Monday, January22, 2018 L-36.com


Marine Weather and Tides
Coffman Cove, 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 8:17AMSunset 4:01PM Monday January 22, 2018 3:26 AM AKST (12:26 UTC) Moonrise 11:23AMMoonset 11:44PM Illumination 32% Phase: Waxing Crescent; Moon at 6 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- 323 Pm Akst Sun Jan 21 2018
.small craft advisory tonight through Monday...
Tonight..E wind 15 kt increasing to 25 kt late. Out of interior passes, gusts to 35 kt late. Seas building to 5 ft. Rain and snow showers late.
Mon..E wind 25 kt. Gusts to 40 kt. Seas 5 ft. Rain and snow showers.
Mon night..SE wind 25 kt. Gusts to 40 kt. Seas 5 ft.
Tue..E wind 25 kt. Gusts to 40 kt. Seas 5 ft.
Tue night..NE wind 30 kt. Gusts to 45 kt. Seas 6 ft. Snow and rain showers.
Wed..E wind 25 kt. Seas 5 ft.
Thu..E wind 20 kt. Seas 4 ft.
Fri..E wind 25 kt. Seas 5 ft.

7 Day Forecast for Marine Location Near Coffman Cove, AK
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location: 56.02, -132.92     debug


Area Discussion for -
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Fxak67 pajk 212357 cca
afdajk
southeast alaska forecast discussion... Corrected
national weather service juneau ak
257 pm akst Sun jan 21 2018

Short term Our focus continues to be on widespread snow showers
and accumulations on Monday but attention was also given to
another system bringing more showers along the coast and for the
south going into Tuesday.

Our stable longwave pattern with two ridges, one over the bering
and another over western canada, and a deeply amplified trough
extending south from mainland alaska well into the gulf of alaska
has been and will be dictating our weather for some time. Cold
air from the bering regions of alaska long-ago dove south to round
the base of the trough and currently rests in the outer gulf
poised to enter through our southern reaches on Monday. With
plenty of lift due to steep lapse rates close to 8c km and
positive vorticity advection, we should see potentially intense
showers spread across southeast following an occluded front on
Monday. Showers will begin in the far south late Sunday night and
through Monday spreading north across the rest of our cwa.

Temperatures will remain marginal for snow in the south and along
the eastern and southeast coast, and with some building
thicknesses tonight ahead of the main low- level trough, we feel
increasingly confident that some areas in the far south may only
see rain showers tonight. However, as the front lifts north,
colder air will rush in to support a mix, even as temperatures
will remain in the middle to upper 30s. North of petersburg and
inland of sitka temperatures should support all snow.

In the north and interior panhandle we have concerns on snow
accumulations and potential impacts. We have raised snow amounts
to ranges just shy of advisory, perhaps 1 to 4 inches Monday. With
more southerly flow in the low to mid levels than easterly,
orographic lifting will be enhanced in many areas including
juneau. Steep lapse rates will migrate inland as well. Given the
convective nature of the snow, we do foresee some areas
experiencing some higher snowfall accumulations and potential
short-term white-outs. But this polar, more marine, air mass,
should also result in a wetter snow, one that compacts a little
more easily. Thus, we have kept ratios around 10:1. And in
addition, to all this, the southerly gradient behind the front has
tended to eat well- prepared higher snow forecasts for lunch. So
the rain-snow line could potentially make its way farther north
than forecast. The band of enhanced precipitation looks to be
around 6 hours, but we may see a bit longer duration of 9 hours
for juneau, which is one reason we felt confident enough to raise
amounts, but somewhat concerned as not enough.

Looking farther in time for Tuesday, the wave lifting Monday's
system stalls moisture across the northern panhandle and the
eastern gulf. A more southern originating wave lifts northward to
contribute to more snow shower enhancement with some rain mixed
in along the immediate coast. Models are mainly holding back
precipitation expanse for the central interior and northern inner
channels, in part due to increasing outflow, so impacts may be
most felt along the coast and the south. But we do look for more
light snow accumulations for portions of the western and southern
interior communities.

Outflow strong winds are still afflicting lynn canal and cross
sound with 30 kt and gusts to 40 mph in skagway. These are
forecast to steadily decline through tonight with some enhanced
southerlies appearing in the far south around daybreak Monday
morning. These southerlies will lift northward following the
frontal passage. But there remains some uncertainty as to weather
they reach lynn canal and skagway. Currently, we are skeptical and
have held back. Leading into Tuesday, a new low develops well to
our south that changes the gradient quite rapidly back to
northerly and increases through the time period. Thus, we have
stronger outflow winds redeveloping into Tuesday.

