Sunday, September23, 2018

Marine Weather and Tides
Pacheco, CA

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9/17/2018 XTide broke when 1and1 "upgraded" my server. It has been esculated. I am sorry for the problem.

Sunrise 6:56AMSunset 7:03PM Sunday September 23, 2018 1:12 PM PDT (20:12 UTC) Moonrise 5:47PMMoonset 4:26AM Illumination 99% Phase: Waxing Gibbous; Moon at 14 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
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PZZ530 San Pablo Bay, Suisun Bay, The West Delta And The San Francisco Bay North Of The Bay Bridge- 855 Am Pdt Sun Sep 23 2018
Today..SW winds 5 to 15 kt...becoming 10 to 15 kt with gusts up to 25 kt this afternoon.
Tonight..SW winds 5 to 15 kt.
Mon..SW winds 5 to 15 kt with gusts up to 25 kt.
Mon night..SW winds 5 to 15 kt with gusts up to 25 kt.
Tue..SW winds 5 to 15 kt.
Tue night..SW winds 5 to 15 kt with gusts up to 25 kt.
Wed..W winds up to 10 kt.
Thu..W winds 5 to 15 kt.
PZZ500 855 Am Pdt Sun Sep 23 2018
Synopsis for the central california coast and bays including the Monterey bay..Greater farallones...and cordell bank national marine sanctuaries... Strengthening northwest winds will become more widespread today. Expect locally gusty conditions by the afternoon particularly along the coast north of point reyes and south of point sur as well as in the outer waters. Locally steep fresh swell will be generated by these gusty winds. Winds are forecast to weaken Monday morning and remain relatively lighter through the start of the work week.

7 Day Forecast for Marine Location Near Pacheco, CA
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location: 37.98, -122.07     debug

Area Discussion for - San Francisco/Monterey Bay Area, CA
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Fxus66 kmtr 231813
area forecast discussion
national weather service san francisco bay area
1113 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 10:00 am pdt Sunday... Temperatures this
morning are running a few to as much as 6 degrees cooler compared
to 24 hours ago as a weak mid upper level short-wave trough
impacts northern california. With this and a marine layer around
1,000 feet in depth, patchy fog and low clouds continue along the
coast, across san francisco and into the oakland region, along the
central coast and locally inland. Low clouds and fog should
dissipate late this morning into the afternoon. However, onshore
winds should increase through the afternoon. This should all
translate to a slight cool down for inland areas while coastal
locations may actually be a degree or two warmer with less cloud
cover compared to Saturday. Either way, little change is expected
today aside from the increased onshore flow. For additional
information, please see the previous forecast discussion below.

Prev 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 11:15 am pdt Sunday... Scoured out marine layer
has nearly mixed out from the san francisco bay area and san mateo
coast, with some lingering low clouds throughout the monterey bay
and southward through the big sur coastline.VFR CIGS being
reported across the region with kmry lingering on the edge of the
retreating status deck. Onshore winds increase today bring breezy
to locally gusty conditions near the coast and through coastal
gaps. For tonight, expect a shallower compressed marine layer with
localized impacts from patchy dense fog in the north bay and
around the monterey bay, to some tempo sct bkn ifr level clouds
into mid morning Monday.

Vicinity of ksfo...VFR. Light westerly wind increasing by late
morning with gusts possible up to 20-25 knots in the afternoon and
evening. Low clouds will struggle tonight but may briefly see some
sct develop north of terminal around sunrise.

Sfo bridge approach... Similar to ksfo.

Monterey bay terminals...VFR today. Early return of low cigs
tonight, with patchy dense fog developing late tonight into early
Monday morning.

Fire weather As of 10:00 am pdt Sunday... The fire weather
watch has been cancelled for the north bay mountains which was
previously in effect from 11 pm tonight through Tuesday afternoon.

However, dry northerly winds remain forecast to develop over this
region, especially over napa county, during this timeframe. This
will drive humidity levels lower through Tuesday afternoon with
overnight recoveries only in the 20-25% range. Afternoon humidity
values may fall into the single digits to lower teens Monday and
Tuesday, yet wind speeds are forecast to remain below red flag

Precautions should still be taken as fuels remain critically dry
and any localized gusty winds in the ridges peaks could result
in an elevated fire weather risk.

Marine As of 11:07 am pdt Sunday... Strengthening northwest
winds will become more widespread today. Expect locally gusty
conditions by the afternoon particularly along the coast north of
point reyes and south of point sur as well as in the outer
waters. Locally steep fresh swell will be generated by these gusty
winds. Winds are forecast to weaken Monday morning and remain
relatively lighter through the start of the work week.

Mtr watches warnings advisories
Tngt Sca... Pigeon pt to pt pinos 0-10 nm until 9 pm
sca... Pt arena to pigeon pt 10-60 nm
sca... Pigeon pt to pt piedras blancas 10-60 nm
sca... Pt arena to pt reyes 0-10 nm until 3 am
sca... Pt pinos to pt piedras blancas 0-10 nm until 3 am
sca... Mry bay until 9 pm
public forecast: gass dykema
aviation: drp
marine: drp
fire weather: gass dykema
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Weather Reporting Stations
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Wind History for Union Pacific Rail Road Bridge (UPRR), CA
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1 day
2 days

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Concord, Buchanan Field, CA1 mi20 minNW 910.00 miFair80°F50°F35%1010.2 hPa
Napa, Napa County Airport, CA19 mi19 minSSW 710.00 miFair71°F54°F55%1011.5 hPa
Oakland, Metro Oakland International Airport, CA21 mi20 minNW 710.00 miA Few Clouds69°F53°F57%1013.1 hPa
Hayward, Hayward Air Terminal, CA22 mi19 minWNW 410.00 miFair73°F53°F50%1013.5 hPa
Livermore, Livermore Municipal Airport, CA23 mi20 minWNW 610.00 miFair83°F48°F30%1011.4 hPa

Wind History from CCR (wind in knots)
Last 24hrNW12NW12NW8N11NW9NW6SW7SW5SW7CalmCalmCalmSE3CalmCalmCalmCalmCalmN3--W4NW5NW8NW9
1 day agoNW11NW11W10W10W6N6N4N4NW4NW3CalmCalmNW4NW7W4W4W3CalmCalmNW6N5N8N4N7
2 days ago5NE6CalmN7NW9N6N3CalmS4CalmSE4S4S3SE3CalmSE5CalmCalm--S4CalmCalmW6NW8

Tide / Current Tables for Suisun Point, Carquinez Strait, California
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Tide / Current data from XTide NOT FOR NAVIGATION
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Tide / Current Tables for Roe Island S, Suisun Bay, California Current
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Tide / Current data from XTide NOT FOR NAVIGATION
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Weather Map and Satellite Images
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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.
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Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for San Francisco/Monterey Bay Area, CA (16,3,4,5)
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Ground Weather Radar Station Sacramento, CA
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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 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 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.