Monday, January18, 2021
Privacy Policy
L-36.com

Marine Weather and Tides
San Mateo, 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 7:20AMSunset 5:19PM Monday January 18, 2021 5:13 PM PST (01:13 UTC) Moonrise 10:53AMMoonset 11:06PM Illumination 31% Phase: Waxing Crescent; Moon at 6 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- 200 Pm Pst Mon Jan 18 2021
.small craft advisory in effect until 9 pm pst this evening...
.gale warning in effect from 9 pm pst this evening through Tuesday afternoon...
Rest of today..N winds 10 to 15 kt with gusts up to 30 kt.
Tonight..N winds 25 to 35 kt with gusts up to 50 kt.
Tue..NE winds 20 to 30 kt with gusts up to 45 kt.
Tue night..NE winds 10 to 20 kt with gusts up to 30 kt.
Wed..S winds up to 10 kt.
Wed night..NW winds up to 10 kt.
Thu..W winds up to 10 kt.
Fri..NW winds 5 to 10 kt. A chance of rain.
PZZ500 200 Pm Pst Mon Jan 18 2021
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Northerly winds will continue to increase over the waters into tonight with occasional low end gale-force gusts possible. Winds will pick up substantially tonight as a burst of strong offshore winds over land spills over into the waters. Widespread gale force conditions will then persist through tomorrow morning over the entire coastal waters including the san francisco and Monterey bays. This will result in widespread hazardous conditions. A large, very long period northwest swell will continue to impact the waters into this evening bringing additional hazards. The next long period northwest swell will arrive mid-week.


7 Day Forecast for Marine Location Near San Mateo, CA
   Hourly   EDIT   Help
location: 37.59, -122.31     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS66 KMTR 182353 AFDMTR

Area Forecast Discussion National Weather Service San Francisco Bay Area 353 PM PST Mon Jan 18 2021

SYNOPSIS. Warm, dry weather today, along with gusty offshore winds in the hills of the San Francisco Bay Area. A strong, and much more widespread, offshore wind event is forecast from this evening through Tuesday morning. During this time, damaging winds are possible in the hills and locally in the valleys and near the coast. Winds will gradually diminish on Tuesday afternoon. A cooling trend is forecast from Wednesday through Friday and slight rain chances develop by the end of the week.

DISCUSSION. as of 01:50 PM PST Monday . Short term weather impacts for the Bay Area and Central Coast still remain the same-damaging winds, fire weather concerns, record warmth, and dangerous surf.

Afternoon satellite shows clear skies across the Bay Area and Central Coast this afternoon. The clear skies are thanks for a strong offshore flow and very dry airmass. The offshore pressure gradient may have weakened slightly since last night, but it still remain high leading to gusty NE to N winds. Winds are strongest over the highest terrain with gusts still 40-60 mph. Gusty winds are mixing to lower elevations with gusts 25-35 mph. A Wind Advisory remains in effect for most of the Bay Area this afternoon through Tuesday afternoon. A second, and stronger burst, of offshore winds are still expected to develop later this evening and overnight. The second round of wind is in response to an upper level low forming over NV and deepening and tracking SW overnight. The upper low eventually becomes cut-off at 500mb off the SoCal. As this happens the offshore gradient (SFO-WMC) is forecast to tighten anywhere from -15 to -19 mb tonight and early Tuesday. Given the forecast areas above 1,000 feet will go to a High Wind Warning (except interior San Benito) at 4 PM today. Would not be surprised to see a few high peaks hit 80 mph again. Given the obs from last night it is totally conceivable that a high peak may get close to 90-100 mph tonight. Needless to say that damaging winds are projected with more trees and powerlines coming down again tonight and Tuesday.

The gusty offshore winds will also lead to above normal temperatures and very low humidity both day and night today through Tuesday. A few records have already occurred this afternoon and the peak heating of the day isn't over yet. Did an update to increase today's and Tuesday's high temperatures. Windy conditions and low RH will contribute to Fire Weather Concerns see below for more details .

Winds will begin to diminish region-wide during the day on Tuesday, yet remain locally strong and gusty into Tuesday night across the North and East Bay.

