Thursday, June22, 2017 L-36.com


Marine Weather and Tides
Half Moon Bay, CA

Version 3.4
What's New / NOTES
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
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.

Sunrise 5:47AMSunset 8:36PM Thursday June 22, 2017 7:06 AM PDT (14:06 UTC) Moonrise 3:43AMMoonset 6:08PM Illumination 3% Phase: Waning Crescent; Moon at 28 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- 305 Am Pdt Thu Jun 22 2017
Today..S winds 10 kt. Wind waves 2 ft or less. NW swell 5 to 7 ft at 11 seconds and S 3 ft at 15 seconds. Patchy dense fog in the morning.
Tonight..S winds 5 to 15 kt. Wind waves 1 to 3 ft. Mixed swell nw 4 to 6 ft at 11 seconds and S 3 ft at 14 seconds. Patchy fog after midnight.
Fri..S winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 4 to 6 ft at 10 seconds. Patchy fog in the morning.
Fri night..SW winds 10 kt. Wind waves 2 ft or less. NW swell 3 to 5 ft at 10 seconds. Patchy fog after midnight.
Sat..W winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft at 10 seconds. SWell sw 3 ft. Patchy fog in the morning.
Sun..W winds 5 to 15 kt. Wind waves 1 to 3 ft...becoming 2 ft or less. NW swell 3 ft. SWell sw 3 ft.
Mon..NW winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 4 to 6 ft with a dominant swell period of 10 seconds. Across the bar...combined seas 5 to 7 ft with a dominant swell period of 10 seconds. Maximum ebb current of 1 knots at 02:48 pm Thursday and 2.2 knots at 02:42 am Friday.
PZZ500 305 Am Pdt Thu Jun 22 2017
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Split flow with moderate northwest winds primarily over the northern outer waters with lighter southwest winds elsewhere. Hazardous seas from steep wind waves and fresh swell can be expected over the outer waters through the day. Look for gradually improving conditions late today through the remainder of the week.

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 221152
afdmtr
area forecast discussion
national weather service san francisco bay area
452 am pdt Thu jun 22 2017

Hot weather continues inland through this evening...

Synopsis Heat advisories and warnings are in place today
through 9 pm for dangerously hot temperatures. A shallow marine
layer along the central coast will keep the monterey bay coastal
areas much cooler. All areas start to gradually cool Friday and
through the weekend as more persistent onshore flow returns to the
region.

Discussion As of 4:06 am pdt Thursday... Northerly gradient
down the coast is still around 6 mb and helping to support some
north northeast winds across the north bay hills. A few sites in
the north bay hills are still above 90 as of 3 am with widespread
70s and 80s in the hills. There is still enough onshore flow at
the surface with 2 mb sfo to sac to allow the valleys to cool into
the 60s. Its this somewhat subtle northerly wind flow in the
hills that will set the stage for rapid warming today, especially
for the interior of the north and east bay. Essentially heat
advisories are in place near sf bay and some of the valleys with
warnings in place for the hills and far east bay where warm
overnight lows and hot days have meant little or no relief from
the heat. The warnings advisories remain in place through 9 pm. If
seeking relief the coast from santa cruz southward through
monterey county is the place to be with an 800 foot marine layer
in place. The immediate coast will remain out of any headlines.

Even though 850 mb temps dont change too much into Friday we
expect noted cooling to occur especially for the coastal and
bayside valleys. The upper flow will become so amplified and
eventually buckle with weak surface low pressure (around 1010 mb)
developing well offshore. This in combination with the excessive
heat across the central valley will induce persistent onshore flow
Friday and through the weekend as well as a deepening marine
layer. Upshot is to expect a modest cooling trend back to more
seasonable levels.

Long range trends on the latest ECMWF show the upper pattern with
a trough off the coast suggesting near to perhaps slightly below
normal temperatures for next week. No precipitation, outside of
coastal drizzle is forecast.

