Tuesday, October15, 2019 L-36.com


Marine Weather and Tides
Half Moon Bay, CA

Version 3.4
NOTICE
10/9/2019 Updated the Marine Zones.
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 7:16AMSunset 6:34PM Tuesday October 15, 2019 3:56 AM PDT (10:56 UTC) Moonrise 6:57PMMoonset 7:53AM Illumination 97% Phase: Waning Gibbous; Moon at 16 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- 220 Am Pdt Tue Oct 15 2019
Today..NW winds 5 to 10 kt. Wind waves 1 ft, increasing to 2 to 3 ft this afternoon. NW swell 3 to 4 ft at 11 seconds and sw around 2 ft at 18 seconds.
Tonight..NW winds 5 to 15 kt. Wind waves 3 to 4 ft. NW swell around 3 ft at 10 seconds and sw around 2 ft at 18 seconds.
Wed..NW winds 5 to 10 kt. Wind waves 3 to 4 ft. NW swell 3 to 4 ft at 12 seconds and W around 2 ft at 20 seconds.
Wed night..SW winds up to 10 kt. Wind waves 1 to 2 ft. W swell 4 to 6 ft at 18 seconds and W 3 to 4 ft at 11 seconds. A slight chance of rain.
Thu..NW winds 10 to 20 kt with gusts up to 25 kt. Wind waves 5 to 6 ft. W swell 7 to 9 ft at 15 seconds and nw around 3 ft at 10 seconds.
Thu night..NW winds 15 to 20 kt with gusts up to 30 kt. Wind waves 5 to 6 ft. W swell 10 to 12 ft at 16 seconds and sw around 2 ft at 15 seconds.
Fri..NW winds 5 to 15 kt. Wind waves 4 to 5 ft. W swell 8 to 10 ft and sw around 2 ft.
Sat..NW winds 10 to 20 kt. Wind waves 4 to 5 ft. W swell 6 to 8 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...seas 3 to 5 ft with a dominant period of 12 seconds. Across the bar...seas 4 to 7 ft with a dominant period of 12 seconds. Maximum ebb current of 1.7 kt at 06:13 am Tuesday and 3.5 kt at 05:55 pm Tuesday.
PZZ500 220 Am Pdt Tue Oct 15 2019
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Generally light northwest winds are forecast to prevail over the coastal waters through Tuesday. Winds will gradually increase later this week behind a passing front that will bring a slight chance of light rain to parts of the waters. A larger northwest swell is forecast to arrive later this week with forerunners expected as early as Wednesday night or Thursday.


7 Day Forecast for Marine Location Near Half Moon Bay, CA
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location: 37.47, -122.48     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 151005
afdmtr
area forecast discussion
national weather service san francisco bay area
305 am pdt Tue oct 15 2019

Synopsis Slight warming will be possible across the interior
today ahead of a weak frontal system that will move through the
region Wednesday night. Light rain will be possible for portions of
the north bay and as far south as the monterey peninsula late
Wednesday into early Thursday. Breezy conditions develop and
temperatures turn cooler for the remainder of the week in wake of
the frontal passage.

Discussion As of 03:04 am pdt Tuesday... A marine layer of
between 1,000 to 1,500 feet in depth has resulted in stratus
development along the coast and locally inland into the salinas
valley. Meanwhile, patchy dense fog is being reported in the
sonoma valley and portions of northern marin county. Temperatures
region-wide range from the middle 40s in the cooler valley
locations to the lower 50s. A slight warming trend will be
possible across interior portions of the region this afternoon as
a weak short-wave ridge builds over the region. However, many
coastal locations will see little change overall compared to
yesterday given the persistent onshore flow and overnight morning
cloud cover.

Conditions will not change much overnight in advance of an
approaching weather system that will push into the pacific northwest
late tonight into Wednesday. This system will push a frontal
boundary through the san francisco bay area by Wednesday night
resulting in a slight chance of light rain across portions of the
north bay. Precipitation along this boundary is forecast to be light
in nature as the frontal boundary dissipates over the central coast
early Thursday morning. The latest operational models and ensemble
members show light rain as far south as monterey, yet widespread
measurable rainfall south of the north bay (primarily sonoma county)
appears unlikely. Those that do pick up measurable rainfall will
likely see less than a tenth of an inch.

Increasing northwest winds are forecast to develop and become gusty
by Thursday afternoon in wake of the frontal passage. At this time,
cannot rule out gsts of 30 to 40 mph along coastal areas and in the
higher elevations. A much cooler air mass will also advect into the
region with daytime high temperatures likely to remain the 60s to
lower 70s. Some coastal and higher elevation locations may even
struggle to warm out of the upper 50s Thursday afternoon. Little
change is forecast heading into Friday as well as Saturday with
seasonably cool and breezy weather conditions. Another weak short-
wave trough is forecast to bring another round of light
precipitation to northern california and as far south as sonoma
county Friday night into Saturday. However, as with the first
system, precipitation if any will be very light. A more robust
warming and drying trend is then likely Sunday into early next week
as a ridge of high pressure builds over the region.

Aviation As of 10:34 pm pdt Monday... Satellite imagery shows
more widespread stratus along the coast than yesterday. An upper
level ridge is moving over the area and a marine layer has
developed and is deepening. This has brought stratus into the mry
bay area early tonight although it has temporarily retreated due
to an eddy circulation over mry bay. More stratus will move into
the east bay tonight and could spread into sfo and sjc late
tonight. Fog likely once again in the north bay valleys and ksts.

