Wednesday, September26, 2018 L-36.com


Marine Weather and Tides
Novato, CA

Version 3.4
What's New / NOTES
9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 7:00AMSunset 7:02PM Tuesday September 25, 2018 10:33 PM PDT (05:33 UTC) Moonrise 6:48PMMoonset 6:26AM 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
    EDIT      (on/off)   Help
PZZ530 San Pablo Bay Suisun Bay The West Delta And San Francisco Bay North Of The Bay Bridge- 815 Pm Pdt Tue Sep 25 2018
Tonight..SW winds 5 to 15 kt. Gusts up to 25 kt this evening.
Wed..SW winds 5 to 15 kt.
Wed night..SW winds 5 to 15 kt.
Thu..SW winds 10 to 20 kt with gusts up to 25 kt.
Thu night..SW winds 10 to 20 kt with gusts up to 30 kt.
Fri..SW winds 10 to 20 kt with gusts up to 25 kt.
Fri night..SW winds 10 to 20 kt with gusts up to 25 kt.
Sat..SW winds 5 to 15 kt.
Sun..SW winds up to 10 kt.
PZZ500 815 Pm Pdt Tue Sep 25 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Light to moderate west to northwest winds will continue through the week as an upper ridge remains off the coast of the pacific northwest. Low pressure will then move in resulting in weak southerly winds by this coming weekend.


7 Day Forecast for Marine Location Near Novato, CA
   Hourly   EDIT   Help
location: 38.1, -122.59     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus66 kmtr 260524
afdmtr
area forecast discussion
national weather service san francisco bay area
1024 pm pdt Tue sep 25 2018

Synopsis Warm offshore flow will persist in the hills and for
inland valleys at least through midweek. The coast and coastal
valleys will still be under the influence of cooler onshore flow
with a marine layer in place. A cooling trend for all areas Friday
into the weekend as a mainly dry upper trough approaches the
region. Some indications for rain chances across northern california
by early next week.

Discussion As of 9:15 pm pdt Tuesday... Mainly clear skies
prevail across inland areas this evening while the coast and
coastal valley remain shrouded under a 1000 foot marine layer.

Coastal regions saw minimal to no clearing today as the gradients
along the coast remained primarily onshore. Temperatures cooled
slightly across the bay area today as a result of the onshore
gradient which resulted in moderate inland intrusion of stratus
this morning. Meanwhile southern inland locations that were not
affect by the relatively shallow marine layer saw temperatures
warm slightly. Temperatures finished off the day with highs in the
60s along the coast, 70s around the bay and mid 80s to mid 90s
over inland locations.

Warm and dry weather conditions will continue through Thursday as
high pressure at the surface continues to ridge across the
pacific northwest and into the great basin and a surface trough
persists along the california coast. This will result in light
offshore flow, warm temperatures and low relative humidities
across the interior and hills.

A pattern change remains on track for Friday on into the weekend
with cooler temperatures and a chance of rain by the beginning of
next week.

The forecast remains on track. No updates expected at this time.

From previous discussion... A rex block centered approximately 900
miles wnw of san francisco is acting as a 1750 mile meridional
(north to south) barrier in the atmospheric flow. Water vapor
imagery shows moisture wrapping over the north of the barrier
through the gulf of alaska before rotating into the pacific
northwest. At the same time, a band of subtropical moisture
associated with the upper low (which forms the southern half of
the rex block) is rotating counterclockwise into southern baja
california south of the rex block. Meanwhile, a dry slot of air is
positioned over the san francisco and monterey bay area in
between the moister air rotating into the western CONUS from both
the south and northern flanks of the rex block.

At the most simple level, a rex block consists of a high pressure
positioned north of a low pressure. Both the high and low pressure
circulations present in the current rex block will play a role in
the weather through the next several days. The high pressure
portion of the rex block has and will continue to result in an
increase of offshore winds, warmer temperatures, dry inland
conditions, and a compressed marine layer near the coast as it
wobbles over northern california. The rex block breaks down late
in the work week, freeing up the low pressure system to slide over
northern california through the early weekend. This will bring a
cooling trend, increased onshore flow, and even a slight chance of
some very light rainfall over the extreme northern stretches of
sonoma county. The medium to longer term models are in fairly good
agreement of this scenario playing out, albeit, with the bulk of
any rainfall remaining farther northward over extreme northwest
california. Any accumulations will be measured in the low
hundredths range.

Low model to model and run to run model consistency beginning
early next week. The GFS and euro both agree that the weather
pattern will remain progressive and unsettled for early next week.

Both models feature a cool, wet trough arriving behind the
remnants of the rex block features by Monday morning in addition
to an eastern pacific tropical system moving into the vicinity of
the region. Neither model seems to know what to make of these two
features. The 00z euro was extremely wet and progressive for our
region, however, the 12z euro has slowed down and keeping the
system corralled along the coastline, rather than directly over
the san francisco bay area. The GFS is playing a completely
different tune, shunting the upper low and moisture farther south,
over southern california. None of these solutions will likely be
the one that actually plays out due to the unknown variable of the
tropical system lingering farther offshore. That said, have
nudged chance of rain into the slight chance category for early
next week. Expect to see the forecast change rapidly as both the
approaching trough arriving from the northwest and developing
tropical cyclone arriving from the southwest come into better
focus.

Aviation As of 10:24 pm pdt Tuesday... For 06z tafs. Marine
layer remains at around 1000 to 1200 feet in depth with stratus
along the coast and moving down the salinas valley. Given similar,
if not more extensive, cloud cover than this time last night
sticking with a persistence forecast. Low CIGS expected at most
sites aside from ksjc and klvk with patchy fog in the north bay
and reduced visibility possible at the monterey bay sites.