Aviation As of 4:50 pm pdt Thursday... The marine stratus deck
is struggling under the dry, subsiding high pressure dome set up
over the area. As a result, widespreadVFR conditions are being
reported at TAF sites. That said, marine stratus is still
obscuring the monterey bay and portion of the northern salinas
valley. For today, generally light occasionally breezy winds and
clear skies will prevail. For tonight, mostly clear skies with
some stratus primarily banked up along the monterey expected.

Vicinity of ksfo...VFR. Light winds becoming breezy by the
afternoon up to 15 kt.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR at the TAF sites with lifr to ifr
cigs due to marine stratus in the vicinity of the TAF sites. Light
winds. Low clouds will briefly return tonight but depart before
sunrise.

Fire weather As of 4:06 am pdt Thursday... The most critical
areas this morning will be the hills of the north bay, especially
napa county and around mt st helena where winds above 2000 feet
will be northeast and gusting 20-25 mph. Humidity values are
starting to drop down to 20-30% in the hills as of 3 am with hot
temperatures in the 80s and lower 90s at this early hour. Expect a
hot and dry day all inland areas and hills today. Main concern
this afternoon will be a transition to westerly winds should any
new starts occur.

Although onshore flow will return by tonight, the marine layer
will remain shallow and the airmass aloft will remain very warm
for a few more days. Thus, conditions in the hills will only
gradually improve from Friday through the weekend. Much improved
conditions are expected by early next week.

Climate
Here is a list of record high temperatures
sf bay area Thursday
location... ... ... ... ... ..Temp year
kentfield... ... ... ... ... .102 1989
san rafael... ... ... ... ... .99 2006
napa... ... ... ... ... ... ... 105 1981
san francisco... ... ... ... .97 1989
sfo airport... ... ... ... ... 98 1989
oakland airport... ... ... ..94 1957
richmond... ... ... ... ... ... 94 1989
livermore... ... ... ... ... .110 1961
moffett field... ... ... ... .99 1989
san jose... ... ... ... ... ..101 1989
gilroy... ... ... ... ... ... .110 1973
monterey bay area Thursday
location... ... ... ... .. Temp year
salinas... ... ... ... ... ... .89 1981
salinas airport... ... ... ..92 1947
king city... ... ... ... ... .110 1929

Marine As of 04:46 am pdt Thursday... Split flow with moderate
northwest winds primarily over the northern outer waters with
lighter southwest winds elsewhere. Hazardous seas from steep wind
waves and fresh swell can be expected over the outer waters
through the day. Look for gradually improving conditions late
today through the remainder of the week.

Mtr watches warnings advisories
Tday Heat advisory... Caz508 11 am til 9 pm
heat advisory... Caz506-513-516-518 til 9 pm
excessive heat warning... Caz507-510>512-517 til 9 pm
sca... Pt arena to pigeon pt 10-60 nm
sca... Pt arena to pt reyes 0-10 nm until 9 am
sca... Pigeon pt to pt piedras blancas 10-60 nm until 3 pm
public forecast: rww
aviation: drp
marine: drp
fire weather: rww
visit us at