We relied on ECMWF and NAM for any updates to pop qpf, but the gfs
and ECMWF with some wind edits later on Tuesday. Forecast
confidence is good for snow in the north central regions tomorrow
with a mix to the south. However, while we give general ranges for
amounts, mother nature will likely gift us a few surprises in
snow accumulations for a few locations Monday evening.

Long term Tuesday through Sunday ... Long range period begins
with a large upper level low dominating the gulf of alaska and
another located over the northern interior. Upstream, a building
upper ridge will be situated over the bering sea. The gulf low
exhibits a slight positive tilt, but becomes negatively tilted by
Wednesday morning as the northern interior low drops south. By
Thursday, the original low shifts east to hecate strait and
weakens as the northern interior low moves south into the
northwest gulf and deepens. By this time. The upstream ridge will
have strengthened into an omega block, with another upper low near
hokkaido and sakhalin island. By the end of next weekend, the
omega block remains strong and in place and a large upper low once
again dominates the gulf of alaska.

The combined effect of the upper low(s) over the gulf and the
building upper ridge to the west will be to advect in colder low
level air over the panhandle. Some modification of this airmass
will occur as it crosses a considerable distance over the open
ocean, but the ridge will prevent any warmer air from the west
from mixing in. 850h temperatures marginally supportive of
snowfall on Tuesday and then again from Thursday onward. Similar
story for 1000-500 thicknesses. 1000-850 thicknesses remain
marginal to favorable for the entire week. Daytime highs over the
southern half of the panhandle from frederick sound south
indicating that there is a good chance that at least some of the
precipitation for this coming week will be in the form of rain.

Otherwise, what precip we do see may be mostly in the form of
snow. No well defined fronts currently being depicted in medium to
long range models, so convective precip (showers) is anticipated
through at least Tuesday night. 24 hour snow totals at this time
indicating possibly advisory level snowfall at most. Major caveat
there is that a snowfall forecast for 3-5 days into the future in
a convective environment in southeast alaska is a stretch at best,
so keeping track of how this forecast changes is in everybody's
best interest.

No significant changes to pressure or winds. Pop and QPF from gfs
and the canadian nh with some help from ECMWF through Thursday
night and the latest wpc thereafter. Daytime highs and overnight
lows generally adjusted down slightly for the second half of the
week based on current model spectrum plots. Overall forecast
confidence is average, but below average for snow totals.

Ajk watches warnings advisories
Public... Strong wind until 9 pm akst this evening for akz018.

Marine... Gale warning for pkz012.

Small craft advisory for pkz013-022-031-033-035-036-041>043-051-
052.

Jwa fritsch
visit us at http:

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LCNA2 - Lincoln Rock, AK 12 mi76 min ESE 8 G 15 37°F 999.8 hPa37°F
KECA2 - 9450460 - Ketchikan, AK 84 mi44 min ESE 7 G 11 39°F 43°F1002.1 hPa

Wind History for Ketchikan, AK
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Klawock - Klawock Airport, AK33 mi33 minNE 410.00 miLight Rain36°F35°F97%1000.5 hPa

Wind History from AKW (wind in knots)
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Last 24hrCalmNE6NE103NE8NE5CalmE5NE8NE4NE3N4NE5NE4NE6NE4CalmNE5CalmCalm--CalmNE4NE4
1 day agoNE5NE7NE8NE7N9
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2 days agoNE7NE5NE6NE8NE6NE7NE8NE7NE65NE5NE7NE6NE3NE3NE4CalmCalmNE53E5NE6NE7NE7

Tide / Current Tables for Lake Bay, Alaska
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Lake Bay
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Mon -- 04:02 AM AKST     15.18 feet High Tide
Mon -- 08:03 AM AKST     Sunrise
Mon -- 09:49 AM AKST     3.42 feet Low Tide
Mon -- 10:22 AM AKST     Moonrise
Mon -- 03:54 PM AKST     14.54 feet High Tide
Mon -- 04:03 PM AKST     Sunset
Mon -- 09:59 PM AKST     1.28 feet Low Tide
Mon -- 10:44 PM AKST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
5.5912.114.415.214.412.19643.44.46.69.41213.914.513.611.17.84.52.11.32.1

Tide / Current Tables for Exchange Cove, Alaska
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Exchange Cove
Click for Map
Mon -- 04:01 AM AKST     14.28 feet High Tide
Mon -- 08:04 AM AKST     Sunrise
Mon -- 09:52 AM AKST     3.42 feet Low Tide
Mon -- 10:23 AM AKST     Moonrise
Mon -- 03:53 PM AKST     13.64 feet High Tide
Mon -- 04:03 PM AKST     Sunset
Mon -- 10:02 PM AKST     1.28 feet Low Tide
Mon -- 10:44 PM AKST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
5.28.411.413.514.313.511.58.75.943.44.36.38.811.313.113.612.710.57.44.42.21.32

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 (7,2,3,4)
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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.