Marine Weather and Tides
9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.
|Sunrise 6:55AM||Sunset 7:02PM||Sunday September 23, 2018 4:52 AM PDT (11:52 UTC)||Moonrise 5:45PM||Moonset 4:25AM||Illumination 98%|
7 Day Forecast for Marine Location Near San Jose, CAHourly EDIT Help
Area Discussion for - San Francisco/Monterey Bay Area, CA  (on/off)  Help NOTE: mouseover dotted underlined text for definition
|Fxus66 kmtr 231032|
area forecast discussion
national weather service san francisco bay area
332 am pdt Sun sep 23 2018
Synopsis An upper level trough moving across far northern
california will likely maintain a cooling trend for inland areas
today. High pressure will begin building inland to our north and
east tonight. This will result in dry offshore winds and fire
weather concerns for the north bay hills from tonight through
Tuesday. Also, expect much warmer conditions by Tuesday and
Wednesday, with temperatures warming well above seasonal
averages. Temperatures will cool late in the week as an upper low
approaches from the west.
Discussion As of 3:30 am pdt Sunday... Water vapor satellite
imagery shows an upper trough beginning to move across the pacific
northwest and far northern california early this morning. Would
typically expect the marine layer to deepen and onshore flow to
increase under such a scenario, but latest observations indicate
this is not happening. In fact, latest fort ord profiler data
shows the marine layer remaining relatively shallow with a depth
of about 1000 feet. Also, onshore pressure gradients have been
trending weaker. In addition, low clouds early this morning are
less extensive compared to 24 hours ago. These factors call into
question previous forecast thinking that the cooling trend would
continue today, especially inland. Based on current trends, the
most likely outcome will be temperatures near persistence in most
areas. And, with less coastal stratus, some coastal areas may
experience slight warming today.
After the upper trough moves off to our east late today, an upper
ridge is forecast to build off the coast of the pacific northwest
and southward along the northern california coast. Also, surface
high pressure will build inland to our north and east by late
tonight, causing winds in the hills to shift from westerly to
north or northeast, especially in the north bay mountains. Locally
gusty offshore winds in the north bay mountains could result in
critical fire weather conditions at higher elevations from tonight
through Tuesday. See fire weather discussion below for details on
the fire weather watch and fire weather concerns.
Building high pressure aloft during the first half of the week and
weak offshore flow will result in a robust warming trend from
Monday through Wednesday. Widespread highs in the 90s are likely
across inland areas by Tuesday and Wednesday. Coastal temperatures
will be more difficult to predict as they will be very dependent
on the strength of offshore flow. Current WRF model indicates
very weak onshore flow will prevail at the surface with light
offshore flow just above. Such a scenario would mean coastal temps
will mostly remain in the 70s to lower 80s. But if offshore flow
is stronger than anticipated, coastal areas could warm well into
the 80s or even a few lower 90s by Tuesday and Wednesday.
The upcoming warm-up will result in uncomfortably warm daytime
conditions across much of our area from Tuesday through Thursday,
but heat risks are expected to remain low to moderate for the most
part due to long autumn nights and cool overnight lows.
A rex block is forecast to develop offshore by midweek as an upper
low begins to undercut the upper high. The models agree that the
low will slowly undercut the ridge and approach the california
coast during the second half of the week. Cooling due to the low's
approach will likely commence as early as Thursday, but only a
slight downturn in temperatures is expected that day. Much more
significant cooling is then anticipated by Friday and Saturday.
Both the ECMWF and GFS generate spotty light precipitation as the
low moves inland by early Saturday. Since this is still 7 days|
out, will hold off on adding any rain chances to the forecast.
The longer range models forecast a second upper low to move
onshore by early october. The 00z ECMWF is particularly
interesting with this second system, forecasting widespread
significant rainfall across our area on october 1st and 2nd.
Aviation As of 10:35 pm pdt Saturday... For 06z tafs. The
marine layer remains at around 1400 ft per the fort ord profiler
while satellite imagery shows stratus along much of the coast. A
strong northerly gradient has eroded some of the stratus, making
for an uncertain overnight forecast in terms of timing of ifr cigs
around the bay area and north bay TAF sites. Any CIGS that do
develop are expected to remain in place through 16z-18z tomorrow.
Generally light winds overnight and tomorrow morning before
onshore winds increase in the afternoon to 10-15 kt.
Vicinity of ksfo...VFR through tonight. Ifr CIGS by around 10z-
11z, although confidence is low on timing. Onshore winds tomorrow
afternoon around 15 kt.
Sfo bridge approach... Same as terminal.
Monterey bay terminals... Lifr CIGS overnight with possible patchy
fog in the early morning.
