Thursday, April27, 2017 L-36.com


Marine Weather and Tides
Kupreanof, AK

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 5:07AMSunset 8:42PM Thursday April 27, 2017 6:25 PM AKDT (02:25 UTC) Moonrise 6:31AMMoonset 10:15PM Illumination 4% Phase: Waxing Crescent; Moon at 2 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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PKZ035 Sumner Strait- 319 Pm Akdt Thu Apr 27 2017
.small craft advisory through late tonight...
Tonight..SW wind 25 kt diminishing to 15 kt late. Seas 5 ft. Showers in the evening.
Fri..SW wind 15 kt becoming E in the afternoon. Seas 3 ft.
Fri night..E wind 10 kt. Seas 2 ft or less.
Sat..E wind 15 kt. Seas 3 ft. Rain.
Sat night..E wind 15 kt. Seas 3 ft.
Sun..SW wind 10 kt. Seas 3 ft.
Mon..E wind 10 kt. Seas 2 ft or less.
Tue..E wind 15 kt. Seas 3 ft.

7 Day Forecast for Marine Location Near Kupreanof, AK
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location: 56.65, -133.15     debug


Area Discussion for -
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Fxak67 pajk 272226
afdajk
southeast alaska forecast discussion
national weather service juneau ak
226 pm akdt Thu apr 27 2017

Short term /tonight through Saturday/ 1002 mb low spinning 60
miles wnw of sitka is currently bringing wet and breezy conditions
to many areas of the central panhandle as the second wrap of the
associated front moves inland. Gusts around 25 to 30 mph have
been recorded at sitka, angoon, and juneau so far this afternoon.

This low will gradually move inland S of cross sound this evening
and is expected to weaken over the northern panhandle tonight. W
winds of around 15 to 25 kt are present on the S side of the
system and will be hitting the central outer coast for much of the
night. Some of this will bleed over into the northern inner
channels as well. Ended up raising winds for tonight's forecast over
what was previously there using hires NAM with some inner channel
areas seeing up to 25 kt out of the south at times tonight. Winds
are expected to diminish as the system rapidly weakens late
tonight.

Showers continue through Fri night, particularly over the northern
panhandle, as onshore flow in the wake of the low persists. A
building ridge will gradually shut those showers off, but it will
only be when offshore flow develops ahead of the next low on sat
that the showers shut off completely. The weekend is looking
rather dry for the north with persistent offshore flow. Meanwhile
the southern panhandle will be dealing with increasing clouds,
wind, and precip as a 996 mb low moves NE toward haida gwaii.

Long term /Saturday to Thursday/ ridging over the eastern gulf
and panhandle expected to shift into british columbia as an upper
level trough/closed low moves into the southeastern gulf. 500 mb
vort MAX band associated with this trough may lift northward late
Saturday as ridging builds again over the central gulf and then
into the eastern gulf through Sunday. Upstream a large deep upper
low moves over the aleutians and remains quasi stationary through
mid week with the ridge remaining over the eastern gulf and
panhandle. By the end of the week this broad upper low will
likely shift east but uncertain on the exact track.

At the surface on Saturday there is be a weak low in the northwest
gulf with a developing low tracking south of the eastern gulf.

Lots of model spread on the track of this system, and with the
position of this low track differences will result in large
forecast variation. Best estimate is the low will move near haida
gwaii through Saturday and likely dissipate by early Sunday
morning. Seems to be a trend of models moving the low center
further south which will have more offshore flow for the northern
regions, thus drier weather, compared to the south which will
have greater chance for rain. Nudged winds from this system
toward small craft levels in the southeast gulf. Gfs/canadian have
trended further north with stronger winds than the ecmwf/nam
which also dissipate the low sooner. Decided best option was a
compromise blend until we get better model resolution. Beyond the
weekend models fell more in line with the next surface low near
the aleutians the the associated occluded front moving into the
gulf Monday into Tuesday. Later in the week a much stronger low
appears to track up from the southwest and will have more impact
with respect to winds/pop/qpf.

Once again the word of the long range is uncertainty, especially
for the weekend. Rmop values below 30% with the weekend low.

Values improve later in the week as the next systems move in and
model align. Used a blend of gfs/ecmwf for Saturday even though
they were not in great agreement. Did this to get a smoother wind
field and moderate any very low or high wind speeds. For the rest
of the long range utilized wpc for its use of ensembles. Forecast
confidence is below average.

Aviation Mainly MVFR conditions with low moving onshore across
the central area this evening. This will continue for most central
and south TAF sites into early Fri morning. Should improve toVFR
during late Fri morning to early afternoon. For paya, trapped low
level moisture will keep MVFR conditions going through the night
with potential for ifr late tonight as trof moves in. They may
improve toVFR Fri afternoon but for now keeping MVFR ceilings as
that will depend on how much of a break in cloud cover occurs to
allow heating to raise cloud bases.

Ajk watches/warnings/advisories
Public... None.

Marine... Gale warning for pkz042.

Small craft advisory for pkz022-031>036-041-043.

Small craft advisory due to seas for pkz051.

Eal/prb
visit us at http://

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LCNA2 - Lincoln Rock, AK 48 mi76 min E 2.9 G 4.1 45°F 1017.8 hPa41°F
FFIA2 - Five Finger, AK 50 mi86 min SSE 23 G 31 43°F 1015.7 hPa (+2.4)
CDEA2 - Cape Decision, AK 69 mi64 min WSW 20 G 29

Wind History for Port Alexander, AK
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Petersburg, AK16 mi30 minS 57.00 miLight Rain44°F39°F85%1017.8 hPa

Wind History from APG (wind in knots)
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Last 24hr3CalmCalmCalmSW5
G15
S6S9SW84E335S3CalmE5E6SE66SE75NE3Calm6S5
1 day agoE4SE6SE3E5CalmCalmSE3SE4W3Calm4CalmW3CalmCalmE3E3E3NE5CalmE8E4CalmNE3
2 days agoCalmW4CalmCalmCalmCalmCalmW3CalmSW3S3E3E3NE3E5E5E7NE65E3E6E7CalmE5

Tide / Current Tables for Castle Islands, Duncan Canal, Alaska
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Castle Islands
Click for Map
Thu -- 02:11 AM AKDT     18.42 feet High Tide
Thu -- 05:14 AM AKDT     Sunrise
Thu -- 06:31 AM AKDT     Moonrise
Thu -- 08:17 AM AKDT     -3.68 feet Low Tide
Thu -- 02:51 PM AKDT     16.76 feet High Tide
Thu -- 08:26 PM AKDT     -0.13 feet Low Tide
Thu -- 08:27 PM AKDT     Sunset
Thu -- 10:14 PM AKDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
13.516.918.417.514.293.3-1.3-3.5-3.1-0.348.813.115.916.715.111.46.72.50.10.22.56.3

Tide / Current Tables for Grief Island, Duncan Canal, Alaska
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Grief Island
Click for Map
Thu -- 01:59 AM AKDT     18.55 feet High Tide
Thu -- 05:14 AM AKDT     Sunrise
Thu -- 06:31 AM AKDT     Moonrise
Thu -- 08:17 AM AKDT     -3.78 feet Low Tide
Thu -- 02:39 PM AKDT     16.84 feet High Tide
Thu -- 08:24 PM AKDT     -0.25 feet Low Tide
Thu -- 08:26 PM AKDT     Sunset
Thu -- 10:13 PM AKDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
14.217.418.517.313.68.42.9-1.5-3.7-3.1-0.14.49.413.716.316.714.610.86.12.1-00.22.76.8

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 (22,6,7,8)
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Ground Weather Radar Station Biorka Is., AK
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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.