Wednesday, March29, 2017 L-36.com


Marine Weather and Tides
SeaTac, WA

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 6:49AMSunset 7:37PM Wednesday March 29, 2017 7:42 PM PDT (02:42 UTC) Moonrise 7:05AMMoonset 8:49PM Illumination 7% 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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PZZ135 Puget Sound And Hood Canal- 300 Pm Pdt Wed Mar 29 2017
.gale warning in effect until 6 pm pdt this evening...
.small craft advisory in effect from 6 pm pdt this evening through late tonight...
Rest of today..SW wind 25 to 35 kt. Wind waves 4 to 6 ft. Showers.
Tonight..SW wind 15 to 25 kt. Wind waves 2 to 4 ft. A chance of showers.
Thu..SW wind 10 to 20 kt becoming 5 to 15 kt in the afternoon. Wind waves 1 to 3 ft. A chance of showers.
Thu night..N wind 5 to 15 kt becoming se after midnight. Wind waves 2 ft or less.
Fri..S wind to 10 kt. Wind waves 1 ft or less.
Fri night..SW wind 5 to 15 kt becoming S 15 to 25 kt after midnight. Wind waves 2 ft or less building to 2 to 4 ft.
Sat..SW wind 10 to 20 kt becoming S 5 to 15 kt in the afternoon. Wind waves 1 to 3 ft.
Sat night..Variable wind to 10 kt becoming N after midnight. Wind waves 1 ft or less.
Sun..Variable wind to 10 kt. Wind waves 1 ft or less.
Mon..Light wind becoming sw to 10 kt. Wind waves 1 ft or less.
PZZ100 300 Pm Pdt Wed Mar 29 2017
Synopsis for the northern and central washington coastal and inland waters..Strong onshore flow behind a cold front will persist into the evening. Moderate onshore flow will continue Thursday. A ridge of high pres will give lighter winds Friday. Another front will arrive Saturday.

7 Day Forecast for Marine Location Near SeaTac, WA
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location: 47.42, -122.28     debug


Area Discussion for - Seattle, WA
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Fxus66 ksew 292225
afdsew
area forecast discussion
national weather service seattle wa
330 pm pdt Wed mar 29 2017

Synopsis Onshore flow with showers and breezy conditions will
gradually decrease tonight. An upper trough will bring a chance of
showers and a possible puget sound convergence zone to prone areas
tonight into Thursday. Parts of western washington should get at
least some sunbreaks by Thursday afternoon as the trough shifts
east. High pressure will build across the area for dry and somewhat
milder weather Friday. A weak system should bring some light rain to
the area over the weekend, with a chance of showers early next week.

Short term Radar and obs indicate showers across much of WRN wa
this afternoon and also breezy to locally windy conditions. The
strongest southerly winds are currently over central/north puget
sound up to admiralty inlet as expected due to lee side meso low
northeast of the olympics. The pdx-bli gradient peaked at near +8 mb
a couple hours ago so winds have likely peaked with just some gusts
to maybe 35 mph over the next hour or two. There is a pretty good
westerly push of wind down the strait and localized areas along the
easterly strait and west side of whidbey island could get a quick
burst of gusty winds to 35 or 40 mph until around sunset. There
looks to be a SW to NE oriented convergence zone band trying to
develop from the kitsap to skagit/snohomish counties. Most meso
models were showing a period of convergence zone activity over
snohomish county this evening which could drop into north king
county later tonight. The nam-12 even brings this precip band into
central/south king county before dissipating late tonight/early
Thursday morning.

The main 500 mb trough axis is now shown by models to move through
much quicker than previous solutions were showing, perhaps shifting
east of the cascades after midnight tonight. This could shut off
residual showers quicker on Thursday as higher pressure aloft beings
to build in from the west, albeit slowly. Shower coverage was
reduced a bit and pops bumped down for most areas although a
residual convergence zone could produce lingering showers in king
county Thursday morning. Most areas will see afternoon sunbreaks or
even clearing toward the west.

