Sunday, February28, 2021
Privacy Policy
L-36.com

Marine Weather and Tides
Cupertino, CA

Version 3.4
NOTICE
1/26/2021 -- The West Coast Satellite images havd been updated. They now use GEOS-17.
1/1/2021 -- The 7 day forecast are now working well. Thank you NOAA for your support.

Sunrise 6:38AMSunset 6:02PM Sunday February 28, 2021 7:58 PM PST (03:58 UTC) Moonrise 7:52PMMoonset 7:49AM Illumination 94% Phase: Waning Gibbous; Moon at 17 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- 240 Pm Pst Sun Feb 28 2021
This afternoon..NW winds 5 to 15 kt.
Tonight..SW winds 5 to 10 kt.
Mon..N winds around 5 kt.
Mon night..NW winds 5 to 10 kt.
Tue..NW winds around 5 kt.
Tue night..NW winds 5 to 10 kt.
Wed..W winds 5 to 15 kt.
Thu..SW winds 5 to 10 kt.
PZZ500 240 Pm Pst Sun Feb 28 2021
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... North winds have decreased with locally breezy conditions lingering in the outer waters this afternoon. Lighter winds will persist tonight, Monday, and most of Tuesday with locally breezy southerly winds alongshore beginning early Monday. A moderate period northwest swell persists through the early week.


7 Day Forecast for Marine Location Near Cupertino, CA
   Hourly   EDIT   Help
location: 37.31, -122.06     debug


Area Discussion for - San Francisco/Monterey Bay Area, CA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS66 KMTR 282356 AFDMTR

Area Forecast Discussion National Weather Service San Francisco Bay Area 356 PM PST Sun Feb 28 2021

SYNOPSIS. Mild afternoon with light winds and clear skies. Most of the San Francisco Bay Area and Central Coast is forecast to remain relatively mild and dry through much of next week before rain chances potentially return for the first weekend of March.

DISCUSSION. as of 01:41 PM PST Sunday . GOES-WEST Air Mass RGB Composite across the Pacific visually captures subtropical moisture ~25N streaming into the tip of Baja while a trough over the Gulf of Alaska slowly dampens the upper-level ridge centered at ~140W this afternoon. Closer to home, are observing mild temperatures this afternoon with light winds in contrast to the gustier candidness along the foothills and up into the higher peaks earlier this morning. Skies for the most part remain clear with only a handful of high-base clouds across the region.

Another night with widespread mins in the 40s F across the region is expected tonight while some of the interior valleys, particularly in the North Bay, will drop down to the mid to upper 30s F owing to greater air flow blockage. Warmest overnight spots will be concentrated along the Bay Shoreline, where temps in the mid 40s F are expected by dawn tomorrow. Looking at another mild day on Monday with widespread upper 60s F and even some low 70s F across the interior.

The trough over the Gulf of Alaska will eventually track south as the upper-level ridge retrogrades westward between today and Wednesday. It will quickly take on a cut-off low signature as it disassociates from the mid-level zonal flow at ~50N and track south and parallel to the California Coast. While GEFS and Canadian ensemble members have kept the low slightly closer to the shoreline during this portion of its trajectory, EC members, along with SREF guidance, are in greater agreement that the system will stay farther out to sea. Nonetheless, even the closest solutions remain well offshore. This makes synoptic sense given that the departure of the upper-level ridge from the immediate coast will result in a favorable environment for the low to deepen right along the original center of the ridge. Given its nature as a cutoff low, however, its trajectory will inevitably get shifted onto more of an eastward track as it encounters the zonal flow from the subtropical moisture. And while such a setup will translate into some moisture returns for SoCal, the system will be too far to the south of us for any of that moisture to make it up into our neck of the woods.

Given the current outlook, looking at a dry, calm, and mild pattern Tuesday through Thursday, with afternoon highs in the upper 50s F to low-to-mid 60s F along the Coast, mid-to-upper 60s F along the Bay Shoreline, and low 70s F in more favorable interior locations. Nighttime lows will generally drop down into the 40s although, as tends to be the case, the interior valleys will likely drop down into the mid-30s F and we may see some areas of patchy frost as a result. The only locations within our CWA that might see any sprinkles out of this will be down along the extreme southern portions of the Big Sur coast for Tuesday afternoon. That being said, some of that southerly flow (albeit rather dry) associated with the cutoff low will eventually advect across our waters as early as Monday afternoon, which should act as a coolant for the south-facing portions of the Coast all the way through Wednesday.