The shortwave trough responsible for the second burst of offshore winds will quickly exit out of SoCal between Wednesday and Thursday and mid-level heights will quickly fall all across California as another shortwave develops and enters the region during the second half the week. The key difference between this upcoming shortwave and the one currently pivoting the CWA is its position as it will be approaching from the PAC and therefore help introduce more of a maritime air mass into California. As it approaches the CWA, will see a wind shift to more onshore NW flow that will promote greater moisture transport all along the divergent quadrant of the shortwave. As such, GFS and ECMWF are both hinting at an increased possibility for some showers to roll in to Northern and Central California by Friday and into part of the upcoming weekend. This shift in the synoptic trend is consistent with the long-range outlook for the PNA, which is progged to be negative through the remainder of the month and into February. Should this play out, are seeing the possibility for this winter season to redeem itself. Stay tuned.

AVIATION. as of 3:52 PM PST Monday . For the 00Z TAFs. Clear skies across the Bay Area and the Central Coast. VFR is expected through the entire TAF period at all terminals. The main hazard for terminals to be aware of is the increasing offshore flow, which will result in strong wind gusts and LLWS. Observations have eased slightly for current gusts from 20 to 25 kts, but winds are expected to strengthen through the evening and into Tuesday morning. Models consistently showing winds between 1,000 o 1,500 ft between 40-50 kts, with instances exceeding 50 kts. Therefore, LLWS of about 35-45 kt remain in the TAFs at most terminals. Those winds are expected to mix down to the surface providing stronger gusts between 30 to 40 kt, with locally higher gusts possible. Strong wind gusts are expected to continue into Tuesday, but gradually diminish late Tuesday morning and into Tuesday afternoon.

Vicinity of KSFO . VFR. Currently breezy northerly winds. Offshore winds aloft will increase over the next couple of hours for concerns of LLWS in the TAFs through the night. These strong winds are expected to mix down to the surface providing strong wind gusts between 40 to 50 mph, potentially higher, possible. An Airport Weather Warning has been issued, valid 06z through 17z Tuesday morning when the winds are forecast to be their strongest. Winds are not expected to gradually diminish until late Tuesday morning and into the afternoon.

SFO Bridge Approach . Similar to KSFO.

Monterey Bay Terminals . VFR. Winds are breezy at the moment as strongest winds are still located at and north of San Jose, but are slowly moving toward the Central Coast. Northerly winds will increase through the night, increasing the chances for LLWS and stronger wind gusts to mix down to the surface overnight. Winds are expected to gradually weaken late Tuesday morning as skies remain clear.

BEACHES. as of 02:04 PM PST Monday . A large, very long period northwest swell has arrived to the coastal waters, creating hazardous conditions along the coast through the day today. Large swell heights are expected with breaking waves of 18 to 22 feet, locally higher at favored breakpoints, along west to northwest facing beaches. As a result, a High Surf Advisory is in effect through this afternoon for west and northwest facing beaches while a Beach Hazard Statement is in effect for the northern Monterey Bay including Santa Cruz. With warm temperatures present over a holiday weekend, continuous vigilance is advised. Never turn your back to the ocean.

CLIMATE. Record Type: Highs (Old Record Temp/Year)

Jan 18th

Santa Rosa 74/1976 Kentfield 70/2014 Napa 76/1920 Richmond 71/2018 Livermore 74/1919 San Francisco 70/1920 SFO 68/1948 Redwood City 74/2009 Half Moon Bay 72/2009 Oakland Downtown 73/2014 San Jose 74/1920 Gilroy 80/2014* Santa Cruz 83/1920 Salinas Airport 81/1994 King City 83/2009

*Monthly Records

FIRE WEATHER. as of 12:30 PM PST Monday . First and foremost, the Fire Weather Watch was upgraded to a Red Flag Warning earlier this morning. An updated fire weather forecast was also sent out to highlight the Red Flag Warning. Otherwise, forecast remains on track. A very dry airmass continues to settle over the district with impressive RH readings - a few sensors are showing humidity readings in the teens and upper single digits. Additionally, the very gusty offshore flow continues with gusts 40-65 mph. Needless to say, the combination of winds and low RH would normally heighten fire weather concerns. Fortunately, early season rains and some "green up" has tempered a widespread fire weather threat. However, Monterey/San Benito counties received much less rainfall and elevations above 1,000 feet will be at critical levels. That is why a Red Flag Warning has been issued for the Central Coast. Winds may ease a tad on Tuesday, but low RH will remain keeping the fire weather threat through the afternoon on Tuesday. Conditions will continue to improve on Wednesday. A storm system will bring cooler temperatures and possibly some precip by next weekend.