High pressure still looks to dominate the pacific northwest Thursday
night and Friday with dry weather and milder temperatures. Forecast
highs were pushed up several degrees above a blend of MOS guidance,
mostly upper 50s across greater puget sound and the southwest
interior. It would not be surprising to see some low 60s around the
area if we get a full day of Sun with light flow.

The gfs/ecwmf both bring a weak trough and decaying frontal band
across the area Sunday. Mostly warm advection occurs ahead of the
system but eventually some onshore flow and clouds develop in the
afternoon. This may hinder high temperatures from reaching 60, but
most MOS guidance shows Saturday being the warmer day so we could
still crack 60 in some spots. There will be a chance of a few
showers but amounts look quite light and spotty.

Long term The gfs/ecmwf solutions are a bit closer together today
and show a fairly typical spring like pattern Sunday through the
middle of next week. A trough will brush the area Sunday with a
chance of light rain or showers. Again, this will not be a big rain
producer but should bring some cooler temperatures and clouds. There
is a good chance for a break in the rain sometime Sunday night
through Monday night but there is still enough uncertainty on timing
of any brief ridging to keep some chance pops in the forecast.

Another system arrives around Tuesday and Wednesday. Neither of
these systems look very wet or cold, just typical systems this time
of year with some clouds, light spotty rain, and near average
temperatures. Mercer

Aviation Southwesterly flow aloft this evening will become
northwesterly late tonight as an upper level trough passes, then
northerly on Thursday. At the surface, strong onshore flow behind a
front will ease tonight but remain moderate on Thursday. The air
mass is moist and slightly unstable with scattered showers.

Most ceilings and visibilities are MVFR this afternoon, though there
are still some ifr ceilings in showers and there are also some clear
patches. Slow improvement should continue into the evening, then
late tonight conditions will likely fall back to low end MVFR.

Ksea... Discussion above applies. Southwest wind 15g25 kt will ease
tonight. Chb

Marine Strong onshore flow behind a front will ease to moderate
tonight. A brief southerly gale in puget sound will end this
evening. Westerly gales in the strait will fall to small craft
advisory level winds by 06z. Onshore flow will persist on Thursday,
with small craft advisory strength winds over most waters. Gradients
will weaken Thursday night, and a ridge of high pres will give
lighter winds on Friday. Another front will arrive Saturday. Chb

Hydrology The heaviest rainfall has passed with just showers or
periods of light rain in post-frontal onshore flow through tonight.

The south and west facing slopes of the olympics received the most
rainfall, up to 5 inches, and up to 2 or 3 inches in parts of the
cascades, mainly central portions in king/snohomish counties. Rivers
will run high or near bankfull in some basins, mainly those running
off the olympics. The bogachiel appears to have crested below flood
stage and will gradually come down tonight.

The skokomish river near potlach surpassed flood stage last evening
and crested this morning. It should slowly fall through tonight,
then probably drop below flood stage by Thursday morning. Only minor
flooding is occurring and should remain limited. Forecasts should
continue to be monitored closely, and always refer to the current
flood statement for the most current information.

Otherwise, flooding is not expected on area rivers during the next 7
days.

Significant rainfall since Tuesday increased the threat of
landslides across WRN wa the past 24 hours. However, additional rain
tonight will not be as heavy, generally a quarter inch or less.

While the saturated soil across WRN wa will maintain an elevated
threat of landslides over the next several days, the highest risk is
passing as precipitation decreases overnight. Will issue one more
special weather statement addressing the last round of rainfall and
indicate a lower but continued threat as a somewhat less active
pattern develops.

Sew watches/warnings/advisories
Wa... None.

Pz... Small craft advisory until 5 pm pdt Thursday for admiralty inlet-
coastal waters from CAPE flattery to james island 10 to 60
nm-coastal waters from CAPE flattery to james island out 10
nm-coastal waters from james island to point grenville 10
to 60 nm-coastal waters from james island to point
grenville out 10 nm-coastal waters from point grenville to
cape shoalwater 10 to 60 nm-coastal waters from point
grenville to CAPE shoalwater out 10 nm-northern inland
waters including the san juan islands-west entrance u.S.

Waters strait of juan de fuca.

Small craft advisory for rough bar until 11 am pdt Thursday for
grays harbor bar.