Turning our attention over to next weekend, day 3-7 clusters pick up on some uncertainties between the EC, Canadian, and GFS ensemble members: namely the timing and amplitude of the next trough that will replace the cutoff low. GEFS members are leaning towards a less amplified trough and a delayed start time to the showers until around late Friday/early Saturday, while EC ensemble members prefer a deeper trough and a faster moisture return that would bring showers into the CWA as early as Friday afternoon. Biggest reason for these uncertainties lies with the amount and timing of upper- level wave momentum transfer that occurs between Siberia to Alaska. A faster-paced transfer would allow for the upper-level ridge that will have retrograded to the northcentral PAC by midweek to continue to build westward towards Japan which in turn would result in the EC ensemble mean solution to play out, while a slower-paced transfer would favor the GEFS mean solution. It should also be noted that the main driver for the available moisture in this setup will be the culmination of the position of the upper-level trough along ~140W and its ability to tap into subtropical moisture to its south. This means the EC mean solution is also the most favorable for higher precip totals. Disagreements will hopefully lessen as we get closer to the event, but for now looking like we have fair agreement with regards to the potential for some rain next weekend starting either Friday afternoon or late Friday evening and going into Saturday.

All in all, this synoptic-scale shift in the oceanic pattern coincides with what would be expected under a negative PNA index as troughing becomes the more dominant synoptic-scale feature across the northeast PAC. EC weeklies continue to trend negative, suggesting a wetter pattern for the West Coast through the first half of March.

AVIATION. as of 03:56 PM PST Sunday . For the 00Z TAFs. VFR across terminals with light N to NE winds. Clear skies observed on satellite. Overnight, continued clear skies and light winds. A bit breezier Monday afternoon with southerly flow developing, and perhaps few high clouds. Vicinity of KSFO . VFR. Light northerly winds backing to the WNW through early evening, then light and variable overnight. Southerly winds develop Monday afternoon. VFR through the taf period. SFO Bridge Approach . Similar to KSFO.

Monterey Bay Terminals . VFR with light to breezy onshore winds. Overnight, light and variable, becoming ESE. Continued VFR through the period.

MARINE. as of 02:40 PM PST Sunday . North winds have decreased with locally breezy conditions lingering in the outer waters this afternoon. Lighter winds will persist tonight, Monday, and most of Tuesday with locally breezy southerly winds alongshore beginning early Monday. A moderate period northwest swell persists through the early week.

MTR WATCHES/WARNINGS/ADVISORIES. Tngt. None.

PUBLIC FORECAST: Diaz AVIATION: Lorber MARINE: Bingaman

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 16 mi58 min NW 5.1 G 6 56°F 59°F1021.9 hPa (+0.6)
46269 26 mi58 min 51°F 52°F4 ft
AAMC1 - 9414750 - Alameda, CA 34 mi58 min WNW 5.1 G 8 58°F 56°F1021.5 hPa (+0.7)
LNDC1 36 mi58 min W 2.9 G 5.1 59°F 1021.1 hPa (+0.5)
OMHC1 - 9414769 - Oakland Middle Harbor Met, CA 37 mi58 min W 5.1 G 7
OBXC1 37 mi58 min 58°F 35°F
PXSC1 38 mi58 min 59°F 29°F
PXOC1 - 9414311 - San Francisco (Pier 1), CA 38 mi58 min WSW 7 G 9.9 59°F 1020.2 hPa (+0.3)
ELXC1 - Elkhorn Slough Reserve, CA 38 mi73 min ENE 2.9 53°F 1021 hPa37°F
MLSC1 - Moss Landing, South Harbor, CA 38 mi28 min 50°F
OKXC1 - 9414776 - Oakland (Berth 34), CA 38 mi58 min W 4.1 G 7 57°F 1021.2 hPa (+0.5)
46092 - MBM1 39 mi61 min W 5.8 51°F 50°F1021.1 hPa
FTPC1 - 9414290 - San Francisco, CA 40 mi58 min WSW 9.9 G 12 55°F 54°F1021.2 hPa (+0.0)
46042 - MONTEREY - 27NM West of Monterey Bay, CA 40 mi38 min NNW 9.7 G 12 51°F 51°F1021.9 hPa48°F
46012 - HALF MOON BAY - 24NM South Southwest of San Francisco, CA 44 mi38 min NW 7.8 G 12 47°F 1022.3 hPa44°F
PPXC1 - 9414847 - Richmond (Point Potrero), CA 44 mi58 min WSW 2.9 G 4.1 58°F 1021.5 hPa (+0.3)
46237 - San Francisco Bar, CA (142) 45 mi58 min 51°F5 ft
46114 - West Monterey Bay, CA 45 mi32 min 51°F6 ft
TIBC1 - Tiburon Pier, San Francisco Bay, CA 45 mi47 min Calm 56°F 1021 hPa
RCMC1 - 9414863 - Richmond, CA 46 mi58 min Calm G 2.9 58°F 52°F1021.2 hPa (+0.3)
46240 - Cabrillo Point, Monterey Bay, CA (158) 48 mi62 min 54°F3 ft

