Thursday, May24, 2018 L-36.com


Marine Weather and Tides
Half Moon Bay, CA

Version 3.4
What's New / NOTES
5/20/2018 -- NOAA is having problems with the data feed that I use to draw the graphs. They are aware of the issue and working to resolve it. Sometimes changing the location by about a mile will give a correct graph. 3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.

Sunrise 5:51AMSunset 8:21PM Thursday May 24, 2018 2:44 PM PDT (21:44 UTC) Moonrise 2:38PMMoonset 2:24AM Illumination 76% Phase: Waxing Gibbous; Moon at 10 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
    EDIT      (on/off)   Help
PZZ545 Point Reyes To Pigeon Point To 10 Nm- 224 Pm Pdt Thu May 24 2018
Tonight..SW winds 5 to 15 kt. Wind waves 1 to 3 ft. W swell 3 to 5 ft at 11 seconds and sw 3 ft at 15 seconds. Chance of showers after midnight.
Fri..S winds 5 to 15 kt. Wind waves 1 to 3 ft. W swell 3 to 5 ft at 11 seconds and sw 3 ft at 15 seconds. Chance of showers.
Fri night..W winds 10 kt...becoming nw 10 to 20 kt after midnight. Wind waves 3 to 5 ft. W swell 3 to 4 ft at 11 seconds and sw 3 ft at 14 seconds. Slight chance of showers in the evening.
Sat..NW winds 15 to 25 kt. Wind waves 3 to 5 ft. NW swell 4 to 6 ft at 11 seconds.
Sat night..NW winds 15 to 25 kt. Wind waves 5 to 7 ft. NW swell 6 to 8 ft at 9 seconds.
Sun..W winds 15 to 25 kt. Wind waves 3 to 5 ft. NW swell 4 to 6 ft.
Memorial day..W winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 4 to 6 ft.
Tue..W winds 20 to 30 kt. Wind waves 3 to 4 ft...increasing to 5 to 7 ft. NW swell 4 to 6 ft.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 3 to 5 ft with a dominant period of 15 to 16 seconds. Across the bar...combined seas 4 to 7 ft with a dominant period of 15 to 16 seconds. Maximum ebb current of 3 knots at 01:13 am Friday and 2.1 knots at 01:13 pm Friday.
PZZ500 224 Pm Pdt Thu May 24 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... High pressure near the coast will keep light to moderate winds over the coastal waters. Gusty winds will be possible this evening north of the bay bridge inside the san francisco bay. Northwest winds increase Friday. Gusty winds will impact the coastal waters this holiday weekend. Mixed seas with a longer period southwest swell and a smaller northwest swell.

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


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus66 kmtr 242037
afdmtr
area forecast discussion
national weather service san francisco bay area
137 pm pdt Thu may 24 2018

Synopsis Cloudy and cool today with increasing chance of
showers tonight into Friday as a late season low passes over the
region. Shower chances end by early Saturday morning. High
pressure builds Sunday through Tuesday with a noted warming and
drying trend.

Discussion As of 1:38 pm pdt Thursday... Overcast conditions
continue to dominate much of the central california coast and san
francisco bay area this early afternoon. The marine stratus
earlier today managed to push well inland to the santa clara-
merced county line at pacheco pass, and south through monterey
county up to the monterey-fresno and monterey-kings county lines.

The healthy marine layer is responding to an approaching upper
level low that will be the main weather story for our region over
the next day or two as it approaches the california coast.

Temperatures this afternoon will remain rather cool for much of
the area blanketed under the clouds. Highs will be in 50s to 60s
along the coast, and 60s to low 70s for interior locations.

Overnight tonight, the aforementioned upper level low will be
within a few hundred miles of the central california coast. As the
low moves eastward, precipitation chances will increase later
tonight and into the day on Friday. Not expecting a widespread
washout by any means, but more or less scattered shower activity.

In terms of convective thunder potential, models are suggesting
some minimal surface-based and mid-level instability with a
notable downward trend from model run-to-run. The latest day 2
storm prediction center convective outlook has actually backed off
on the general thunder area over parts of the state, which
previously had included parts of the north bay. It's still a non-
zero chance, but not looking as likely as earlier. Nonetheless,
the main impacts expected will be wet roadways from the scattered
showers that may impact the Friday commutes. With the scattered
nature of the showers, total rain amounts are expected to remain
light overall with amounts reaching a tenth of an inch or locally
a quarter of an inch for the higher elevations.