Gale warning until 11 pm pdt this evening for central u.S.

Waters strait of juan de fuca-east entrance u.S. Waters
strait of juan de fuca.

Small craft advisory until 5 am pdt Thursday for puget sound and
hood canal.

Gale warning until 6 pm pdt this evening for puget sound and
hood canal.



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
TCMW1 - 9446482 - Tacoma Met, WA 12 mi48 min WSW 15 G 21
TCNW1 - 9446484 - Tacoma, WA 13 mi48 min 51°F 47°F1014.9 hPa
WPOW1 - West Point, WA 19 mi102 min SSW 25 G 27 51°F 1011.7 hPa (+1.9)44°F
46121 26 mi40 min 49°F 1014 hPa42°F

Wind History for Tacoma MET, WA
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SE6
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SW6
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E3
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G14

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Seattle, Seattle-Tacoma International Airport, WA2 mi49 minSSW 13 G 1910.00 miPartly Cloudy50°F43°F77%1014.5 hPa
Renton, Renton Municipal Airport, WA6 mi49 minS 12 G 2110.00 miFair51°F44°F77%1014.1 hPa
Seattle, Seattle Boeing Field, WA8 mi49 minSW 13 G 2610.00 miPartly Cloudy51°F44°F77%1013.1 hPa
Tacoma, Tacoma Narrows Airport, WA19 mi49 minSSW 11 G 1810.00 miMostly Cloudy48°F43°F83%1014.5 hPa
Tacoma / McChord Air Force Base, WA21 mi1.7 hrsW 1010.00 miOvercast52°F48°F88%1014.3 hPa
Pierce County-Thun Field, WA22 mi47 minSSW 9 G 1410.00 mi50°F44°F82%1014.9 hPa

Wind History from SEA (wind in knots)
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Last 24hrS9S11SE9S8S7SW4SE6SE9E5E9SE5SE7SE9SE10SE8S14
G21
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G24
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G29
SW17
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G28
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1 day agoSW10SW14S13S11S11S8S10S9S9S8S9S9S8S8S10
G18
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G21
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2 days agoS5S9S10S9S12S6S9S10S8S8S9S7S11S9SW11SW10SW12SW13SW16
G21
SW16W7SW10SW7SW11

Tide / Current Tables for Des Moines, Washington
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Des Moines
Click for Map
Wed -- 12:24 AM PDT     2.07 feet Low Tide
Wed -- 06:24 AM PDT     12.24 feet High Tide
Wed -- 06:53 AM PDT     Sunrise
Wed -- 08:05 AM PDT     Moonrise
Wed -- 12:55 PM PDT     0.51 feet Low Tide
Wed -- 07:10 PM PDT     11.58 feet High Tide
Wed -- 07:35 PM PDT     Sunset
Wed -- 09:48 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.22.33.86.18.710.912.11210.78.55.83.11.20.51.43.56.18.810.711.611.29.87.85.6

Tide / Current Tables for Skagit Bay, 1 mile N of Rocky Point, Washington Current
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Skagit Bay
Click for Map
Wed -- 01:18 AM PDT     0.00 knots Slack
Wed -- 04:55 AM PDT     0.85 knots Max Flood
Wed -- 06:36 AM PDT     -0.01 knots Slack
Wed -- 06:53 AM PDT     Sunrise
Wed -- 08:06 AM PDT     Moonrise
Wed -- 11:59 AM PDT     -1.42 knots Max Ebb
Wed -- 01:43 PM PDT     0.00 knots Slack
Wed -- 05:29 PM PDT     1.00 knots Max Flood
Wed -- 07:28 PM PDT     -0.00 knots Slack
Wed -- 07:36 PM PDT     Sunset
Wed -- 09:49 PM PDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1.2-0.30.30.60.80.90.5-0.2-0.5-0.9-1.2-1.4-1.4-0.90.10.50.810.90.4-0.2-0.5-0.8-1

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

GOES Local Image of PacificNorthwest    EDIT
Geos

Wind Forecast for Seattle, WA (22,6,7,8)
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Ground Weather Radar Station Seattle/Tacoma, WA
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weather_mapweather_map weather_map

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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 numerious 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.