Friday, March22, 2019 L-36.com


Marine Weather and Tides
Half Moon Bay, CA

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 7:09AMSunset 7:23PM Thursday March 21, 2019 10:52 PM PDT (05:52 UTC) Moonrise 7:26PMMoonset 6:56AM Illumination 98% 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- 848 Pm Pdt Thu Mar 21 2019
.small craft advisory in effect from 3 am pdt Friday through late Friday night...
Tonight..W winds 5 to 10 kt...becoming S after midnight. Wind waves 2 ft or less. W swell 2 to 4 ft at 19 seconds and W 4 to 6 ft at 12 seconds. A slight chance of rain after midnight.
Fri..S winds 15 to 25 kt with gusts up to 30 kt. Wind waves 3 to 4 ft. W swell 4 to 7 ft at 18 seconds and W 2 to 3 ft at 11 seconds. Rain.
Fri night..W winds 10 to 20 kt with gusts up to 30 kt. Wind waves 3 to 4 ft. W swell 7 to 10 ft at 17 seconds and S 1 to 2 ft at 14 seconds. A chance of showers.
Sat..NW winds 10 to 15 kt. Wind waves 2 ft or less. W swell 9 to 12 ft at 16 seconds and S 1 to 2 ft at 13 seconds.
Sat night..NW winds 5 to 15 kt. Wind waves 2 ft or less. W swell 9 to 12 ft at 16 seconds and S 1 to 2 ft at 13 seconds.
Sun..SE winds 5 to 15 kt. Wind waves 2 ft or less. W swell 7 to 10 ft at 15 seconds and S 1 to 2 ft at 18 seconds.
Sun night..S winds 10 to 15 kt. Wind waves 2 ft or less. W swell 5 to 8 ft at 14 seconds and S 1 to 2 ft at 18 seconds. A chance of showers.
Mon..S winds 5 to 15 kt. Wind waves 2 ft or less. W swell 6 to 8 ft and sw 1 to 2 ft. Showers likely.
Tue..S winds 5 to 15 kt. Wind waves 2 ft or less. W swell 6 to 9 ft and sw 1 to 2 ft. Showers likely.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 6 to 8 ft with a dominant of 12 seconds. Across the bar...combined seas 7 to 9 ft with a dominant period of 12 seconds. Maximum ebb current of 3.6 kt at 06:07 am Friday and 2.8 kt at 06:43 pm Friday.
PZZ500 848 Pm Pdt Thu Mar 21 2019
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Winds will turn southerly and increase later tonight and Friday as a frontal system moves across the coastal waters. Winds will switch to northwest Friday night ater the front passes. A moderate long-period swell will arrive Friday and continue through Saturday.


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 220347
afdmtr
area forecast discussion
national weather service san francisco bay area
847 pm pdt Thu mar 21 2019

Synopsis Dry conditions are expected tonight ahead of the next
frontal system that will bring widespread rainfall to the region
on Friday and Friday night. Mainly dry conditions are expected
over the upcoming weekend, with unsettled weather then likely
throughout at least the first half of next week.

Discussion As of 8:45 pm pdt Thursday... Dry conditions
prevailed across our region today, except for an isolated shower
that developed over the santa cruz mountains late this afternoon.

Afternoon highs were mostly in the lower to mid 60s.

Evening satellite imagery shows a relatively robust frontal
system approaching the northern california coast. The moisture
plume along the frontal boundary is respectable with precipitable
water values as high as 1.2 inches. Models agree quite well on
rainfall timing: light warm advection precipitation is forecast
to begin spreading onto the north bay coast just prior to sunrise
Friday, with light rain then developing across the entire north
bay during the morning hours, and as far south as san mateo and
alameda counties by midday. For tomorrow morning's commute, wet
roadways are most likely in the north bay, while locations south
of the golden gate will probably remain dry through the bulk of
the morning commute.

Rain rates are expected to increase in the north bay during the
early afternoon hours as the cold frontal rain band pushes
onshore. Moderate to brief heavy rain rates with the cold front
are then expected to push south and east through the remainder of
the sf bay area during the late afternoon and early evening hours,
and finally south through most of the rest of our forecast area
during the late evening hours and overnight Friday night.