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 14 mi55 min NNE 2.9 G 4.1 64°F 74°F1004.8 hPa
FTPC1 - 9414290 - San Francisco, CA 23 mi55 min W 8 G 13 57°F 59°F1005.9 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 23 mi77 min SSE 5.8 G 9.7 55°F 55°F9 ft1005.1 hPa (+0.0)
PXOC1 - 9414311 - San Francisco (Pier 1), CA 23 mi55 min W 1.9 G 4.1 60°F 1004.5 hPa
AAMC1 - 9414750 - Alameda, CA 23 mi55 min NNW 5.1 G 6 62°F 67°F1005.9 hPa
PXSC1 23 mi55 min 60°F 55°F
46237 - San Francisco Bar, CA (142) 23 mi67 min 55°F6 ft
OBXC1 24 mi55 min 61°F 56°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi61 min NNW 2.9 G 2.9
OKXC1 - 9414776 - Oakland (Berth 34), CA 25 mi55 min WNW 7 G 8 60°F 1005.5 hPa
LNDC1 25 mi55 min N 4.1 G 6 61°F 1005.3 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi77 min ESE 5.8 G 7.8 55°F 54°F6 ft1005.7 hPa (+0.5)
TIBC1 - Tiburon Pier, San Francisco Bay, CA 29 mi60 min Calm 62°F 1006 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 31 mi55 min Calm G 1 63°F 1005.7 hPa
RCMC1 - 9414863 - Richmond, CA 32 mi55 min Calm G 1.9 62°F 60°F1005.3 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 42 mi55 min WSW 5.1 G 6 65°F 1005.1 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi55 min WNW 12 G 16 67°F 69°F1005.1 hPa60°F
UPBC1 44 mi61 min WNW 14 G 18
PRYC1 - 9415020 - Point Reyes, CA 45 mi55 min SE 9.9 G 13 59°F 54°F1005.4 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 47 mi77 min 54°F 55°F9 ft1006.1 hPa (+0.0)
PCOC1 - 9415144 - Port Chicago, CA 47 mi55 min SW 8 G 9.9 67°F 70°F1004.6 hPa

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Francisco, San Francisco International Airport, CA12 mi71 minNW 56.00 miFair with Haze60°F53°F78%1005.1 hPa
San Carlos Airport, CA13 mi72 minN 05.00 miMostly Cloudy with Haze64°F57°F78%1005.4 hPa
Oakland, Metro Oakland International Airport, CA21 mi74 minNNW 35.00 miFair with Haze63°F55°F78%1005.2 hPa
Mountain View, Moffett Field, CA23 mi71 minW 39.00 miFair68°F59°F73%1005.7 hPa
Hayward, Hayward Air Terminal, CA23 mi73 minN 07.00 miFair66°F53°F63%1006 hPa

Wind History from SFO (wind in knots)
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Last 24hrNW4NW5N4NE7NE6NE6N7NW15NW16NW16NW18NW14NW14W14W10W8W10W10W7NW6W5W5W9NW5
1 day agoNW8W63N6NW11NW14NW13NW20W20W20W25W18W21
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2 days agoW6N3NE4N6N6NW10NW15NW12NW16NW19W22W20
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Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
Click for Map
Thu -- 03:54 AM PDT     -1.07 feet Low Tide
Thu -- 04:43 AM PDT     Moonrise
Thu -- 05:49 AM PDT     Sunrise
Thu -- 10:41 AM PDT     4.38 feet High Tide
Thu -- 03:33 PM PDT     2.05 feet Low Tide
Thu -- 07:08 PM PDT     Moonset
Thu -- 08:34 PM PDT     Sunset
Thu -- 09:39 PM PDT     6.61 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
3.41.60.1-0.8-1.1-0.70.21.32.53.54.24.443.32.62.12.12.73.64.75.86.56.66

Tide / Current Tables for San Mateo Bridge, South San Francisco Bay, California Current
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San Mateo Bridge
Click for Map
Thu -- 03:30 AM PDT     -2.21 knots Max Ebb
Thu -- 04:41 AM PDT     Moonrise
Thu -- 05:48 AM PDT     Sunrise
Thu -- 06:56 AM PDT     0.01 knots Slack
Thu -- 09:48 AM PDT     2.18 knots Max Flood
Thu -- 01:25 PM PDT     -0.00 knots Slack
Thu -- 04:04 PM PDT     -1.18 knots Max Ebb
Thu -- 06:46 PM PDT     0.00 knots Slack
Thu -- 07:07 PM PDT     Moonset
Thu -- 08:33 PM PDT     Sunset
Thu -- 09:31 PM PDT     1.75 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.1-0.9-1.7-2.2-2.1-1.7-0.90.11.222.21.91.30.4-0.4-1-1.2-1-0.50.21.11.71.71.3

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 (10,2,3,4)
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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.