Rain chances will begin to diminish overnight Friday and into
Saturday, though can't rule out lingering showers -- particularly
in the north bay -- through midday Saturday. Temperatures will
begin rebounding back toward seasonal normals with noticeable
warming for the interior from Saturday to Sunday. Highs will
likely reach the mid 70s to 80s for the interior by Sunday with
additional warming for Monday as a ridge builds over the eastern
pacific. Can't rule out the potential for some 90s by memorial day
for the interior. Overall it should be a very nice holiday
weekend weather-wise by Sunday and Monday with some clearing even
reaching the beaches. Any beachgoers should always be mindful of
the hazards the pacific ocean presents year-round, including the
cold water temperatures and rip current risks. Always be aware of
your surroundings, and never turn your back to the ocean.

As the ridge shifts inland by Tuesday and Wednesday next week,
temperatures will likely begin a gradual cooling trend. By this
time next week models advertise a trough developing over the west
coast, which would help to reinforce a downward trend in afternoon
highs.

Aviation As of 10:39 am pdt Thursday... Based on latest
satellite trends, webcams and hi-res models forecast will be more
pessimistic than previous forecast. Widespread clouds blanket the
bay area with very slow clearing on the edges. Therefore, put
forecast toward an all day event with MVFR cigs. The next
challenge will be any clearing lifting tonight with approaching
low. Hit or miss showers will develop and impact tonight into
early tomorrow. Vcsh for now given uncertainty.

Overall confidence is medium to low.

Vicinity of ksfo... Decided on an all day stratus event. There
could be some lifting above 2500 feet later today, but will keep
at least bkn in forecast. Vcsh later today and tonight poss.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... MVFR CIGS through the period. Vcsh poss
tonight.

Marine As of 10:33 am pdt Thursday... Light to locally moderate
winds over the coastal waters today as high pressure remains off
the immediate coast. The strongest winds today will be located in
the northern san francisco bay. Northwest winds pick up by mid
day tomorrow and become locally moderate by tomorrow night
through the upcoming weekend. Mixed seas with a longer period
southwest swell and a smaller northwest swell. Increasing winds
later this weekend will bring locally steep fresh swell.

Mtr watches warnings advisories
Tngt Sca... Sf bay until 10 pm
public forecast: rowe
aviation: mm
marine: mm
visit us at

Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
RTYC1 - 9414523 - Redwood City, CA 14 mi75 min WSW 5.1 G 7 57°F 64°F1018.7 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 23 mi75 min W 6 G 8.9 57°F 1017.5 hPa
FTPC1 - 9414290 - San Francisco, CA 23 mi75 min WSW 8 G 11 56°F 56°F1018.7 hPa
AAMC1 - 9414750 - Alameda, CA 23 mi75 min W 7 G 9.9 57°F 62°F1018.5 hPa
46237 - San Francisco Bar, CA (142) 23 mi105 min 55°F5 ft
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 23 mi115 min SE 3.9 G 5.8 55°F 55°F6 ft1018.3 hPa (+0.7)
PXSC1 23 mi75 min 58°F 50°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 24 mi75 min WSW 8.9 G 11
OBXC1 24 mi75 min 56°F 50°F
LNDC1 25 mi75 min W 7 G 9.9 57°F 1018.3 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 25 mi75 min W 5.1 G 7 57°F 1018.4 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi75 min SSW 5.8 G 7.8 54°F 54°F1019.2 hPa53°F
TIBC1 - Tiburon Pier, San Francisco Bay, CA 29 mi82 min WSW 4.1 56°F 1019 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 31 mi75 min SSW 7 G 11 56°F 1018.6 hPa
RCMC1 - 9414863 - Richmond, CA 32 mi75 min S 6 G 9.9 56°F 59°F1018.1 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 42 mi75 min SW 11 G 16 58°F 1017.5 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 43 mi75 min SW 14 G 19 58°F 64°F1017.6 hPa53°F
PRYC1 - 9415020 - Point Reyes, CA 45 mi75 min SSE 2.9 G 7 53°F1018.2 hPa
PCOC1 - 9415144 - Port Chicago, CA 47 mi75 min WSW 13 G 19 60°F 64°F1017.1 hPa
46042 - MONTEREY - 27NM West of Monterey Bay, CA 48 mi115 min SE 3.9 G 5.8 56°F 56°F6 ft1018.6 hPa (+0.5)