Wind History for Redwood City, CA
(wind in knots)    EDIT      (on/off)   Help
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
6
PM
7
PM
Last
24hr
NW8
NW6
NW1
W3
W4
NW3
S2
G5
W2
W2
S2
W4
NW3
SE3
G6
E3
SE5
N2
N5
NW10
NW8
NW5
NW3
G6
NW8
NW7
NW5
1 day
ago
W16
G23
W17
G23
W10
W7
G10
W11
W6
W8
W4
W3
W5
W6
W5
NW6
NW10
G14
NW11
G14
NW11
G14
NW13
G16
NW13
NW15
W14
G17
NW15
W14
G18
W11
G15
NW8
G11
2 days
ago
N3
NE1
SW2
SW2
--
E2
S2
--
S2
SW1
SW2
S2
SW1
W4
NW4
G7
N5
NW9
NW17
G23
W15
W14
G17
W15
G20
W17
G21
W17
W17
G21

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
San Jose, San Jose International Airport, CA8 mi65 minNNW 910.00 miPartly Cloudy57°F33°F41%1020.9 hPa
Mountain View, Moffett Field, CA8 mi68 minN 510.00 miFair55°F45°F67%1021.3 hPa
Palo Alto Airport, CA12 mi4.2 hrsN 410.00 miClear66°F28°F24%1020.7 hPa
San Jose / Reid / Hillv, CA13 mi71 minNW 410.00 miClear59°F21°F23%1021 hPa
San Carlos Airport, CA18 mi65 minWNW 610.00 miClear59°F27°F29%1021.7 hPa
Hayward, Hayward Air Terminal, CA24 mi64 minN 010.00 miFair56°F39°F53%1022.1 hPa

Link to 5 minute data for KNUQ

Wind History from NUQ (wind in knots)
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
6
PM
7
PM
8
PM
Last 24hrW4W4W4W3Calm3W6CalmW3W5CalmCalmCalmNE5NE9N7N5N65NE3N5N6N5NW4
1 day agoW9W8W6CalmNW4CalmCalmW4CalmCalmW3W353NW9NW8
G15
N10NW9
G14
NW11NW8
G16
NW10W8NW7
G13
W6
G11
2 days agoN6CalmNE3CalmS4CalmCalmCalmCalmCalmCalmCalmCalmCalmN74N9N17NW11
G18
W10
G17
NW8
G19
W11
G20
W11
G18
NW12
G21

Tide / Current Tables for Upper Guadalupe Slough, San Francisco Bay, California
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Upper Guadalupe Slough
Click for Map
Sun -- 01:45 AM PST     9.10 feet High Tide
Sun -- 06:40 AM PST     Sunrise
Sun -- 07:48 AM PST     Moonset
Sun -- 08:01 AM PST     1.72 feet Low Tide
Sun -- 01:15 PM PST     10.18 feet High Tide
Sun -- 06:01 PM PST     Sunset
Sun -- 07:51 PM PST     Moonrise
Sun -- 08:28 PM PST     -0.23 feet Low 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
78.79.18.475.13.42.21.72.54.46.88.910.19.98.874.72.50.8-0.1-01.43.7

Tide / Current Tables for Dumbarton Point 2.3 mi NE, South San Francisco Bay, California Current
   EDIT      (on/off)   Help   One Week of Data
Dumbarton Point 2.3 mi NE
Click for Map
Sun -- 01:47 AM PST     -0.01 knots Slack
Sun -- 05:49 AM PST     -1.09 knots Max Ebb
Sun -- 06:40 AM PST     Sunrise
Sun -- 07:49 AM PST     Moonset
Sun -- 07:52 AM PST     0.00 knots Slack
Sun -- 10:32 AM PST     1.40 knots Max Flood
Sun -- 01:31 PM PST     -0.00 knots Slack
Sun -- 06:01 PM PST     Sunset
Sun -- 06:04 PM PST     -1.45 knots Max Ebb
Sun -- 07:52 PM PST     Moonrise
Sun -- 08:27 PM PST     0.01 knots Slack
Sun -- 11:08 PM PST     1.56 knots Max Flood
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
1.20.6-0.1-0.5-0.8-1-1.1-0.60.10.81.31.410.4-0.2-0.6-1-1.3-1.4-1.1-0.40.51.21.6

Weather Map
       (on/off)   Help Weather Map
wmap_P
GEOS Local Image of CentralWestCoast    EDIT
NOTE: This section has been updated as of 1/26/2021. If the image you are expecting is not showing, please let me know. You may use the EDIT function to update your location.
Link to Loop

Other links: GEOS-West     Contential US     Full GOES-East
Ground Weather Radar Station




Please read website Cookie, Privacy, and Disclamers by clicking HERE.