Wednesday, March29, 2017 L-36.com


Marine Weather and Tides
Half Moon Bay, CA

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:55AMSunset 7:31PM Wednesday March 29, 2017 8:08 AM PDT (15:08 UTC) Moonrise 7:16AMMoonset 8:36PM 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
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PZZ545 Point Reyes To Pigeon Point To 10 Nm- 307 Am Pdt Wed Mar 29 2017
.small craft advisory for rough bar in effect through this afternoon...
.small craft advisory in effect through Thursday afternoon...
Today..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. W swell 9 to 12 ft at 16 seconds.
Tonight..NW winds 15 to 25 kt. Wind waves 2 to 4 ft. W swell 8 to 10 ft at 15 seconds. Slight chance of showers after midnight.
Thu..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. W swell 8 to 10 ft at 14 seconds. Slight chance of showers in the morning.
Thu night..NW winds 20 to 30 kt. Wind waves 4 to 6 ft. W swell 9 to 12 ft at 14 seconds.
Fri..NW winds 15 to 25 kt. Wind waves 4 to 6 ft. W swell 9 to 12 ft at 12 seconds.
Sat..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. W swell 7 to 9 ft.
Sun..NW winds 25 to 35 kt. Combined seas 5 to 13 ft... Increasing to 6 to 18 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 8 to 10 ft with a dominant swell period of 16 seconds. Across the bar...combined seas 9 to 11 ft with a dominant swell period of 16 seconds. Maximum ebb current of 1.7 knots at 04:30 am Wednesday and 1.5 knots at 04:54 pm Wednesday.
PZZ500 307 Am Pdt Wed Mar 29 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Moderate and gusty northwest winds will persist over the central california coastal waters through the day with increasing winds possible over the bays by the evening hours. A weak frontal system will push through the area early Thursday, bringing with it the next chance of showers. High pressure will build later this week with increasing northwest winds approaching gale force by Thursday and Friday.

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 291151
afdmtr
area forecast discussion
national weather service san francisco bay area
451 am pdt Wed mar 29 2017

Synopsis A gradual warming trend will continue through
today as high pressure builds over the region. Cooler and breezy
conditions return on Thursday as a cold front sweeps through the
region. While a few light rain showers will be possible, most
locations will remain dry. The ridge will then rebuild back over
the region late in the week resulting in another warming trend
heading into the upcoming weekend.

Discussion As of 3:10 am pdt Wednesday... All signs point to
beautiful weather across our entire CWA today. Synoptically a
ridge of high pressure aloft will combine with warmer temperatures
at 925 mb and offshore flow at the surface to bring widespread
60s and 70s to the coast with 70s to lower 80s for inland
locations. Sunny conditions can also be expected along with
lighter winds than yesterday.

A system in the north pacific will dive to the southeast over the
next couple of days and move to eastern california/nevada on
Thursday. Showers associated with this feature will generally stay
to our east although a few sprinkles may occur especially over
the north and east bay hills. At the same time cooler air will
filter back in along with increasing gradients both at the surface
and aloft. Northwesterly winds will be on the increase through
the day with many spots forecast to see gusts over 25 mph. Coastal
locations should see the stronger winds with local gusts over 40
mph possible. Will allow the day crew to make the final call on
possible wind advisory. Temperatures will be considerably cooler
than today -- most spots will be 7 to 12 degrees lower.

The ridge of high pressure will quickly rebuild back into our
region starting on Friday and continue into the weekend. By
Saturday highs will be back to levels close to what we will see
today.

Another system will pass to our east by the end of the weekend
which will lead to temperatures being knocked down again going
into next work week. That will be followed by the ridge rebuilding
once again.

Finally, interesting to note that guidance continues to show a
return to wet weather starting around next Thursday as a system
moves in from the northwest that will have a moderate moisture tap
to use. Current ivt values favor around 250 kg/m/s although some
of the ensemble members have values over 500. Both the GFS and
ecmwf have widespread rainfall by next Friday. Still more than a
week down the road, however this potential change in the pattern
has been hinted at for quite a few days.

Aviation As of 4:50 am for the 12z tafs. High confidence that
vfr conditions will prevail for through at least 3z Thursday with
w to NW winds. Later in the forecast period, expecting low clouds
to develop and move onshore with drizzle or light rain between 8z
and 15z Thursday at san francisco bay area terminals. ExpectVFR
conditions to transition to MVFR and possible ifr ceilings as a
result. Confidence is low to medium after 3z Thursday.

Vicinity of ksfo...VFR on Wednesday, becoming MVFR/ifr after 8z
Thursday with light rain or drizzle developing. Westerly winds
with gusts approaching 20 to 25 kt on Wednesday afternoon.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR on Wednesday with W to NW winds,
becoming MVFR or possibly ifr with low ceilings after 6 to 9z
Thursday.

Marine As of 04:31 am pdt Wednesday... Moderate and gusty
northwest winds will persist over the central california coastal
waters through the day with increasing winds possible over the
bays by the evening hours. A weak frontal system will push
through the area early Thursday, bringing with it the next chance
of showers. High pressure will build later this week with
increasing northwest winds approaching gale force by Thursday and
Friday.

