Thursday, March30, 2017

Marine Weather and Tides
South Lake Tahoe, CA

Version 3.4
What's New / NOTES
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 6:44AMSunset 7:23PM Thursday March 30, 2017 5:29 PM PDT (00:29 UTC) Moonrise 7:45AMMoonset 9:38PM Illumination 13% Phase: Waxing Crescent; Moon at 3 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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7 Day Forecast for Marine Location Near South Lake Tahoe, CA
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location: 38.91, -120.01     debug

Area Discussion for - Reno, NV
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Fxus65 krev 302152
area forecast discussion
national weather service reno nv
252 pm pdt Thu mar 30 2017

A strong cold front brought snow showers and high winds to the
region Thursday. Weather should quiet down with warming temperatures
through the weekend. Gusty winds and light rain are possible Sunday
night with a passing storm. Potential exists for a stronger pacific
storm late next week, but impacts and flood potential remain low
confidence this far out.

Short term (through Sunday night)
Spring in the great basin can be quite variable and we definitely
saw a remnant of winter today. Strong cold front brought a classic
snow squall scenario around the morning commute but fortunately road
temperatures were warm enough to melt much of it, outside of the
mountains where more of an impact was seen. Winds gusted above 50
mph and temperatures dropped 10-15 degrees in less than 20 minutes.

Here are the key points for the coming days...

* winds today - very impressive pressure gradient over nevada.

Hrrr showing pressure drops with low near las vegas over 1- 2
mb/hour! This will prompt a resurgence of strong sustained winds
across our region through early evening, with highest risk of
damaging winds in areas south of hwy 50 including hawthorne,
mammoth, owens valley.

* ridge/lake winds Friday - winds should diminish later this
evening as the low moves eastward but remain somewhat gusty into
Friday. On the sierra ridges, NE winds will remain stronger
Friday with 700mb flow 40-50kts. Rough waters possible on lake
tahoe especially west shore with mixed layer up to about 700mb
by afternoon.

* snow showers this evening - airmass behind the cold front is
moderately unstable resulting in continued snow showers.

Accumulations until sundown will be sporadic and limited to
areas above 6000' due to late march solar energy. Latest hrrr
shows showers persisting over mono-mineral counties this evening
with weak instability aloft, so will note that in forecast.

Could be some localized and quick snow accumulations.

* weekend - should be a pleasant spring weekend for the most part
with gradually warming temperatures each day fri-sun. Sunday has
potential to get warm as low level flow switches from cool NE on
sat to a warmer SW flow sun. Increased lower elevation snowmelt
will result which may yield slight increases in stream, river

* Sunday night "wanna be slider" - simulations have been consistent
showing another front dropping in from the NW Sun night. Has the
look of a slider but the wave isn't as sharp as today's and scoots
off to the east. Main results for our region are typical gusty sw
winds starting late Sun afternoon, and a band of rain or snow
showers near the front Sun night. Right now, system looks warmer
than today's with precip type mainly rain except in mountains, so
travel impacts appear low.


Long term Monday into next weekend...

the system exits quickly on Monday, with a ridge building over
northeast california and western nevada for Monday night into
Wednesday. Afternoon temperatures near average Monday will rise to
well above average by mid-week as the ridge axis moves overhead.

Thursday, the ridge slides east and allows a lead wave with a
large-scale north pacific trough to move into the west. The most
recent ECMWF simulation and last two runs of the GFS indicate a
weak lead wave with only minor precipitation amounts, while
yesterday's ECMWF shows a stronger wave and more direct hit from
an atmospheric river (ar) by Thursday night. Moisture transport
simulations from the GFS ensemble only indicate a moderate
probability of ar conditions near the northern ca coast Thursday
night. With this in mind and the fact that recent ar probabilities
have backed off on probabilities through Thursday, confidence is
wavering for substantial precipitation through Thursday night.

For next Friday and into the following weekend, it is likely that
the ar will finally move into the west coast. Current forecasts
favor the pacific northwest; however, intensity and especially
latitude are still in the realm of lower predictability with the
main question revolving around how far south the moisture and jet
stream drop. Increased chances are not a guarantee, but definitely
worth keeping an eye on as a direct hit from another ar would
again increase flooding concerns in the region. Snyder/tolby

Scattered snow showers will dissipate this evening with the loss
of daytime heating and the exit of the upper low (into southern
nv). Lower clouds and widespread higher terrain obscuration should
begin to break up this evening for most of northeast ca and
western nv, although lower clouds (generally 095-120 msl) along
with occasional light snow showers could remain banked up against
the mono county sierra through most of the night.

Ridging builds in Friday and persists through Saturday forVFR
conditions with light-moderate northerly flow. The flow could
bring turbulence along and west of the sierra crest. Snyder

Rev watches/warnings/advisories
Nv... Wind advisory until 11 pm pdt this evening nvz004-005.

High wind warning until 8 pm pdt this evening nvz001.

Lake wind advisory from 10 am to 6 pm pdt Friday for lake tahoe
in nvz002.

Wind advisory until 8 pm pdt this evening nvz002.

Wind advisory until 8 pm pdt this evening nvz003.

Ca... Wind advisory until 11 pm pdt this evening caz070.

High wind warning until 8 pm pdt this evening caz073.

Lake wind advisory from 10 am to 6 pm pdt Friday for lake tahoe
in caz072.

Wind advisory until 8 pm pdt this evening caz072.

For more information from the national weather service visit...


Weather Reporting Stations
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
South Lake Tahoe, Lake Tahoe Airport, CA1 mi36 minNNE 10 G 2110.00 miA Few Clouds34°F15°F46%1013.1 hPa
Carson City Airport, NV24 mi34 minN 16 G 2310.00 miMostly Cloudy41°F19°F42%1015.2 hPa

Wind History from TVL (wind in knots)
Last 24hrCalm3SW5S5S5SW5SE9S9
1 day ago3CalmW34SW4S3S3S4CalmSW4S3CalmCalmS4CalmS3NE3NE5NE5NE9NE7NE7SW7S9
2 days agoN5N5CalmE4CalmCalmCalmSW3S3S3S3S3S4CalmS5CalmS4Calm--33N83NE6

Tide / Current Tables for Sacramento, Sacramento River, California
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Click for MapNote: These data apply only during low river stages.

Thu -- 04:39 AM PDT     0.28 feet Low Tide
Thu -- 06:53 AM PDT     Sunrise
Thu -- 08:51 AM PDT     Moonrise
Thu -- 09:04 AM PDT     3.16 feet High Tide
Thu -- 05:35 PM PDT     -0.01 feet Low Tide
Thu -- 07:27 PM PDT     Sunset
Thu -- 10:14 PM PDT     2.62 feet High Tide
Thu -- 10:43 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Tide / Current Tables for Sacramento #4, Sacramento River, California
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Sacramento #4
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Thu -- 04:39 AM PDT     0.27 feet Low Tide
Thu -- 06:53 AM PDT     Sunrise
Thu -- 08:51 AM PDT     Moonrise
Thu -- 09:05 AM PDT     3.15 feet High Tide
Thu -- 05:35 PM PDT     -0.01 feet Low Tide
Thu -- 07:28 PM PDT     Sunset
Thu -- 10:14 PM PDT     2.61 feet High Tide
Thu -- 10:43 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

Weather Map and Satellite Images
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Weather Map
IR Satellite Image from GEOS

GOES Local Image of CentralWestCoast    EDIT

Wind Forecast for Reno, NV (20,4,5,8)
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Ground Weather Radar Station Reno, NV
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weather_mapweather_map weather_map

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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.