Vicinity of ksfo... Possible brief ifr CIGS between 12z and 16z
with bases around 900 feet.

Sfo bridge approach... Same as ksfo.

Monterey bay terminals... Stratus was in over mry and sns but has
retreated to the bay. With the marine layer deepening the ifr cigs
should return after 09z.

Marine As of 03:04 am pdt Tuesday... Generally light northwest
winds are forecast to prevail over the coastal waters through
Tuesday. Winds will gradually increase later this week behind a
passing front that will bring a slight chance of light rain to
parts of the waters. A larger northwest swell is forecast to
arrive later this week with forerunners expected as early as
Wednesday night or Thursday.

Mtr watches warnings advisories
Tday None.

Public forecast: rgass
aviation: W pi
marine: rowe
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Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 14 mi56 min SSW 1 G 2.9 53°F 67°F1017.9 hPa (+0.0)
PXOC1 - 9414311 - San Francisco (Pier 1), CA 23 mi56 min W 6 G 8.9 51°F 1016.5 hPa
46237 - San Francisco Bar, CA (142) 23 mi86 min 55°F4 ft
AAMC1 - 9414750 - Alameda, CA 23 mi56 min WNW 2.9 G 4.1 53°F 63°F1017.9 hPa (+0.3)
FTPC1 - 9414290 - San Francisco, CA 23 mi56 min W 2.9 G 8 51°F 57°F1017.9 hPa (+0.4)
PXSC1 23 mi56 min 52°F 52°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi56 min W 2.9 G 6
OBXC1 24 mi56 min 53°F 52°F
LNDC1 25 mi56 min N 2.9 G 4.1 53°F 1017.4 hPa (+0.3)
OKXC1 - 9414776 - Oakland (Berth 34), CA 25 mi56 min WNW 6 G 8 53°F 1017.4 hPa (+0.3)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi36 min NW 1.9 G 7.8 51°F 56°F1018.4 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 29 mi45 min Calm 50°F 1017 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 31 mi56 min SSW 9.9 G 12 53°F 1017.6 hPa
RCMC1 - 9414863 - Richmond, CA 32 mi56 min WNW 1 G 2.9 53°F 60°F1017.4 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 42 mi56 min WSW 7 G 9.9 54°F 1017 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi56 min WNW 9.9 G 13 53°F 64°F1016.9 hPa (+0.0)53°F
UPBC1 44 mi56 min WNW 8.9 G 13
PRYC1 - 9415020 - Point Reyes, CA 45 mi56 min 56°F1017.8 hPa (+0.6)
PCOC1 - 9415144 - Port Chicago, CA 47 mi56 min WSW 8.9 G 9.9 52°F 64°F1016.9 hPa (+0.4)
46042 - MONTEREY - 27NM West of Monterey Bay, CA 48 mi66 min 7.8 G 9.7 53°F 58°F8 ft1017.1 hPa (+0.4)

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA3 mi61 minNE 47.00 miOvercast50°F48°F94%1018.3 hPa
San Francisco, San Francisco International Airport, CA12 mi2 hrsWNW 610.00 miA Few Clouds50°F46°F89%1017.2 hPa
Oakland, Metro Oakland International Airport, CA21 mi63 minN 010.00 miA Few Clouds49°F46°F93%1017.6 hPa
Hayward, Hayward Air Terminal, CA23 mi62 minNE 310.00 miFair50°F44°F80%1018.2 hPa

Link to 5 minute data for KSFO

Wind History from SFO (wind in knots)
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Last 24hr3W6W7SW3SW4CalmCalmNE5NE5NE4NW11W14W17W16W13W12W14W13W10W9W9NW4W6W11
1 day agoW10W5W5CalmW12W10NW4NE3NW13NW9NW10W15W16W17W14W9NW10NW7NW7W10W6W6CalmCalm
2 days agoCalmSW4CalmCalmCalmN4N5N5NE4NE4N4NE3NW12NW11NW12W14W14W14W8S4W6W7W7W3

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
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Tue -- 12:11 AM PDT     4.59 feet High Tide
Tue -- 05:46 AM PDT     1.80 feet Low Tide
Tue -- 07:18 AM PDT     Sunrise
Tue -- 08:52 AM PDT     Moonset
Tue -- 11:50 AM PDT     5.36 feet High Tide
Tue -- 06:23 PM PDT     0.38 feet Low Tide
Tue -- 06:32 PM PDT     Sunset
Tue -- 07:57 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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4.64.53.93.22.41.91.82.22.93.74.65.25.454.231.80.90.40.511.82.83.6

Tide / Current Tables for San Mateo Bridge, South San Francisco Bay, California Current
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San Mateo Bridge
Click for Map
Tue -- 03:14 AM PDT     -0.00 knots Slack
Tue -- 06:07 AM PDT     -1.22 knots Max Ebb
Tue -- 07:17 AM PDT     Sunrise
Tue -- 08:52 AM PDT     Moonset
Tue -- 09:00 AM PDT     0.00 knots Slack
Tue -- 11:41 AM PDT     1.38 knots Max Flood
Tue -- 02:53 PM PDT     -0.00 knots Slack
Tue -- 06:21 PM PDT     -1.68 knots Max Ebb
Tue -- 06:31 PM PDT     Sunset
Tue -- 07:56 PM PDT     Moonrise
Tue -- 09:34 PM PDT     0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.61.40.90.2-0.5-1-1.2-1-0.6-00.71.21.41.10.6-0.1-0.7-1.3-1.7-1.6-1-0.40.41.2

Weather Map
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wmap_P
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 (6,6,7,8)
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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.