Marine Weather and Tides
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 5:52AM||Sunset 8:20PM||Monday May 22, 2017 10:07 PM PDT (05:07 UTC)||Moonrise 3:01AM||Moonset 3:50PM||Illumination 7%|
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|PZZ545 Point Reyes To Pigeon Point To 10 Nm- 944 Pm Pdt Mon May 22 2017 |
Tonight..SW winds 10 kt. Wind waves 3 ft late in the evening... Becoming 2 ft or less. NW swell 3 ft at 9 seconds. Patchy fog after midnight.
Tue..SW winds 10 kt. Wind waves 2 ft or less. NW swell 3 ft at 9 seconds. Patchy fog in the morning.
Tue night..SW winds 10 kt. Wind waves 3 ft in the evening... Becoming 2 ft or less. NW swell 3 ft at 8 seconds. Patchy fog after midnight.
Wed..S winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft at 11 seconds. Patchy fog in the morning.
Wed night..S winds 10 to 20 kt. Wind waves 2 to 4 ft. NW swell 3 to 5 ft at 11 seconds.
Thu..S winds 10 to 20 kt. Wind waves 2 to 4 ft...becoming 2 ft or less. NW swell 3 to 5 ft.
Fri..W winds 10 kt. Wind waves 2 ft or less. NW swell 3 to 5 ft.
Sat..W winds 5 to 15 kt. Wind waves 1 to 3 ft. NW swell 3 to 4 ft. Patchy fog.
...san francisco bar/fourfathom bank forecast..... In the deep water channel...combined seas 2 to 3 ft with a period of 15 seconds. Across the bar...combined seas 3 to 5 ft with a period of 15 seconds. Maximum ebb current of 1.7 knots at 01:30 am Tuesday and 1.1 knots at 01:54 pm Tuesday.
|PZZ500 944 Pm Pdt Mon May 22 2017 |
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Surface high pressure over the eastern pacific will strengthen from tonight into Wednesday morning keeping northwesterly winds going over the outer waters. A surface ridge of high pressure over the central coast will cause winds over the inner coastal waters to be primarily light southwesterly through Tuesday. Except for the Monterey bay onshore winds will be gusty over the bays each afternoon and evening at least through mid-week.
7 Day Forecast for Marine Location Near Half Moon Bay, CAHourly EDIT Help
Area Discussion for - San Francisco/Monterey Bay Area, CA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus66 kmtr 230400|
area forecast discussion
national weather service san francisco bay area
900 pm pdt Mon may 22 2017
Synopsis Look for cooler conditions through most of the week as
a onshore flow combines with the marine layer. Minor warming is
then expected during the upcoming weekend especially for inland
Discussion As of 9:00 pm pdt Monday... No forecast updates
planned for this evening with about a 1500 foot marine layer in
place along the immediate coast. Low clouds making their way
through the golden gate and into the berkeley hill as well as
spreading inland around the monterey bay region. Inland areas that
reached the 90s today will see more significant cooling for
Tuesday as onshore flow continues to increase with a deepening
marine layer in response to upper troughing aloft.
All available MOS data suggests continued cooling trend through
midweek for inland areas with robust onshore winds in place and
likely persistent stratus around the coast and bays. The trend
will be for near or below normal temperatures for much of the rest
of the work week.
Looking ahead to the long holiday weekend, long range models
suggest a seasonable weather pattern with dry and near normal
Prev discussion As of 1:15 pm pdt Monday... As expected temperatures
are running cooler for all locations away from the coast today
with many spots 5 to 12 degrees less than values from Sunday.
Current readings show a wide range from 50s and 60s to parts of
the coast with 70s and 80s inland. Still a few hours of heating,
so would expect the warmest inland spots to again get into the
90s, however the number of locations should be less than
yesterday. Satellite shows widespread clouds along the water and
with the minor onshore flow expected to continue, likely that many
of the local beaches will see little to no sunshine today.
Tonight will be a near repeat of last night with patchy fog along
the coast and to some inland spots. Lows will mostly be in the 50s
with 60s above 1500 feet.
Synoptically the ridge of high pressure in charge will begin to
flatten out through the week as a system dives down from canada
and works into the northern rockies. 500 mb heights will drop from
587 dm today to 573 dm by Thursday. Inland locations that have|
been in the 90s the past few days will drop back into the upper
60s to the lower 70s. Closer to the coast widespread mid 50s to
mid 60s can be expected. With the onshore flow in place, much of
the week could by quite grey at the coast.
Longer range guidance shows the ridge trying to rebuild by the
weekend although heights will be less than the past few days. By
Sunday inland spots will be back in the mid 70s to mid 80s away
from the coast with 60s to mid 70s near the water.
