Sunday, August20, 2017 L-36.com


Marine Weather and Tides
Chenega, AK

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
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.

Sunrise 6:22AMSunset 9:42PM Sunday August 20, 2017 12:51 PM AKDT (20:51 UTC) Moonrise 3:49AMMoonset 8:11PM Illumination 2% Phase: Waning Crescent; Moon at 28 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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PKZ129 Passage Canal- 810 Am Akdt Sun Aug 20 2017
Today..E wind 10 kt in the morning becoming variable less than 10 kt. Seas 2 ft. Rain.
Tonight..Variable wind less than 10 kt becoming W 10 kt after midnight. Seas 2 ft. Rain.
Mon..W wind 10 kt in the morning becoming variable less than 10 kt. Seas 2 ft. Widespread rain showers.
Mon night..Variable wind less than 10 kt. Seas 2 ft.
Tue..W wind 10 kt. Seas 2 ft.
Wed through Thu..E wind 10 kt. Seas 2 ft.

7 Day Forecast for Marine Location Near Chenega, AK
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location: 60.33, -148.15     debug


Area Discussion for -
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Fxak68 pafc 201159
afdafc
southcentral and southwest alaska forecast discussion
national weather service anchorage ak
359 am akdt Sun aug 20 2017

Analysis and upper levels
An upper level low embedded within the arctic trough over the
alaska mainland continues to drop south along west coast of
alaska. Water vapor imagery this morning depicts a weak shortwave
rotating along the western periphery of the upper level trough but
looks as if it will not phase with the upper level trough and will
be ejected into the north pacific. Rain showers have developed
over southwest alaska in response to the upper level low but an
infusion of colder and drier air is suppressing the overall
coverage and intensity of the showers. Shower activity across
southcentral alaska has been widely scattered with showers across
both coastal and inland locations. Mesoscale precipitation banding
developed over anchorage during the evening on Saturday as convergence
associated with southerly up-inlet flow and southeasterly turnagain
arm winds aided in creating some light to moderate rain bands.

A surface low pressure system has been rapidly developing this
morning southwest of kodiak island. While infrared imagery this
morning looks unimpressive, water vapor imagery shows just how
impressive the upper levels presently look. A very impressive
atmospheric river has begun to set up but it looks like it will
remain south of our forecast area with the alaska panhandle likely
to feel the full force of the atmospheric river in the coming
days.

Model discussion
Models are in overall pretty good agreement this morning. There
are still some timing and placement issues with the developing low
pressure southwest of kodiak island. This will have an impact on
when rainfall will start across southcentral alaska today and
Monday and just how much rain will fall across interior locations.

At this time, coastal locations will likely feel the brunt of the
front associated with this low with upslope flow along the
coastal mountains maximizing precipitation processes. Interior
locations remain a little bit more of a question mark as to how
far inland rain makes it and how much rainfall anchorage, palmer
and other locations will receive. Models had been trending drier
on Friday but now they are showing higher rainfall amounts across
the interior. Elevated instability will be another component that
will be hard to parameterize as it will easily enhance rainfall
over some locations leading to decent mesoscale banding.

Otherwise, models are in good agreement with high pressure
building in the wake of this surface low across the bering sea.

Aviation
Panc... Gusty southeasterly winds will diminish shortly after
sunrise this morning.VFR conditions will prevail through the
morning with MVFR ceilings and vsby likely by noon as rain begins
to fall. Conditions will begin to improve Monday morning.

Short term forecast southcentral alaska (days 1 and 2)
The upper level low over southwest alaska will continue to move
south, entering the southwest gulf tonight. The associated surface
low, which is currently south of kodiak island, will move
northeast and stall just south of the kenai peninsula this
evening. There is plenty of moisture with this low that is moving
into southcentral this morning. Rain will develop over much of the
area today, and continue tonight as the surface low remains
stalled. On Monday the surface low will retreat southward,
as the upper low moves eastward just south of gulf. Conditions
will thus begin to dry out from west to east. By Tuesday morning
the low complex will have exited the area, with just some stray
showers remaining.

Short term forecast southwest alaska (days 1 and 2)
An upper low will track southward over the southwest mainland
today, keeping some showery conditions over the area through early
Monday morning. At this time, a tight pressure gradient will
materialize as the low departs for the gulf of alaska and a ridge
builds in from the west, resulting in gusty winds over bristol
bay through Monday night.