Mtr watches/warnings/advisories
Tday Sca... Pt arena to pt reyes 0-10 nm
sca... Pt reyes to pigeon pt 0-10 nm
sca... Pigeon pt to pt pinos 0-10 nm
sca... Pt pinos to pt piedras blancas 0-10 nm
sca... Pt arena to pigeon pt 10-60 nm until 3 pm
sca... Pigeon pt to pt piedras blancas 10-60 nm until 3 pm
sca... Rough bar advisory for sf bar
sca... Mry bay from 3 pm
sca... Sf bay from 3 pm
public forecast: bell
aviation: rowe
marine: rowe
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 14 mi56 min S 2.9 G 4.1 52°F 61°F1021.4 hPa
PXSC1 23 mi56 min 56°F 49°F
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 23 mi78 min NW 19 G 25 55°F 56°F12 ft1021.5 hPa (+0.0)
AAMC1 - 9414750 - Alameda, CA 23 mi56 min E 1.9 G 2.9 54°F 60°F1022.3 hPa
FTPC1 - 9414290 - San Francisco, CA 23 mi56 min S 2.9 G 2.9 53°F 56°F1022.2 hPa
46237 - San Francisco Bar, CA (142) 23 mi68 min 55°F10 ft
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi56 min E 1.9 G 4.1
OBXC1 24 mi56 min 56°F 50°F
LNDC1 25 mi56 min Calm G 1.9 55°F 1021.7 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 25 mi56 min ESE 1.9 G 2.9 55°F 1021.8 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi78 min NW 19 G 25 54°F 54°F10 ft1021.6 hPa (-0.3)
PPXC1 - 9414847 - Richmond (Point Potrero), CA 31 mi56 min E 1 G 1.9 56°F 1022.1 hPa
RCMC1 - 9414863 - Richmond, CA 32 mi56 min N 1.9 G 2.9 56°F 57°F1021.6 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 42 mi56 min SW 5.1 G 6 55°F 1021.5 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi56 min W 1.9 G 4.1 56°F 57°F1021.8 hPa47°F
UPBC1 44 mi56 min W 5.1 G 7
46042 - MONTEREY - 27NM West of Monterey Bay, CA 47 mi78 min 21 G 27 56°F 56°F12 ft1021.1 hPa (-0.4)
PCOC1 - 9415144 - Port Chicago, CA 47 mi50 min SW 6 G 7 51°F 57°F1021.3 hPa

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA3 mi13 minN 64.00 miFair with Haze54°F46°F77%1022.3 hPa
San Francisco, San Francisco International Airport, CA12 mi12 minWNW 710.00 miA Few Clouds55°F46°F74%1022 hPa
San Carlos Airport, CA13 mi11 minN 010.00 miA Few Clouds54°F44°F72%1022.3 hPa
Palo Alto Airport, CA19 mi21 minN 010.00 miA Few Clouds52°F48°F88%1022 hPa
Oakland, Metro Oakland International Airport, CA21 mi15 minN 010.00 miA Few Clouds54°F50°F87%1022.2 hPa
Mountain View, Moffett Field, CA23 mi72 minN 010.00 miFair51°F46°F86%1022.3 hPa
Hayward, Hayward Air Terminal, CA23 mi14 minENE 310.00 miFair54°F44°F69%1023.1 hPa

Wind History from SFO (wind in knots)
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Last 24hrW7NW104W16W17W19
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1 day agoNW10NW13NW14
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2 days agoS3SE5E7E11E9S6S12S11S12S15S14S8W10W16W14W9W12W13W8NW4NW7NW7W10W12

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
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Wed -- 06:12 AM PDT     0.01 feet Low Tide
Wed -- 06:59 AM PDT     Sunrise
Wed -- 08:15 AM PDT     Moonrise
Wed -- 12:34 PM PDT     5.12 feet High Tide
Wed -- 06:22 PM PDT     0.82 feet Low Tide
Wed -- 07:30 PM PDT     Sunset
Wed -- 09:36 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
5.75.34.331.50.500.212.13.34.455.14.53.52.41.40.911.72.73.95

Tide / Current Tables for San Mateo Bridge, South San Francisco Bay, California Current
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San Mateo Bridge
Click for Map
Wed -- 02:49 AM PDT     -0.00 knots Slack
Wed -- 06:08 AM PDT     -1.93 knots Max Ebb
Wed -- 06:58 AM PDT     Sunrise
Wed -- 08:14 AM PDT     Moonrise
Wed -- 09:10 AM PDT     0.01 knots Slack
Wed -- 11:59 AM PDT     2.03 knots Max Flood
Wed -- 03:30 PM PDT     -0.00 knots Slack
Wed -- 06:33 PM PDT     -1.63 knots Max Ebb
Wed -- 07:29 PM PDT     Sunset
Wed -- 09:24 PM PDT     0.00 knots Slack
Wed -- 09:35 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.91.50.8-0.1-0.9-1.6-1.9-1.7-1-0.20.91.721.81.30.5-0.4-1.1-1.6-1.6-1-0.30.51.4

Weather Map and Satellite Images
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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 (11,2,3,4)
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Ground Weather Radar Station San Francisco Bay Area, CA
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weather_mapweather_map weather_map

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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.