will deflect the advancing
trough northward into the pacnw extreme norcal after attempting to
invade the golden state.

For tonight, the marine layer will become suppressed by the
retrograding ridge across the central coast and parts of the bay
area but may instead mix out across the sonoma marin coastlines due
to the presence of the cooler air aloft in the advancing trough. As
such, would not be surprised to see patchy fog and periods of
drizzle along the coastline from the san mateo coastline southward
through big sur with fractured cloud decks across the north bay.

The long range forecast models then depict a steady rise in
atmospheric heights over the 7 plus days however that rise will
not necessarily dictate a steady rise in temperatures.

For tomorrow, the ridge will become the dominate player after the
trough has deflected to the north into the pacific northwest and
promote the warmest temperatures of this work week for most areas.

That said, the north bay high temperatures may somewhat lag behind
the rest of the forecast area tomorrow after a secondary vort
pulse within the broader parent trough over the pacnw forces it to
briefly dip back into northern california.

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. The marine layer should further
compress tomorrow night into Thursday morning which will allow
Thursday morning's temperatures to slightly outpace Wednesday's.

By the afternoon, Thursday temperatures will come into line with
Wednesdays readings though the north east bay should run slightly
warmer than the previous day given the absence of a trough on
their northern periphery.

500mb heights continue to increase into Friday as the ridge shifts
offshore and amplifies. Despite this, temperatures are forecast
to stall or even drop primarily due to a shift in wind direction
to the southwest. This shift in wind direction should increase
the onshore advection of cool, moist air to inland regions despite
the warmer air subsiding from aloft. A warming trend is then
expected through the weekend and into early next week with the
hottest temperatures anticipated to arrive early to mid next
week.

The one potential gotcha in the long range forecast is the
presence of a potential tropical disturbance (80-90% chance of
organization) currently off the southern coast of mexico. GFS euro
ensemble members give this system a roughly 33-40% chance of
moving into the broader vicinity of the sf monterey bay areas by
early next week, potentially introducing increased a wetter, more
unstable air mass underneath a broader high pressure ridge.

Needless to say, there remains a fair amount of uncertainty in the
forecast over the next week.

Aviation As of 10:45 pm pdt Tuesday... Ft ord profiler shows a
marine layer developing at around 1000 feet as the airmass aloft
warms. This is in response to an upper level ridge over the
southwest expanding westward into california. Stratus has been
slow to develop tonight as a light northerly flow has developed
over the area. There is a small area inside the bay which could
spread out into oak and sfo. Still expecting stratus to reform
along the coast later tonight with the marine layer but confidence
is not high as the northerly flow could keep clouds reduced. The
northerly flow will increase on Thursday so there is less of a
chance for stratus Wednesday night.

Vicinity of ksfo... MVFR CIGS after 12z with bases around 1500 ft
possibly as low as 1000 ft. Confidence is not high as it could
stayVFR. Any CIGS will clear out by 17z.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... MVFR ifr CIGS after 12z clearing after
17z.

Marine As of 10:31 pm pdt Tuesday... Light to moderate northwest
winds will persist across the coastal waters through mid-week as
high pressure sits over the eastern pacific and a surface low
moves into western canada. Locally gusty coastal jets are
forecast 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.

