Marine Weather and Tides
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 5:45AM||Sunset 8:38PM||Saturday June 23, 2018 2:35 PM PDT (21:35 UTC)||Moonrise 3:35PM||Moonset 2:02AM||Illumination 80%|
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|PZZ530 San Pablo Bay Suisun Bay The West Delta And San Francisco Bay North Of The Bay Bridge- 214 Pm Pdt Sat Jun 23 2018 |
.small craft advisory in effect from late tonight through Sunday evening...
Tonight..SW winds 10 to 20 kt.
Sun..SW winds 15 to 25 kt.
Sun night..SW winds 15 to 25 kt. Patchy fog after midnight.
Mon..SW winds 10 to 20 kt. Patchy fog in the morning.
Mon night..SW winds 10 to 20 kt. Patchy fog after midnight.
Tue..SW winds 15 to 25 kt. Patchy fog.
Wed..SW winds 10 to 20 kt. Patchy fog.
Thu..W winds 10 to 20 kt. Patchy fog.
|PZZ500 214 Pm Pdt Sat Jun 23 2018 |
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... High pressure over the eastern pacific and a thermal trough over inland california will keep gusty northerly winds across the coastal waters through tonight. Gusty winds will generate steep wind waves creating hazardous sea conditions, particularly for small vessels. Winds will subside tonight as a southerly surge pushes northward shifting the winds along the inner coastal waters out of the south. Winds will pick up again on Monday as an upper trough moves through to the north.
7 Day Forecast for Marine Location Near Napa, CAHourly EDIT Help
Area Discussion for - San Francisco/Monterey Bay Area, CA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus66 kmtr 231742|
area forecast discussion
national weather service san francisco bay area
1042 am pdt Sat jun 23 2018
Synopsis Very warm to hot temperatures are forecast for the
interior today as high pressure dominates the weather pattern.
Additionally, offshore winds will develop and result in heightened
fire weather concerns for portions of the region today through
Sunday. Cooling is then expected by Sunday and into early in the
upcoming week with increased onshore flow.
Discussion As of 09:00 am pdt Saturday... Today will be the
hottest day of the year for most inland locations, with widespread
80s to low 100s forecast away from the immediate coast. These
temperatures are generally 12 to 20 degrees above seasonal normal
are due to the presence of a 593dm 500mb high pressure ridge
amplifying along the west coast and the resultant warm air
advection and subsidence aloft. 850mb temperatures are forecast to
rise to around 26c by this afternoon which is about 2 standard
deviations from the norm. While we generally do not see record
high (or low) temperatures until approaching the 3-4 standard
deviation range, one record may fall today -- at concord (102f
record set in 2017 vs 103f forecast). The hottest inland locations
may reach or surpass 105f degrees today, such as at pinnacles
national park or extreme E NE portions of napa, sonoma, contra
costa counties and extreme S SE portions of monterey and san
A heat advisory (sfonpwmtr) is in effect as a result of these
temperatures thru the daylight hours of the day. Stay out of
direct sunlight, stay hydrated, listen to your body for signs of
heat exhaustion, check on vulnerable pets, plants, and populations
through the day, and never leave your child in a hot vehicle.
Also considering visiting the coastal areas today as temperatures
will be much more mild for coastal areas. If you do choose to
visit ocean coastal areas remember that the water is still very
in addition to the heat, dry gusty N NE winds will develop
through the weekend aimed primarily and the north and east bay
hills mountains. Mount diablo has already gusted to 60mph as of
445am this morning, and several other locations in the
aforementioned areas have reached 40 mph. Winds are expected to
weaken slightly during the day today but will pick up again this
evening into tomorrow. As a result of the heat and dry offshore
flow, relative humidity values will drop into the upper single
digits to low teens in the warmest windiest locations by this
afternoon. This means that there is a greatly increased risk that
any new fires that start will spread rapidly. As a result, a red
flag warning is in effect (sforfwmtr) for these areas through
tomorrow. Be mindful of any outdoor activities that could ignite
new fires, such as discarded hot or burning objects from cars,
lighting campfires, barbecues, or fireworks, driving cars over dry
grass, or using anything with a motor including lawn equipment.