MARINE. as of 02:00 PM PST Monday . Northerly winds will continue to increase over the waters into tonight with occasional low end gale-force gusts possible. Winds will pick up substantially tonight as a burst of strong offshore winds over land spills over into the waters. Widespread gale force conditions will then persist through tomorrow morning over the entire coastal waters including the San Francisco and Monterey Bays. This will result in widespread hazardous conditions. A large, very long period northwest swell will continue to impact the waters into this evening bringing additional hazards. The next long period northwest swell will arrive mid-week.

MTR WATCHES/WARNINGS/ADVISORIES. Tngt. Red Flag Warning . CAZ517-518 Wind Advisory . CAZ518-528-530 High Surf Advisory . CAZ006-505-509-530 High Wind Warning . CAZ507-511-512-517 Wind Advisory . CAZ507-511-512 Wind Advisory . CAZ006-505-506-508>510-513-529 SCA . Mry Bay until 9 PM SCA . Pt Arena to Pt Reyes 0-10 nm until 9 PM SCA . Pigeon Pt to Pt Pinos 0-10 nm until 9 PM SCA . Pt Pinos to Pt Piedras Blancas 0-10 nm until 9 PM SCA . Pigeon Pt to Pt Piedras Blancas 10-60 nm until 9 PM GLW . Mry Bay from 9 PM GLW . Pigeon Pt to Pt Pinos 0-10 nm from 9 PM GLW . Pt Pinos to Pt Piedras Blancas 0-10 nm from 9 PM GLW . Pt Arena to Pt Reyes 0-10 nm from 9 PM GLW . Pigeon Pt to Pt Piedras Blancas 10-60 nm from 9 PM SCA . Pt Arena to Pigeon Pt 10-60 nm until 3 AM GLW . Pt Arena to Pigeon Pt 10-60 nm from 3 AM SCA . Pt Reyes to Pigeon Pt 0-10 nm until 6 PM GLW . Pt Reyes to Pigeon Pt 0-10 nm from 6 PM SCA . SF Bay until 5 PM GLW . SF Bay from 5 PM



PUBLIC FORECAST: MM/Diaz AVIATION: DK MARINE: AS FIRE WEATHER: MM

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 8 mi56 min NW 6 G 8 70°F 57°F1013.1 hPa
AAMC1 - 9414750 - Alameda, CA 13 mi56 min N 8.9 G 15 75°F 54°F1012.6 hPa
LNDC1 14 mi56 min N 12 G 18 76°F 1012.3 hPa
OKXC1 - 9414776 - Oakland (Berth 34), CA 15 mi56 min NNE 18 G 20 70°F 1012.6 hPa
PXOC1 - 9414311 - San Francisco (Pier 1), CA 15 mi56 min NNW 8 G 9.9 64°F 1011.7 hPa
OBXC1 15 mi56 min 73°F 24°F
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 15 mi56 min N 15 G 19
PXSC1 15 mi56 min 64°F 47°F
FTPC1 - 9414290 - San Francisco, CA 17 mi56 min NNE 8.9 G 9.9 68°F 54°F1013 hPa
46237 - San Francisco Bar, CA (142) 22 mi44 min 53°F9 ft
TIBC1 - Tiburon Pier, San Francisco Bay, CA 22 mi63 min WNW 5.1 67°F 1013 hPa
PPXC1 - 9414847 - Richmond (Point Potrero), CA 22 mi56 min N 13 G 18 76°F 1013.2 hPa
RCMC1 - 9414863 - Richmond, CA 24 mi62 min N 15 G 18 74°F 54°F1012.5 hPa
46026 - SAN FRANCISCO - 18NM West of San Francisco, CA 30 mi34 min NW 16 G 18 53°F1013.2 hPa
DPXC1 - 9415141 - Davis Point, San Pablo Bay, CA 32 mi56 min N 14 G 19 74°F 1012.6 hPa
MZXC1 - 9415102 - Martinez-Amorco CA 32 mi56 min N 13 G 18 74°F 53°F1013.1 hPa
UPBC1 33 mi56 min N 12 G 15
CQUC1 33 mi55 min 53°F
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 34 mi34 min N 12 G 16 57°F 1013 hPa50°F
PCOC1 - 9415144 - Port Chicago, CA 35 mi56 min N 11 G 13 71°F 53°F1012.8 hPa
PSBC1 - 9415115 - Pittsburg (Suisun Bay), CA 38 mi56 min N 18 G 24 70°F 1012.7 hPa
SFXC1 - San Francisco Bay Reserve, CA 45 mi89 min NE 16 75°F 1013 hPa16°F
46269 48 mi44 min 58°F 55°F6 ft