Mtr watches warnings advisories
Tngt Sca... Pt arena to pt reyes 0-10 nm
sca... Pt pinos to pt piedras blancas 0-10 nm
public forecast: rww
aviation: W pi
marine: W pi
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
46237 - San Francisco Bar, CA (142) 15 mi48 min 61°F3 ft
FTPC1 - 9414290 - San Francisco, CA 17 mi48 min SW 4.1 G 8.9 60°F 62°F1015.9 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 19 mi28 min NW 12 G 14 60°F 57°F4 ft1016.2 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 19 mi54 min SW 7 G 9.9 61°F 1014.4 hPa
PXSC1 19 mi48 min 62°F 58°F
AAMC1 - 9414750 - Alameda, CA 20 mi48 min W 6 G 8 63°F 70°F1016.2 hPa
RTYC1 - 9414523 - Redwood City, CA 20 mi48 min WSW 2.9 G 4.1 63°F 75°F1016.5 hPa
OBXC1 21 mi48 min 63°F 60°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 21 mi48 min WSW 6 G 8 62°F 1015.7 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 21 mi48 min W 9.9 G 11
LNDC1 22 mi48 min SSW 1.9 G 2.9 63°F 1015.7 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 23 mi31 min S 9.9 61°F 1015 hPa
RCMC1 - 9414863 - Richmond, CA 26 mi48 min S 5.1 G 7 63°F 67°F1015.3 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 26 mi54 min SSW 9.9 G 13 63°F 1015.7 hPa
PRYC1 - 9415020 - Point Reyes, CA 36 mi48 min 61°F1015.6 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 38 mi54 min SW 8 G 11 65°F 1014.5 hPa
UPBC1 40 mi54 min WNW 5.1 G 7
MZXC1 - 9415102 - Martinez-Amorco CA 40 mi48 min W 6 G 7 66°F 71°F1014.7 hPa
PCOC1 - 9415144 - Port Chicago, CA 44 mi48 min SSW 5.1 G 9.9 63°F 72°F1014.6 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 49 mi48 min WNW 12 G 17 68°F 1013.3 hPa

Wind History for San Francisco, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA6 mi23 minN 010.00 miPartly Cloudy55°F53°F94%1016.6 hPa
San Francisco, San Francisco International Airport, CA12 mi22 minWNW 910.00 miA Few Clouds61°F54°F78%1015.6 hPa
San Carlos Airport, CA18 mi3.5 hrsW 8 G 1610.00 miClear64°F55°F73%1016.3 hPa
Oakland, Metro Oakland International Airport, CA21 mi25 minN 010.00 miPartly Cloudy60°F55°F84%1015.8 hPa

Link to 5 minute data for KSFO

Wind History from SFO (wind in knots)
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1 day agoS7S6SW4SW7W7W6W6W5SW5SW8SW9SW12W9SW10W18W16W16
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2 days agoS8S12S6S6S8S5S6S9E4NE6NE6E6S12
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S4SW6S7S7S8SW6

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
Click for Map
Wed -- 02:41 AM PDT     4.08 feet High Tide
Wed -- 06:30 AM PDT     Sunrise
Wed -- 08:44 AM PDT     1.72 feet Low Tide
Wed -- 12:06 PM PDT     Moonset
Wed -- 03:13 PM PDT     5.04 feet High Tide
Wed -- 07:54 PM PDT     Sunset
Wed -- 09:48 PM PDT     1.74 feet Low Tide
Wed -- 11:22 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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3.13.744.13.83.32.72.21.81.722.63.34.14.754.94.53.72.92.31.81.72

Tide / Current Tables for South Channel, San Francisco Bay Approach, California Current
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South Channel
Click for Map
Wed -- 01:19 AM PDT     0.89 knots Max Flood
Wed -- 04:43 AM PDT     -0.00 knots Slack
Wed -- 06:30 AM PDT     Sunrise
Wed -- 07:29 AM PDT     -1.11 knots Max Ebb
Wed -- 10:19 AM PDT     0.00 knots Slack
Wed -- 12:06 PM PDT     Moonset
Wed -- 01:33 PM PDT     0.96 knots Max Flood
Wed -- 04:59 PM PDT     -0.00 knots Slack
Wed -- 07:55 PM PDT     Sunset
Wed -- 07:59 PM PDT     -1.29 knots Max Ebb
Wed -- 11:22 PM PDT     Moonrise
Wed -- 11:23 PM PDT     0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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0.60.90.80.60.3-0.1-0.7-1.1-1-0.6-0.10.30.60.90.90.70.4-0-0.6-1.1-1.3-1.1-0.6-0.2

Weather Map and Satellite Images
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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.
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Wind Forecast for San Francisco/Monterey Bay Area, CA (3,6,7,8)
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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.