Temperatures will cool off tomorrow due to a resurgent marine
layer southerly surge that is forecast to develop. Todays main
forecast challenge is to pin down the timing and positioning of
this southerly surge and to what degree it will help shield from
the heat by tomorrow afternoon. See previous discussion for
additional details on the current forecast package.
Previous discussion As of 03:18 am pdt Saturday... Mostly clear
sky conditions prevail over the region this morning with
temperatures ranging from the 50s at the coast to 70s inland and in
the hills. The exception is over the monterey bay where satellite
imagery is showing low clouds developing. Expecting low clouds to
potentially spread locally inland around the bay through the morning
before retreating back to the coast by early afternoon.
With warming aloft in response to the building ridge, temperatures
will be warmer by at least a few degrees compared to yesterday
afternoon. Thus, a heat advisory has been issued for the interior
and higher elevation locations this afternoon as temperatures warm
into the 90s to around 105 for the hottest inland locations.
Meanwhile, weak onshore flow will keep conditions cooler at the
coast where heat risk will be significantly lower. As previously
mentioned... Residents are advised to limit outdoor activities during
the hottest time of day, stay in air-conditioned areas, keep an eye
on pets and livestock, and drink plenty of water. Never leave kids
or pets in a vehicle unattended for any reason for any length of
time as temperatures will rapidly reach dangerous levels inside of
In addition to the heat, dry offshore flow will develop today and
persist into Sunday, especially in the north bay hills mountains and
across the diablo range. Northerly winds gusting to around 40 mph
will be possible and combine with low relative humidity values to|
produce increased fire weather concerns. Thus, a red flag warning
remains in effect for the aforementioned areas from late this
morning through Sunday evening.
Onshore flow is then forecast to develop along the coast as a
southerly surge works northward up the big sur coast on Sunday. This
will bring cooler conditions first to the coast before spreading
inland through Sunday evening. Offshore winds will also decrease
late Sunday evening in the north bay and east bay hills mountains,
lowering fire weather concerns. Region-wide cooling is then expected
into early in the upcoming week as onshore winds increase and a
marine layer becomes better established over the region.
Aviation As of 10:42 am pdt Saturday... For 18z tafs.VFR
through the period for all sites aside from low cloud development
late tonight along the monterey peninsula. Visible satellite
imagery is showing mainly clear skies across the region with the
exception of low clouds moving northward along the monterey county
coastline. It is uncertain at this time how far north these clouds
will progress. Current high resolution models do not have these
clouds intruding into the monterey TAF sites before late tonight.
Satellite will be monitored and tafs will be updated as necessary.
Onshore winds this afternoon 10 to 15 kt with gusts near 20 kt
possible around the sf peninsula. Occasional mixing down of
offshore winds aloft will also be possible.
Vicinity of ksfo...VFR. Winds becoming onshore with gusts up to
near 20 knots this afternoon and early evening. Scattered low
clouds possible starting early tomorrow morning.
Sfo bridge approach...VFR.
Monterey bay terminals...VFR. MVFR CIGS are possible at some point
this afternoon should the low clouds moving up the monterey county
coastline reach the peninsula and intrude inland. Right now, high
resolution models suggest that the low clouds will remain
away from the terminals and retreat southward before re-surging
up the coast and finally moving in late tonight. Confidence on the
timing of this surge is low and tafs may need to be amended as
conditions change. Otherwise,VFR conditions are expected to
prevail through late tonight. Generally light winds through the
period with locally higher onshore winds at ksns this afternoon
Fire weather As of 3:18 am pdt Saturday... A red flag warning
remains in effect for the north and east bay hills from 11 am
through 8 pm this evening. The main concern will be for hot
inland temperatures and low relative humidity along with moderate
and dry northerly winds. To be clear the weather set-up is very
different and not nearly as critical in terms of winds to the
north bay firestorm last october.
