Friday, September25, 2020
Privacy Policy
L-36.com

Marine Weather and Tides
Belmont, CA

Version 3.4
NOTICE
8/26/2020 The 7 day forecast is taking about 5 seconds to load but it will eventually load. NOAA is still working on it.
8/18/2020 NOAA continues to have trouble. Wind guest will occasionally be left off graphs. I am working with NOAA to resolve the issue.
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.

Sunrise 6:58AMSunset 7:02PM Friday September 25, 2020 5:22 PM PDT (00:22 UTC) Moonrise 3:02PMMoonset 12:00AM Illumination 63% Phase: Waxing Gibbous; Moon at 9 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
PZZ531 San Francisco Bay South Of The Bay Bridge- 233 Pm Pdt Fri Sep 25 2020
Today..W winds 5 to 10 kt, increasing to 10 to 20 kt with gusts up to 25 kt this afternoon.
Tonight..W winds 10 to 20 kt with gusts up to 25 kt.
Sat..W winds 10 to 20 kt with gusts up to 25 kt.
Sat night..W winds 5 to 15 kt.
Sun..NW winds up to 10 kt.
Sun night..NE winds up to 10 kt.
Mon..NW winds 5 to 15 kt.
Tue..W winds 5 to 15 kt.
PZZ500 233 Pm Pdt Fri Sep 25 2020
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Moderate to locally gusty northwest winds across the coastal waters through Saturday will bring hazardous conditions for small craft vessels. In addition, a larger long period northwest swell will continue to move through the waters through today before diminishing overnight and through Saturday. Winds will diminish Sunday across the waters but remain locally moderate. Winds are forecast to shift offshore on Monday with locally gusty offshore winds through coastal gaps.


7 Day Forecast for Marine Location Near Belmont, CA
   Hourly   EDIT   Help
location: 37.52, -122.28     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS66 KMTR 252346 AFDMTR

Area Forecast Discussion National Weather Service San Francisco Bay Area 446 PM PDT Fri Sep 25 2020

SYNOPSIS. Quiet weather to wind out the work week with sunny skies and seasonable temperatures. Noted warming trend starts by Saturday afternoon as offshore winds begin to develop. Offshore winds increase Saturday night into Sunday morning with Red Flag Warnings now in effect for the North and East Bay hills for critical fire weather conditions. Winds will ease on Sunday but hot and dry weather across the region. A second burst of offshore winds Sunday night into Monday morning with very warm and dry air in place. Continued unseasonably hot and dry Monday and Tuesday with only gradual cooling by midweek. West coast ridge stays in place through early October with no rain in sight for the Bay Area.

DISCUSSION. as of 1:45 PM PDT Friday . The latest water vapor imagery captures the moisture plume moving into the PAC NW (including far northern California) this afternoon as a cold front makes its way ashore. Meanwhile over our region, onshore flow has allowed for another day of seasonal temperatures. Clear skies are expected for most of the CWA for the rest of the afternoon, while high-based clouds occasionally roll their way overhead. For tonight, rinse and repeat to last night's conditions. Unfortunately following this fair weather day, the warming trend looks set to get going by tomorrow.

The GFS and ECMWF guidance builds the upper-level PAC ridge and brings it up to the West Coast through Saturday, introducing 591 dm heights back into the CWA. As it does so, high confidence that it will build to 592-595dm 500 hPA and for its axis to remain just offshore through early Tuesday. NAM 850 hPa temps quickly build across the CWA Saturday afternoon, surpassing 20 C over most of the region. The culmination of the upper-level ridge and the surface thermal trough will result in hot conditions in the interior and warm conditions along the coast, with Sunday and Monday looking like the hottest days during this setup. Expecting Sunday and Monday temps to range between 90-102 F in the interior and for coastal temps to stay around the 80s F. It should be noted that we will once again observe a notable temperature gradient over SF, as the western side of the city is progged to reach the upper 70s while downtown and the high-terrain locations of SF County may make it up to 90 F, especially by Monday.

On top of hot temperatures this weekend, the position of this upper- level ridge with respect to the deepening upper-level trough over the center CONUS will play out in the form of this weekend's inside- slider.

The latest runs on the NAM have suggests that northerly/northeasterly offshore winds will begin during late Saturday evening, with previous local WRF runs depicting the 925 hPa wind shift just after 2Z Sunday (7PM Saturday) over the North Bay before permeating and mixing down into the East Bay hills as well, especially during the overnight period from Sunday night going into Monday morning. Will be keeping an eye on later runs of the WRF as we get closer to the event start should any other modifications be required for our primary areas of concern.