Aviation As of 5:34 pm pdt Monday... The marine layer depth
varies from 700 feet over the bay area to 1200 feet over the north
central coast late this afternoon. The smx-sfo gradient is 2.3
mb; at present as well as tonight into Tuesday the NAM forecasts a
neutral gradient, applying a 2 mb correction a southerly component
to the coastal winds is likely to continue into Tuesday. The sfo-
sac gradient is 2 mb which is line with the nam, which predicts
stronger onshore gradient/wind developing Tuesday afternoon and
evening with sfo-sac gradient near 4 mb, similarly a moderate to
strong gradient and wind develops again Wednesday.
00z tafs for the bay area indicateVFR except southerly flow will
likely bring lifr/vlifr CIGS and vsbys to ksts late tonight and
Tuesday morning. Also, for monterey bay area ifr/lifr is likely
to develop this evening. Moderate to high forecast confidence.
Vicinity of ksfo...VFR. W-nw winds with occasional gusts to 20-25
knots til 05z this evening. Gusty w-nw winds resume Tuesday afternoon
Sfo bridge approach... Similar to ksfo.
Monterey bay terminals...VFR then tempo ifr/lifr 02z-07z then ifr/lifr
prevailing tonight into late Tuesday morning.VFR returns late Tuesday
morning and afternoon, onshore winds will likely bring stratus and
fog back Tuesday evening.
Marine As of 08:51 pm pdt Monday... Northerly flow will persist
with light to moderate winds and small seas. High pressure will
strengthen north of the region increasing winds midweek. Winds
will be strongest north of point reyes, especially the outer
Tngt Sca... Sf bay until 9 pm
public forecast: rww
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Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
Wind History for Redwood City, CA(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Half Moon Bay Airport, CA||3 mi||72 min||N 0||5.00 mi||Fog/Mist||54°F||51°F||94%||1015.6 hPa|
|San Francisco, San Francisco International Airport, CA||12 mi||71 min||WNW 14||10.00 mi||A Few Clouds||56°F||51°F||84%||1013.9 hPa|
|San Carlos Airport, CA||13 mi||80 min||WNW 8||10.00 mi||A Few Clouds||68°F||50°F||53%||1013.5 hPa|
|Palo Alto Airport, CA||19 mi||80 min||NW 9||10.00 mi||Clear||61°F||57°F||88%||1013.9 hPa|
|Oakland, Metro Oakland International Airport, CA||21 mi||74 min||NW 9||10.00 mi||Partly Cloudy||58°F||54°F||87%||1014.3 hPa|
|Mountain View, Moffett Field, CA||23 mi||71 min||NW 6||10.00 mi||Fair||63°F||57°F||81%||1014.4 hPa|
|Hayward, Hayward Air Terminal, CA||23 mi||73 min||NW 7||10.00 mi||Fair||61°F||50°F||67%||1014.9 hPa|
Wind History from SFO (wind in knots)
|1 day ago||W||W||W||W||W||W||W||W||W||NW||Calm||N||N||NW||NW||NW||W||W||W||W||W||NW||NW||W|
|2 days ago||W||W||W||W||W||W||W||W||W||NW||NE||NE||N||NE||N||N||NW||NW||W||W||W||NW||NW||W |
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
|Half Moon Bay |
Click for Map
Tue -- 03:24 AM PDT -0.13 feet Low Tide
Tue -- 04:39 AM PDT Moonrise
Tue -- 05:54 AM PDT Sunrise
Tue -- 09:45 AM PDT 4.29 feet High Tide
Tue -- 03:09 PM PDT 1.19 feet Low Tide
Tue -- 05:59 PM PDT Moonset
Tue -- 08:19 PM PDT Sunset
Tue -- 09:24 PM PDT 6.00 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|San Mateo Bridge |
Click for Map
Tue -- 03:06 AM PDT -1.90 knots Max Ebb
Tue -- 04:38 AM PDT Moonrise
Tue -- 05:53 AM PDT Sunrise
Tue -- 06:25 AM PDT 0.01 knots Slack
Tue -- 09:10 AM PDT 1.92 knots Max Flood
Tue -- 12:39 PM PDT -0.01 knots Slack
Tue -- 03:31 PM PDT -1.39 knots Max Ebb
Tue -- 05:58 PM PDT Moonset
Tue -- 06:22 PM PDT 0.01 knots Slack
Tue -- 08:18 PM PDT Sunset
Tue -- 09:08 PM PDT 1.84 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  Help
|Weather Map ||IR Satellite Image from GEOS|
GOES Local Image of CentralWestCoast EDIT
Wind Forecast for San Francisco/Monterey Bay Area, CA (1,6,7,8)(on/off)  Help
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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.