Temperatures will continue to warm this afternoon further drying
out fuels that are running near average in terms of seasonal
dryness. Even more widespread afternoon highs in the 90s and low
100s are expected. As temperatures warm, dry northerly winds will
come down the sacramento valley and spread over napa county
by late this morning with wind gusts between 35-45 mph. Winds
will ease in the afternoon before the north and east bay hills see
another round of increased north winds late this evening into
Sunday. During this time little to no relative humidity recovery
is expected and overnight lows will be warm in the 70s and 80s.
Afternoon highs on Sunday will remain warm to hot, but onshore
flow will return late in the day providing some cooling.
Those spending time outside this weekend are urged to be vigilant
with sources of ignition. Any new fire starts, especially in the
grassy fuels will spread rapidly.
Marine As of 08:18 am pdt Saturday... Gusty northerly winds
will continue into tonight as high pressure sits over the eastern
pacific and a thermal trough resides over california. These winds
will generate steep wind waves creating hazardous sea conditions,
especially for smaller vessels. Winds will subside tonight into
tomorrow as a southerly surge develops by early tomorrow morning
turning the winds southerly over the inner coastal waters.
Mtr watches warnings advisories
Tday Heat advisory... Caz506>508-510>513-516>518
sca... Pt arena to pigeon pt 10-60 nm
sca... Pt arena to pt reyes 0-10 nm
sca... Pt reyes to pigeon pt 0-10 nm
sca... Pigeon pt to pt piedras blancas 10-60 nm
public forecast: drp
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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 Martinez-Amorco Pier, CA(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|Napa, Napa County Airport, CA||6 mi||41 min||SSW 7||10.00 mi||Fair||94°F||46°F||19%||1006.3 hPa|
|Petaluma Municipal Airport, CA||17 mi||60 min||WNW 10||10.00 mi||Fair||95°F||55°F||26%||1007.4 hPa|
|Novato / Gnoss Field, CA||18 mi||60 min||Var 4||10.00 mi||Fair||95°F||51°F||23%||1007.1 hPa|
|Vacaville Nut Tree Airport, CA||18 mi||42 min||NE 14 G 20||10.00 mi||Fair||101°F||42°F||13%||1006.8 hPa|
|Fairfield / Travis Air Force Base, CA||19 mi||37 min||NNE 10||10.00 mi||Fair||99°F||43°F||15%||1007 hPa|
Wind History from APC (wind in knots)
|1 day ago||SW||S||S||S||S||S||S||S||S||SW||Calm||Calm||W||Calm||Calm||Calm||Calm||Calm||SW||SW||S||S||SW||S|
|2 days ago||S||SW||SW||SW|
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of Data
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Sat -- 03:01 AM PDT Moonset
Sat -- 05:46 AM PDT Sunrise
Sat -- 06:06 AM PDT 0.44 feet Low Tide
Sat -- 11:58 AM PDT 5.47 feet High Tide
Sat -- 04:34 PM PDT Moonrise
Sat -- 05:29 PM PDT 1.75 feet Low Tide
Sat -- 08:36 PM PDT Sunset
Sat -- 11:34 PM PDT 7.54 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
EDIT (on/off)  Help One Week of Data
|Mare Island Strait |
Click for Map
Sat -- 01:54 AM PDT -2.34 knots Max Ebb
Sat -- 03:02 AM PDT Moonset
Sat -- 05:45 AM PDT 0.00 knots Slack
Sat -- 05:46 AM PDT Sunrise
Sat -- 09:05 AM PDT 1.25 knots Max Flood
Sat -- 11:31 AM PDT -0.00 knots Slack
Sat -- 01:39 PM PDT -1.51 knots Max Ebb
Sat -- 04:33 PM PDT Moonrise
Sat -- 04:46 PM PDT 0.00 knots Slack
Sat -- 08:34 PM PDT 1.73 knots Max Flood
Sat -- 08:35 PM PDT Sunset
Sat -- 11:42 PM PDT -0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Weather Map and Satellite Images(on/off)  HelpWeather Map
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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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
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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.