The Red Flag warning is set to start at 9pm Saturday night for the North and East Bay hills as well as the East Bay interior valleys. The strongest winds are still looking to remain at higher terrain locations, and as such locations below 1000 ft will not experience the same windy conditions. That being said, these winds aloft will substantially dry out the airmass, resulting in low RHs all across the CWA. Initially, expecting RH values in the 30-35% range across most of those higher-terrain locations overnight Saturday into Sunday morning, but conditions will only continue to dry out through Sunday. As such, high confidence for there being little, if any, fog Sunday morning across the Bay Area. Although there may be some patchy spots along the Monterey Peninsula southward given that the dry air mass will take some time to get that far into our CWA.

The dry air mass will continue to decimate RH values through the day, dropping them down into the teens across the higher-terrain North Bay and East Bay hills overnight Sunday into Monday. It is this period where the greatest fire weather concerns are currently progged as such dry conditions associated with this offshore flow will make for dangerous fire start conditions. As such, the Red Flag Warning is currently out until Monday morning; offshore winds will dominate the region until at least Monday morning when winds area- wide are expected to shift to a more southerly component as the upper-level ridge settles over the northwestern corner of Nevada.

In terms of air quality, these offshore winds will help to also introduce smoke from the August Complex back down to the North Bay and even parts of the SF Peninsula. Thankfully, the smoke canopy we are dealing with right now is nowhere near as large as what was observed during our prolonged smoke situation from a couple of weeks ago.

For the latest on air quality concentrations in the Bay Area, be sure to follow the Bay Area Air Quality District. And for all other locations within the CWA, including the Central Coast, be sure to refer to AirNow. For the latest on active wildfires in the area, please refer to CALFIRE and your local Sheriffs Office.

Looking ahead, GEFS and ECMWF ensemble members are in good agreement that this weekend's upper-level ridge over the West Coast will settle over the PAC NW, weaken, and amplify over most of the Mountain West. As such, temps will likely remain above average through the end of the month, with the ensembles suggesting that temps for those days will remain below what we are expecting for this upcoming weekend. Given that the California coast will also be on the side of the upper-level ridge with southerly flow, cannot rule out the slight potential for the development of a southerly surge towards the end of the month. Will keep an eye on it following the inside-slider event, but for now there is low confidence on that. Beyond the end of the month, long-range guidance shows that we may not receive much, if any, precipitation through the first week of October either as this Western US Ridge- Eastern US Trough set up looks set to continue for quite some time. Temps will likely remain above average for some time as well, assuming there is no notable southerly surge. Stay tuned.

AVIATION. As of 04:45 PM PDT Friday . For the 00z TAFs. VFR. Winds are currently onshore with occasional stronger gusts. The marine layer will be shallow overnight, with limited impacts around the region. As the next air mass moves over the Pacific Northwest, the prevailing pattern changes to stronger offshore flow. As the wind shifts direction from W to NW to NNE overnight and into Saturday morning, increasing chances for LLWS, particularly in the North Bay possible. As stronger NNE winds are expected through Monday morning there is a chance for more widespread LLWS impacts across the Bay Area terminals that will be monitored through Monday morning.

Vicinity of KSFO . VFR with strong onshore wind gusts up to 30 kts. As winds reduce overnight, but remain breezy, the marine layer will be shallow for limited cloud cover expected, lingering around 1000 feet. Best chances for thicker clouds early Saturday morning between 10-16z. VFR forecast for Saturday as winds with stronger gusts are forecast yet again.

SFO Bridge Approach . Similar to KSFO.

Monterey Bay Terminals . VFR with onshore, breezy winds. Cloud cover returns this evening after 3z for IFR conditions, with less reach farther inland. VFR forecast after 17z with breezy winds.

BEACHES. as of 4:00 PM PDT Thursday . A deep low in the Gulf of Alaska has produced a large long-period swell train that will impact the coastline through tomorrow afternoon. Swells by this afternoon 10 to 12 ft with a 15 to 16 second period. The main impacts will be increased wave heights breaking near the shoreline and an increased risk of rip currents developing along coastal beaches. This may produce breaking wave heights in the surf zone of 15 to 20 feet, particularly at west to northwest facing beaches. Therefore, a Beach Hazards Statement has been issued from 5 PM PDT this afternoon until 2 PM PDT Friday. With the increase in temperatures inland expected late in the week, beachgoers should be mindful of the increased wave activity and rip currents.The wave activity is forecast to subside into Friday evening.

CLIMATE. Here are the record high temperatures for Saturday through Monday .