Latest hrrr model rainfall totals through late Friday night range
from a half inch to an inch in most locations, except a quarter
inch or less across the far southern portion of our area where the
front is forecast to wash out late Friday night. Up to 1.5 inches
are expected in the north bay mountains, santa cruz mountains, and
locally in the santa lucia mountains. The hrrr's rainfall forecast
with this system is consistent with other model output.

Winds are not expected to be a significant factor with this
incoming system. The local WRF model forecasts locally gusty winds
along the coast from san mateo county northward, as well as
locally in the hills, on Friday and Friday evening. But wind gusts
in these areas are forecast to be no more than about 30 mph.

The models agree that there won't be much in the way of post-
frontal shower activity with this system. So, after a few
lingering showers on Saturday morning, mainly across the southern
portion of our area, we can expect dry conditions for the
remainder of the upcoming weekend. Weekend high temperatures are
forecast to be about five degrees cooler than seasonal averages on
Saturday, but then warm a few degrees on Sunday.

After a brief dry break over the weekend, the models agree that
an active weather pattern will return by early next week, with a
system forecast to spread rain across much of our area from Sunday
night into Monday and another set to bring more rain from late
Tuesday into Wednesday. Details regarding timing and exact
location of heaviest rainfall with these systems next week remains
rather hard to pin down given model differences. One item of
note... Yesterday's ECMWF indicated the potential for prolonged
rainfall in the north bay from Sunday night through late Tuesday,
with very little break between the two systems, but today's ecmwf
forecasts about a 24 hour dry break in between.

Aviation As of 11:00 am pdt Thursday... A few cumulus clouds
over the higher terrain are not impacting the approach or the
terminals today.VFR expected tonight as mid and high clouds
increase and gradually lower ahead of the next frontal system.

Initially a warm front will bring CIGS down to MVFR in the bay
area with an initial round of light rain Friday morning. There
may be a short break in the rain between the warm front passage
and the arrival of the cold front but CIGS likely remaining MVFR.

Vsbys will lower and light to moderate rain will return in the
afternoon.

Onshore winds will diminish tonight then switch to southeast on
Friday. Winds should really pick up in the afternoon in the bay
area with gusts to around 25 kt.

Vicinity of ksfo...VFR through tonight. Mid and high clouds will
move in tonight with CIGS gradually lowering overnight. MVFR cigs
after 15z continuing through the day. Light rain could begin as
early as 10-12z as the warm front moves through. There may be a
short break in the rain late in the morning but rain will return
after 21z along with reduced vsbys to 3-5 miles. Onshore winds
to 15 kt diminishing overnight then becoming light southeast
Friday morning. Wind speeds increasing after 21z with gusts to
25 kt.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR tonight. Increasing clouds Friday
morning with CIGS remaining in theVFR category. Rain and lower
cigs late in the afternoon. Winds becoming southeast overnight
with stronger gusts through the salinas valley. Gusts to 15 kt at
sns Friday morning increasing to 25 kt after after around 16z.

Marine As of 04:29 pm pdt Thursday... Weak transitory ridge over
the area through the remainder of the day will result in light to
locally breezy west to northwest winds. Winds turn southerly and
increase by sunrise Friday as a frontal system moves in. A
moderate west swell will dissipate through the next 24 hours but a
different, longer period west swell has already begun to build
into the waters this afternoon.

Mtr watches warnings advisories
Tngt Sca... Pt arena to pigeon pt 10-60 nm from 9 pm
sca... Pt arena to pt reyes 0-10 nm from 3 am
sca... Pt reyes to pigeon pt 0-10 nm from 3 am
public forecast: dykema
aviation: W pi
marine: drp
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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 mi53 min SW 2.9 G 4.1 53°F 62°F1021.8 hPa (+1.0)
PXOC1 - 9414311 - San Francisco (Pier 1), CA 23 mi53 min W 6 G 8 54°F 1020.2 hPa (+1.0)
46237 - San Francisco Bar, CA (142) 23 mi53 min 55°F7 ft
AAMC1 - 9414750 - Alameda, CA 23 mi53 min WSW 5.1 G 7
FTPC1 - 9414290 - San Francisco, CA 23 mi53 min WSW 8 G 12
PXSC1 23 mi53 min 55°F 50°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi53 min WSW 8 G 8.9
OBXC1 24 mi53 min 55°F 50°F
LNDC1 25 mi53 min WSW 7 G 8 55°F 1021.2 hPa (+1.1)
OKXC1 - 9414776 - Oakland (Berth 34), CA 25 mi53 min W 4.1 G 6 54°F 1021.3 hPa (+1.3)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi33 min SW 5.8 G 7.8 54°F 55°F1021.7 hPa
TIBC1 - Tiburon Pier, San Francisco Bay, CA 29 mi54 min SW 1.9 52°F 1021 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 31 mi53 min SW 7 G 8.9 55°F 1021.3 hPa (+1.1)
RCMC1 - 9414863 - Richmond, CA 32 mi53 min W 5.1 G 6
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 42 mi53 min WNW 9.9 G 11 55°F 1020.7 hPa (+1.1)
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi53 min WSW 8 G 8.9 53°F 56°F1020.8 hPa (+1.1)51°F
UPBC1 44 mi53 min W 8.9 G 11
PRYC1 - 9415020 - Point Reyes, CA 45 mi53 min 56°F1020.9 hPa (+0.7)
PCOC1 - 9415144 - Port Chicago, CA 47 mi53 min SW 8.9 G 9.9 51°F 57°F1020.8 hPa (+1.0)
46042 - MONTEREY - 27NM West of Monterey Bay, CA 48 mi63 min WNW 5.8 G 7.8 55°F 56°F7 ft1021.2 hPa (+0.8)