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
NW4
--
W3
W4
W1
E2
SW2
SE3
NW2
W1
W1
SE1
SW2
S2
S3
S7
E3
SW2
NE1
NE7
G11
W2
NW6
G9
W7
NW6
1 day
ago
NW5
NW3
NW4
N3
W1
E1
S2
E1
--
W5
S4
SW3
W3
W2
SW3
SW4
NW1
W5
NW1
NW1
NW2
SW2
N3
N6
2 days
ago
N5
W4
W3
G7
S1
SE1
SE3
NW4
NW4
W3
S3
SE2
SE2
SW2
W1
--
E1
NW2
W1
N4
N2
N3
N4
NW4
G7
NW9
G12

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Francisco, San Francisco International Airport, CA3 mi18 minN 810.00 miA Few Clouds67°F39°F36%1012.4 hPa
San Carlos Airport, CA5 mi76 minNW 410.00 miClear75°F21°F13%1012.5 hPa
Oakland, Metro Oakland International Airport, CA9 mi21 minNNW 710.00 miA Few Clouds77°F16°F10%1012.6 hPa
Hayward, Hayward Air Terminal, CA11 mi20 minN 810.00 miFair74°F15°F10%1013.2 hPa
Half Moon Bay Airport, CA11 mi19 minNW 13 G 187.00 miFair64°F37°F37%1012.5 hPa
Palo Alto Airport, CA13 mi87 minN 1410.00 miClear73°F27°F17%1011.8 hPa
Mountain View, Moffett Field, CA18 mi19 minN 15 G 2210.00 miFair72°F14°F11%1012.2 hPa

Link to 5 minute data for KSFO

Wind History from SFO (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 24hrNW12NW6W3NW3W9W5E3W3NW5W6CalmW3S3NW4S8W3CalmCalmNE4N11N16N12N13N8
1 day agoNW15NW12NW12W8SW3CalmCalmCalmCalmCalmCalmSW4S3NE3CalmS3S5SE4N3E3CalmSE3NW4NW8
2 days agoN3CalmCalmE3CalmN8CalmCalmCalmNW4CalmCalmCalmCalmCalmCalmE3NE5CalmE3NW9NW12NW17W14

Tide / Current Tables for Coyote Point Marina, San Francisco Bay, California
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Coyote Point Marina
Click for Map
Mon -- 04:20 AM PST     6.76 feet High Tide
Mon -- 07:21 AM PST     Sunrise
Mon -- 10:16 AM PST     2.53 feet Low Tide
Mon -- 10:52 AM PST     Moonrise
Mon -- 03:47 PM PST     5.98 feet High Tide
Mon -- 05:18 PM PST     Sunset
Mon -- 10:09 PM PST     0.97 feet Low Tide
Mon -- 11:06 PM PST     Moonset
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
2.33.75.16.26.76.65.94.93.932.62.73.44.35.25.865.54.63.42.21.411.2

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
Mon -- 01:52 AM PST     1.50 knots Max Flood
Mon -- 05:28 AM PST     -0.00 knots Slack
Mon -- 07:21 AM PST     Sunrise
Mon -- 08:17 AM PST     -0.98 knots Max Ebb
Mon -- 10:52 AM PST     Moonrise
Mon -- 11:36 AM PST     0.00 knots Slack
Mon -- 02:00 PM PST     0.94 knots Max Flood
Mon -- 05:07 PM PST     -0.00 knots Slack
Mon -- 05:18 PM PST     Sunset
Mon -- 08:23 PM PST     -1.20 knots Max Ebb
Mon -- 11:06 PM PST     Moonset
Mon -- 11:44 PM PST     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
0.81.41.51.310.3-0.3-0.8-1-0.9-0.7-0.30.20.80.90.80.60.1-0.4-0.9-1.2-1.1-0.8-0.4

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




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.