. SATURDAY . SUNDAY . MONDAY SANTA ROSA . 103 in 2009 . 103 in 2010 . 104 in 2010 KENTFIELD . 99 in 2016 . 103 in 1921 . 102 in 1921 NAPA . 105 in 1963 . 101 in 1958 . 102 in 1966 RICHMOND . 97 in 2019 . 97 in 2010 . 97 in 2010 LIVERMORE . 103 in 1952 . 105 in 1963 . 105 in 2010 SAN FRANCISCO . 94 in 1992 . 93 in 2010 . 95 in 1966 SF AIRPORT . 95 in 1958 . 96 in 2010 . 95 in 2010 REDWOOD CITY . 99 in 1963 . 97 in 2010 . 98 in 2010 HALF MOON BAY . 90 in 1970 . 89 in 1966 . 91 in 1958 OAKLAND DOWNTOWN . 93 in 2016 . 95 in 1973 . 92 in 2010 SAN JOSE . 98 in 2016 . 98 in 1921 . 99 in 2010 GILROY . 104 in 1963 . 108 in 1963 . 101 in 1963 SANTA CRUZ . 101 in 1970 . 103 in 2010 . 100 in 1917 SALINAS . 101 in 2016 . 102 in 2010 . 99 in 1970 KING CITY . 105 in 1963 . 107 in 2010 . 102 in 1973

MARINE. as of 02:33 PM PDT Friday . Moderate to locally gusty northwest winds across the coastal waters through Saturday will bring hazardous conditions for small craft vessels. In addition, a larger long period northwest swell will continue to move through the waters through today before diminishing overnight and through Saturday. Winds will diminish Sunday across the waters but remain locally moderate. Winds are forecast to shift offshore on Monday with locally gusty offshore winds through coastal gaps.

MTR WATCHES/WARNINGS/ADVISORIES. Tngt. High Surf Advisory . CAZ530 SCA . Pt Arena to Pt Reyes 0-10 nm SCA . Pt Reyes to Pigeon Pt 0-10 nm SCA . Pigeon Pt to Pt Pinos 0-10 nm SCA . Pt Pinos to Pt Piedras Blancas 0-10 nm SCA . Pt Arena to Pigeon Pt 10-60 nm SCA . Pigeon Pt to Pt Piedras Blancas 10-60 nm SCA . Mry Bay



PUBLIC FORECAST: Diaz AVIATION: DK MARINE: DRP

Visit us at www.weather.gov/sanfrancisco

Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea


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 4 mi53 min W 14 G 17 71°F 74°F1016.6 hPa
AAMC1 - 9414750 - Alameda, CA 17 mi53 min W 8.9 G 12 68°F 69°F1016 hPa
LNDC1 19 mi53 min WSW 8 G 9.9 68°F 1015.7 hPa
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 20 mi53 min SSW 7 G 8
PXOC1 - 9414311 - San Francisco (Pier 1), CA 20 mi53 min WSW 9.9 G 18 68°F 1014.5 hPa
OBXC1 20 mi53 min 70°F 57°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 20 mi53 min S 4.1 G 6 71°F 1015.6 hPa
PXSC1 21 mi53 min 69°F
FTPC1 - 9414290 - San Francisco, CA 22 mi53 min WSW 9.9 G 18 64°F 64°F1015.9 hPa
46237 - San Francisco Bar, CA (142) 26 mi53 min 58°F8 ft
TIBC1 - Tiburon Pier, San Francisco Bay, CA 27 mi36 min Calm 71°F 1015 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 27 mi53 min SE 7 G 9.9 68°F 1015.7 hPa
RCMC1 - 9414863 - Richmond, CA 29 mi53 min N 1 G 1.9 72°F 65°F1015.2 hPa
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 34 mi33 min NW 18 G 21 62°F 10 ft1017.3 hPa60°F
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 34 mi33 min WNW 16 G 18 60°F9 ft1016.9 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 37 mi53 min W 12 G 16 76°F 70°F1014.4 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 37 mi53 min WSW 11 G 13 74°F 1014.6 hPa
UPBC1 37 mi53 min WNW 12 G 16
PCOC1 - 9415144 - Port Chicago, CA 39 mi53 min W 12 G 15 77°F 70°F1014 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 42 mi53 min NW 9.9 G 13 78°F 1013.8 hPa
SFXC1 - San Francisco Bay Reserve, CA 49 mi98 min SW 8