Generally light winds overnight becoming onshore in the afternoon
10-15 kt.

Vicinity of ksfo...VFR with light winds. Possible MVFR ifr cigs
late tonight 10z-12z.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals... Ifr lifr CIGS through 16z-18z tomorrow
morning with possible ifr lifr vis.

Fire weather As of 9:28 pm pdt Tuesday... The red flag warning
for the north and east bay hills was allowed to expire at 5 pm
this evening. Nonetheless conditions will remain warm and dry with
localized breezy conditions across the hills through tonight.

Winds are forecast to continue diminishing and will remain below
warning criteria. Note, very dry conditions will prevail
especially across elevated terrain above the 1000 feet marine
layer. Cooler temperatures and higher relative humidity values
will return Friday as a cooler and wetter airmass moves in.

Marine As of 8:15 pm pdt Tuesday... Light to moderate west to
northwest winds will continue through the week as an upper ridge
remains off the coast of the pacific northwest. Low pressure will
then move in resulting in weak southerly winds by this coming
weekend.

Mtr watches warnings advisories
Tngt None.

Public forecast: cw
aviation: as
marine: as
fire weather: cw
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
TIBC1 - Tiburon Pier, San Francisco Bay, CA 16 mi41 min Calm 58°F 1014 hPa (+1.0)
RCMC1 - 9414863 - Richmond, CA 16 mi34 min 63°F
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 18 mi34 min WSW 4.1 G 5.1 64°F 1013.1 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 18 mi34 min S 12 G 14 58°F 1014.3 hPa
FTPC1 - 9414290 - San Francisco, CA 21 mi40 min W 2.9 G 6 54°F 61°F1014.7 hPa
46237 - San Francisco Bar, CA (142) 22 mi34 min 58°F3 ft
PRYC1 - 9415020 - Point Reyes, CA 22 mi34 min Calm G 1.9 58°F1014.4 hPa (+0.9)
PXSC1 23 mi40 min 56°F 56°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 23 mi34 min SW 5.1 G 12 55°F 1013.4 hPa (+1.4)
OKXC1 - 9414776 - Oakland (Berth 34), CA 24 mi34 min W 7 G 8.9 56°F 1014.4 hPa (+1.3)
OBXC1 24 mi34 min 56°F 56°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 25 mi34 min W 7 G 8
MZXC1 - 9415102 - Martinez-Amorco CA 25 mi34 min WNW 8 G 12 67°F1013.2 hPa (+1.2)
AAMC1 - 9414750 - Alameda, CA 27 mi40 min W 7 G 8 57°F 66°F1014.6 hPa
LNDC1 27 mi34 min NNE 1.9 G 4.1 58°F 1014.4 hPa (+1.4)
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 27 mi24 min W 3.9 G 7.8 54°F 55°F1015.3 hPa
PCOC1 - 9415144 - Port Chicago, CA 29 mi34 min WSW 8 G 9.9 64°F 67°F1012.9 hPa (+1.3)
SFXC1 - San Francisco Bay Reserve, CA 31 mi49 min W 8 65°F 1012 hPa46°F
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 37 mi34 min W 8.9 G 14 77°F 1012.1 hPa (+0.8)
46013 - Bodega Bay - 48NM North Northwest of San Francisco, CA 39 mi24 min WSW 1.9 G 5.8 52°F1014.7 hPa
RTYC1 - 9414523 - Redwood City, CA 46 mi34 min NW 2.9 G 4.1 60°F 70°F1015 hPa (+1.5)
46214 - Point Reyes, CA (029) 48 mi34 min 57°F4 ft

Wind History for Richmond, CA
(wind in knots)    EDIT      (on/off)   Help
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
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
Last
24hr
SW2
S5
SW3
W5
SW4
SW4
S2
N2
W2
W1
S3
SE2
G5
S5
S4
S5
NE1
S3
G7
W4
SE5
SE2
SE3
SW1
S2
SE1
1 day
ago
S8
G11
SW5
S7
G11
S5
G9
SW4
G7
SW2
--
NW2
W4
NW3
S1
SE3
SE4
SE5
S4
S6
G9
S6
S2
NW4
W3
G8
SE4
NW4
SE3
G6
S6
2 days
ago
S9
S6
G10
S8
G11
S7
G10
S5
G8
S11
G16
S5
S7
G10
S7
G10
S7
S6
G9
S6
S5
G10
S7
G11
S5
G8
S8
S7
G12
S5
G9

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Novato / Gnoss Field, CA4 mi39 minN 710.00 miFair54°F50°F88%1013.5 hPa
Petaluma Municipal Airport, CA11 mi39 minNW 45.00 miFog/Mist52°F51°F100%1013.9 hPa
Napa, Napa County Airport, CA18 mi40 minSSW 410.00 miFair59°F54°F83%1012.5 hPa

Wind History from DVO (wind in knots)
11
PM
-12
PM
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
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
Last 24hrNW5N6NW4N6N8NW5NW7N6CalmN6N8N4CalmCalm55N12N15N12N11N10NW5N7N5
1 day agoCalmCalmS4CalmCalmCalmNW3CalmCalmCalmCalmCalmCalm4456NE11N10N11
G16
N8N7N8N8
2 days agoCalmCalmCalmCalmCalmCalmCalmCalmN3CalmCalmCalmNE45SE7SE85SW7CalmS7E4NE3CalmCalm

Tide / Current Tables for Hog Island, San Antonio Creek, San Pablo Bay, California
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Petaluma River Approach, San Pablo Bay, California Current
   EDIT      (on/off)   Help   One Week of Data
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


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 (1,6,7,8)
      (on/off)   Help

Ground Weather Radar Station Sacramento, 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.