Wind History for Redwood City, CA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA3 mi58 minN 08.00 miOvercast46°F44°F93%1021.7 hPa
San Francisco, San Francisco International Airport, CA12 mi2.9 hrsWSW 1010.00 miA Few Clouds53°F45°F74%1020.3 hPa
San Carlos Airport, CA13 mi58 minWNW 410.00 miFair54°F46°F77%1021.3 hPa
Palo Alto Airport, CA19 mi2.1 hrsW 410.00 miA Few Clouds54°F42°F67%1021 hPa
Oakland, Metro Oakland International Airport, CA21 mi60 minW 1010.00 miA Few Clouds55°F48°F77%1021.2 hPa
Hayward, Hayward Air Terminal, CA23 mi59 minWNW 410.00 miFair58°F45°F62%1022.1 hPa
Mountain View, Moffett Field, CA23 mi2.9 hrsWNW 410.00 miFair57°F43°F60%1020.9 hPa

Wind History from HAF (wind in knots)
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Last 24hrE4CalmNE3NE4CalmCalmCalmNE3CalmCalmCalmN4NW9W9W9NW10NW9NW10NW10NW6NW6CalmCalmCalm
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W8SW7SW8SW7W6W5SW6CalmNE4CalmNE3
2 days agoS8SE7NE3N3CalmNE4CalmCalmCalmCalmCalmCalmCalmS8SW7S4SE6SE6SW5S8
G15
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G18

Tide / Current Tables for Half Moon Bay, California
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Half Moon Bay
Click for Map
Fri -- 12:12 AM PDT     5.77 feet High Tide
Fri -- 06:17 AM PDT     0.23 feet Low Tide
Fri -- 07:10 AM PDT     Sunrise
Fri -- 08:30 AM PDT     Moonset
Fri -- 12:28 PM PDT     5.45 feet High Tide
Fri -- 06:30 PM PDT     0.47 feet Low Tide
Fri -- 07:23 PM PDT     Sunset
Fri -- 09:35 PM PDT     Moonrise
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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5.75.54.73.31.90.80.30.41.22.43.64.75.45.44.73.62.31.20.50.61.22.33.54.7

Tide / Current Tables for San Mateo Bridge, South San Francisco Bay, California Current
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San Mateo Bridge
Click for Map
Fri -- 02:59 AM PDT     -0.00 knots Slack
Fri -- 06:09 AM PDT     -1.87 knots Max Ebb
Fri -- 07:09 AM PDT     Sunrise
Fri -- 08:29 AM PDT     Moonset
Fri -- 09:14 AM PDT     0.01 knots Slack
Fri -- 12:00 PM PDT     2.09 knots Max Flood
Fri -- 03:27 PM PDT     -0.01 knots Slack
Fri -- 06:32 PM PDT     -1.72 knots Max Ebb
Fri -- 07:22 PM PDT     Sunset
Fri -- 09:34 PM PDT     Moonrise
Fri -- 09:35 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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2.11.71-0-0.9-1.6-1.9-1.7-1.1-0.20.91.82.11.91.30.5-0.5-1.2-1.7-1.7-1.2-0.50.41.4

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 (1,6,7,8)
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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.