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
Last
24hr
W15
W13
G17
W16
W11
G15
W11
W13
G16
W9
G15
W9
NW10
W7
W6
W5
W5
W9
W7
G11
W8
W7
W7
W6
W7
G10
W4
G8
W10
G13
W8
NW2
G6
1 day
ago
W17
G21
W17
G21
W18
W16
G20
W14
G17
W13
W11
W10
W9
G12
W8
W8
G11
W6
W6
G10
W7
W6
W4
S4
W4
W8
W9
W8
W13
W13
G16
W14
G17
2 days
ago
W17
W19
G27
W22
G27
W21
W20
G25
W18
G22
W14
G17
W12
G15
W13
G16
W12
W12
G16
W10
W9
SW8
W7
SW9
G12
W11
W11
W7
G11
W7
G10
W10
G13
W13
G16
W16
W15
G19

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Half Moon Bay Airport, CA3 mi50 minSSW 610.00 miOvercast57°F50°F77%1019 hPa
San Francisco, San Francisco International Airport, CA12 mi49 minW 810.00 miMostly Cloudy63°F46°F56%1018 hPa
San Carlos Airport, CA13 mi58 minWSW 610.00 miOvercast61°F48°F63%1018.3 hPa
Palo Alto Airport, CA19 mi58 minW 610.00 miOvercast61°F50°F68%1017.9 hPa
Oakland, Metro Oakland International Airport, CA21 mi52 minW 810.00 miOvercast59°F48°F67%1018.2 hPa
Mountain View, Moffett Field, CA23 mi49 minN 710.00 miOvercast62°F50°F65%1018.2 hPa
Hayward, Hayward Air Terminal, CA23 mi51 minWNW 710.00 miMostly Cloudy60°F48°F65%1019 hPa

Wind History from SFO (wind in knots)
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
Last 24hrW14W17W15
G21
W14W12W13W8W8W7W7W105SW7W7W7SW4SW6SW7SW3SE5W4W11W11W8
1 day agoSW13W15W14W12W11W11W8SW6SW7SW6SW6SW5SW4W6W5SW4SW4SW5W5W8W11W12W11W11
2 days agoW21W22
G29
W20
G25
W16
G24
W14
G18
W10
G18
W12W13SW10
G18
SW10
G19
W13SW8SW10SW9W8SW9W11W8SW9SW9SW10W10W11W14

Tide / Current Tables for Half Moon Bay, California
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Half Moon Bay
Click for Map
Thu -- 01:45 AM PDT     1.23 feet Low Tide
Thu -- 03:24 AM PDT     Moonset
Thu -- 05:54 AM PDT     Sunrise
Thu -- 07:26 AM PDT     4.07 feet High Tide
Thu -- 01:29 PM PDT     0.57 feet Low Tide
Thu -- 03:38 PM PDT     Moonrise
Thu -- 08:11 PM PDT     5.53 feet High Tide
Thu -- 08:19 PM PDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.91.41.21.62.22.93.6443.52.81.81.10.60.61.123.14.25.15.55.34.63.5

Tide / Current Tables for San Mateo Bridge, South San Francisco Bay, California Current
   EDIT      (on/off)   Help   One Week of Data
San Mateo Bridge
Click for Map
Thu -- 01:34 AM PDT     -1.27 knots Max Ebb
Thu -- 03:23 AM PDT     Moonset
Thu -- 04:41 AM PDT     0.00 knots Slack
Thu -- 05:53 AM PDT     Sunrise
Thu -- 07:26 AM PDT     1.34 knots Max Flood
Thu -- 10:24 AM PDT     -0.00 knots Slack
Thu -- 01:38 PM PDT     -1.25 knots Max Ebb
Thu -- 03:37 PM PDT     Moonrise
Thu -- 04:43 PM PDT     0.01 knots Slack
Thu -- 07:43 PM PDT     1.72 knots Max Flood
Thu -- 08:19 PM PDT     Sunset
Thu -- 10:55 PM PDT     -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1-1.2-1.3-1-0.50.311.31.310.3-0.4-0.9-1.2-1.2-1-0.50.31.11.61.71.50.8-0.1

Weather Map and Satellite Images
       (on/off)   HelpWeather Map
wmap_P
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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for San Francisco/Monterey Bay Area, CA (17,4,5,8)
      (on/off)   Help

Ground Weather Radar Station San Francisco Bay Area, CA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.