Short term forecast bering sea aleutians (days 1 and 2)
High pressure will continue to build over the bering sea,
resulting in widespread stable conditions over much of the area.

By early this afternoon as the ridge pushes further east, gusty
north to northwesterly flow will build over the eastern
bering aleutians and alaska peninsula. Expect gap winds south of
the alaska peninsula to ramp up tonight and reaching gale force
by Monday morning.

Long term forecast (days 4 through 7)
Beginning the extended period forecast Tuesday night, there will
be a closed upper low over the far southeastern gulf of alaska
with a mobile shortwave trough over the central bering sea. In
between these systems there will be a shortwave ridge axis nosing
into southern alaska with an anchoring trough centered over the
north slope of alaska. This pattern will be the end of a short
quiescent break in the weather. By Wednesday afternoon, the trough
over the bering sea will merge with the anchoring trough over the
north slope with increasing southwest upper level flow ushering in
more clouds and rain to southern alaska. This cloudier and wetter
pattern looks to persist through Friday, although uncertainty
grows by this period as the GFS and ECMWF differ with respect to
the position of the trough and the degree of interior downslope
flow. Coastal locations, especially near the gulf of alaska, will
be wet, but by Thursday and Friday it looks like there is a
possibility that downslope drying dramatically limits interior
precipitation, especially in the ECMWF solution. For now a middle
ground solution will be favored, depicting coastal rain into the
weekend and more showery conditions inland by the end of the week.

Afc watches warnings advisories
Public... None.

Marine... Gale... 119 130 131 150
fire weather... None.

Synopsis and model discussion... Mmc
southcentral alaska... Bl
southwest alaska bering sea aleutians... Tp
long term... Ja


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
46081 - Western Prince William Sound 33 mi62 min NNE 18 G 21 51°F 53°F2 ft1006.2 hPa (-2.0)50°F
46076 - Cape Cleare AK 58 mi62 min S 12 G 12 55°F 57°F4 ft1003.1 hPa (-1.6)53°F
SWLA2 - 9455090- Seward, AK 69 mi52 min 58°F

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Portage, Portage Glacier, AK48 mi59 minESE 8 G 174.00 miRain Fog/Mist51°F46°F86%1005.3 hPa

Wind History from ATO (wind in knots)
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Last 24hrE3E5E5E665SE6444E7E6E44645--SE8SE86E7SE11
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1 day ago6
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4SE7SE7--E8
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553E5E54CalmCalmCalmCalmCalmCalmCalmCalmCalmCalm
2 days agoSE44546--46E6E6E6SE4CalmCalmCalmCalmE4E7E7
G16
E96E946

Tide / Current Tables for Chenega Island, Dangerous Passage, Prince William Sound, Alaska
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Chenega Island
Click for Map
Sun -- 12:26 AM AKDT     13.02 feet High Tide
Sun -- 04:48 AM AKDT     Moonrise
Sun -- 06:18 AM AKDT     Sunrise
Sun -- 07:06 AM AKDT     -1.93 feet Low Tide
Sun -- 01:35 PM AKDT     11.14 feet High Tide
Sun -- 07:14 PM AKDT     1.51 feet Low Tide
Sun -- 09:11 PM AKDT     Moonset
Sun -- 09:31 PM AKDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
12.912.811.48.85.51.9-0.8-1.9-1.20.93.979.510.9119.97.95.22.81.6246.99.8

Tide / Current Tables for Eshamy Bay, Knight Island Passage, Prince William Sound, Alaska
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Eshamy Bay
Click for Map
Sun -- 12:28 AM AKDT     13.52 feet High Tide
Sun -- 04:47 AM AKDT     Moonrise
Sun -- 06:17 AM AKDT     Sunrise
Sun -- 07:04 AM AKDT     -1.93 feet Low Tide
Sun -- 01:37 PM AKDT     11.64 feet High Tide
Sun -- 07:12 PM AKDT     1.51 feet Low Tide
Sun -- 09:10 PM AKDT     Moonset
Sun -- 09:31 PM AKDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
13.413.311.99.25.72-0.8-1.9-1.21.14.27.39.911.411.510.48.25.42.81.52.14.17.110.1

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

GOES Local Image of PacificNorthwest    EDIT
Geos

Wind Forecast for (16,3,4,5)
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Ground Weather Radar Station Middleton 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.