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
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
3
PM
4
PM
Last
24hr
W13
W15
G21
W15
NW13
W14
G17
W7
G11
W7
G10
SW13
G17
W11
G15
W9
W10
G15
W10
G14
W6
--
NW5
S4
NW6
G9
N2
N4
N5
N4
G9
W10
G13
W14
W14
G18
1 day
ago
NW13
G17
W13
G16
W11
G14
W10
G14
W6
G9
SW3
NW6
W4
NW4
SE3
SE3
NW5
NW4
G7
NW4
S3
SE1
N4
N3
N10
NW9
G13
NW11
G15
NW12
G17
NW16
NW13
2 days
ago
W13
W10
W11
G14
W6
W4
NW6
G10
SW3
SE1
--
S2
W3
SW1
NW1
S1
SE3
SE3
NW1
N1
N3
NW9
G12
NW15
NW15
NW14
G17
NW18

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Carlos Airport, CA2 mi36 minWSW 10 G 1610.00 miA Few Clouds72°F50°F47%1016.3 hPa
San Francisco, San Francisco International Airport, CA8 mi27 minW 21 G 3010.00 miPartly Cloudy and Breezy67°F55°F66%1015.7 hPa
Palo Alto Airport, CA9 mi96 minNW 13 G 2010.00 miClear75°F55°F50%1015.9 hPa
Half Moon Bay Airport, CA12 mi28 minNNW 15 G 185.00 miFair with Haze64°F57°F78%1017.3 hPa
Hayward, Hayward Air Terminal, CA13 mi29 minW 1210.00 miFair72°F55°F57%1016.8 hPa
Oakland, Metro Oakland International Airport, CA13 mi30 minW 1310.00 miA Few Clouds73°F57°F57%1015.7 hPa
San Jose, San Jose International Airport, CA21 mi30 minN 1210.00 miPartly Cloudy74°F53°F48%1015.5 hPa

Link to 5 minute data for KSQL

Wind History from SQL (wind in knots)
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
3
PM
4
PM
5
PM
Last 24hrW16W13
G16
W7W7W11W8
G14
W8W9W8W11
G18
W10W8N4W3CalmCalmW3N5NE5NE5W8
G16
W13W11
G17
SW10
G16
1 day agoW14W10
G14
W9W5W5CalmNW3NW3CalmCalmCalmNW7NW4CalmCalmCalmNE4N5NW7NW11W11NW14
G18
W14W14
G20
2 days agoW12
G15
W12W104W5W4SW3NE4CalmCalmCalmCalmCalmCalm--CalmCalmCalmNW8NW10NW11NW8W15W15

Tide / Current Tables for Smith Slough, San Francisco Bay, California
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Smith Slough
Click for Map
Fri -- 12:47 AM PDT     Moonset
Fri -- 03:12 AM PDT     0.06 feet Low Tide
Fri -- 06:59 AM PDT     Sunrise
Fri -- 09:59 AM PDT     6.89 feet High Tide
Fri -- 03:29 PM PDT     3.02 feet Low Tide
Fri -- 04:01 PM PDT     Moonrise
Fri -- 07:00 PM PDT     Sunset
Fri -- 08:34 PM PDT     7.74 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
11
pm
2.71.40.50.10.31.12.445.46.56.96.55.74.63.63.13.13.95.26.67.67.77.16

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
Fri -- 12:47 AM PDT     Moonset
Fri -- 03:21 AM PDT     0.00 knots Slack
Fri -- 06:31 AM PDT     1.56 knots Max Flood
Fri -- 06:59 AM PDT     Sunrise
Fri -- 09:59 AM PDT     -0.00 knots Slack
Fri -- 12:51 PM PDT     -0.62 knots Max Ebb
Fri -- 03:33 PM PDT     0.00 knots Slack
Fri -- 04:02 PM PDT     Moonrise
Fri -- 06:08 PM PDT     0.93 knots Max Flood
Fri -- 07:00 PM PDT     Sunset
Fri -- 09:03 PM PDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
11
pm
-1.5-1.3-0.9-0.30.61.21.51.51.20.7-0-0.4-0.6-0.6-0.5-0.30.30.70.90.90.60-0.6-1.1

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


Cookie Policy:
This website uses cookies to save your settings. No personal information is saved. I do not collect statistics on your visit. You can disable cookies in your browser if you like but it is not recommended for this site. I do not sell cookies. Go to a bakery for that. In fact I do not sell anything. To disable cookies from L-36.com, please refer to the Help button in your browser.
Privacy Policy:
I do not sell or share any user data or anything else for that matter. The only personal information I save is in the site log which has a line for each page view which includes the IP address your browser sends in the header as well as which page you requested. I use this to block hackers and other bad actors. I do not use this raw data to create profiles on users. I periodically delete the log files. Google supplies the ads on this site. Because I do not track who you are, I cannot customize how these ads are served. They may be personalized to improve the ad experience. If you do not want personalized ads, please adjust the settings on the Google site HERE.
. NOTE: The best I can determine, this site is not subject to CCPA but I am doing my best to comply anyway. 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 numerous 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.