Fire weather As of 3:00 am pdt Sunday... Fire weather watch
remains in effect for the north bay mountains from 11 pm Sunday
night through Tuesday afternoon. North to northeast winds will
develop over napa county tonight and drive humidity lower during
the pre-dawn hours of Monday. This offshore wind event looks
moderate, especially in terms of wind strength, but confidence is
pretty high on offshore pattern developing. Fuels remain
critically dry, so any new starts will be susceptible to the
winds, low humidities and dry fuels. Biggest threat area looks to
be napa county hills, northeast sonoma county and around mt tam.
Winds will ease during the day Monday as temperatures warm up
Offshore winds then look to redevelop of similar magnitude Monday
night into Tuesday morning, but with an even drier air mass then
moving in. Overnight humidity recoveries could then well be
confined to around 20 percent or even less. Temperatures are
forecast to continue climbing and widespread 90s are likely across
inland areas Tuesday and Wednesday. But winds are expected to be
light after Tuesday. Cooling is forecast late in the week.
Marine As of 08:15 pm pdt Saturday... Northwest winds will
gradually increase across the coastal waters through tomorrow. The
strongest winds are expected north of point reyes. Winds will
begin to subside into the start of the work week and remain
relatively light through the forecast period. Mixed swell will
continue as well, with a shorter period moderate height northwest
swell and a weak, longer period southerly swell.
Mtr watches warnings advisories
Tday Sca... Pigeon pt to pt pinos 0-10 nm from 9 am
sca... Pt arena to pigeon pt 10-60 nm
sca... Pigeon pt to pt piedras blancas 10-60 nm
sca... Pt pinos to pt piedras blancas 0-10 nm from 9 am
sca... Pt arena to pt reyes 0-10 nm
sca... Mry bay from 2 pm
public forecast: dykema
fire weather: dykema blier rww
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Weather Reporting StationsEDIT (on/off)  Help NOTE: Click on distance to see the station location on a map
|Stations||Dist||Age||Wind||Air Temp||Water Temp||Waves||Pressure||DewPt|
|RTYC1 - 9414523 - Redwood City, CA||29 mi||34 min||56°F||70°F||1012.8 hPa|
|ELXC1 - Elkhorn Slough Reserve, CA||31 mi||67 min||SSW 1.9||51°F||1013 hPa||51°F|
|46092 - MBM1||38 mi||37 min||NNW 1.9||52°F||56°F||1013.3 hPa (-0.3)|
|46240 - Cabrillo Point, Monterey Bay, CA (158)||44 mi||31 min||56°F||2 ft|
|AAMC1 - 9414750 - Alameda, CA||45 mi||40 min||57°F||67°F||1012.4 hPa|
|MEYC1||46 mi||76 min||N 1.9 G 2.9||51°F||59°F||1013.1 hPa|
|LNDC1||46 mi||34 min||58°F||1012 hPa|
|46042 - MONTEREY - 27NM West of Monterey Bay, CA||46 mi||62 min||NNW 9.7 G 12||56°F||55°F||5 ft||1012.2 hPa (-0.5)|
|OMHC1 - 9414769 - Oakland Middle Harbor Met, CA||47 mi||64 min||SSW 1.9 G 5.1|
|46114 - West Monterey Bay, CA||48 mi||22 min||56°F||5 ft|
|OKXC1 - 9414776 - Oakland (Berth 34), CA||48 mi||34 min||57°F||1012 hPa|
|OBXC1||48 mi||34 min||58°F||56°F|
|PXOC1 - 9414311 - San Francisco (Pier 1), CA||49 mi||34 min||57°F||1011 hPa|
Wind History for Redwood City, CA(wind in knots) EDIT (on/off)  Help
Airport ReportsEDIT (on/off)  Help Click EDIT to display multiple airports
|San Jose, San Jose International Airport, CA||11 mi||59 min||N 0||10.00 mi||Fair||56°F||53°F||90%||1012.3 hPa|
|Mountain View, Moffett Field, CA||19 mi||1.9 hrs||N 0||10.00 mi||Fair||57°F||53°F||87%||1013 hPa|
|Watsonville, Watsonville Municipal Airport, CA||22 mi||59 min||N 0||1.75 mi||Fog/Mist||52°F||52°F||100%||1013 hPa|
Wind History from RHV (wind in knots)
|1 day ago||Calm||Calm||Calm||Calm||Calm||Calm||NW||NW||NW||NW||NW||NW||NW||NW||Calm|
|2 days ago||Calm||Calm||Calm||Calm||Calm||Calm||NW||NW||NW||NW||NW||NW||W|
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GOES Local Image of CentralWestCoast EDIT
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Wind Forecast for San Francisco/Monterey Bay Area, CA (7,2,3,4)(on/off)  Help
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