Thursday, January24, 2019 L-36.com


Marine Weather and Tides
Kupreanof, AK

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 8:15AMSunset 4:03PM Thursday January 24, 2019 1:24 AM AKST (10:24 UTC) Moonrise 10:26PMMoonset 11:02AM Illumination 87% Phase: Waning Gibbous; Moon at 18 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- 317 Pm Akst Wed Jan 23 2019
Tonight..SE wind 20 kt. Seas 4 ft.
Thu..E wind 20 kt. Gusts to 40 kt. Seas 4 ft, except 8 ft near ocean entrances. Rain.
Thu night..E wind 20 kt. Seas 4 ft, except 6 ft near ocean entrances. Rain late.
Fri..E wind 20 kt. Gusts to 35 kt. Seas 4 ft, except 6 ft near ocean entrances. Rain.
Fri night..E wind 10 kt. Seas 2 ft or less, except 6 ft near ocean entrances. Rain.
Sat..W wind 10 kt. Seas 2 ft or less.
Sun..Light winds. Seas 2 ft or less.
Mon..Light winds. Seas 2 ft or less.


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 232352
afdajk
southeast alaska forecast discussion
national weather service juneau ak
252 pm akst Wed jan 23 2019

Synopsis A weak front will track across the northern panhandle
Wednesday evening. A stronger front will follow through the gulf
Thursday. A storm force front, strongest of the three, will then
push into the gulf Thursday night.

Short term A weak front across the northern gulf has supported
some mixed precipitation over yakutat and some light snow over
haines skagway. The big conundrum today was how quickly southerly
winds would overtake the cold air entrenched in haines skagway all
day. The entire forecast hinges on this one event. Southerly winds
did find their way into lynn canal mid-day, but haines due to a
persistent northwest wind is remaining very cold at 22 f. We have
adjusted temperatures downward to keep the northerly winds going
a little longer and added snow and an inch of accumulation to
cover this. We now keep the rain at bay until around midnight or
so. Realistically, there will be no mix, but a complete changeover
to rain. However, we need to hedge.

Farther south we battled fog all morning, but higher clouds
spreading over the area helped raise very low stratus decks
sufficiently to allow visibility to rise. Between one frontal
passage and the next later Thursday, there may be enough breaks to
allow more patchy fog to develop across the south late tonight
into Thursday morning.

Judging by new solutions and guidance, our wind forecast needed
very little changes. We nudged a little to the GFS Thursday and
then to the GFS nam canadian Thursday night to better define
Thursday's gale force front and added a lot of strength to the
Thursday night system, now a little more scary with storm force
winds late Thursday night Friday morning. We nudged to the namnest
on the inside Thursday night, but our experience with high res
model winds is that they transfer too much momentum to the surface
and overly mix winds in the midst of warm air advection, so we
did not go the full strength of the high res. In reality, we may
be under noting winds in lynn canal, but stronger periods will
become better defined in the future. We will basically have
persistent southerly breezes.

We decided to post a winter storm watch for the south klondike
and haines highways above the towns of skagway and haines
respectively. A lot of whether we elevate to a warning, advisory,
or downgrade to no statement will depend on how much warm air
gets into the chilkat valley with each succeeding system. Somewhat
worrisome is the lack of great confidence in the southerly flow.

Pressure gradients hint at just enough backing of winds to keep
doubts roaming freer than we would like. Luckily the first couple
of systems will be quicker movers and rain and snow amounts will
be limited. But late Thursday night into Friday, we now suggest 5
to 9 inches possible with snow ratios on the lower side of
climatology.

Pop QPF changes were very conservative and minimal. We elevated
categorical pop to haines and klondike highways while we raised
qpf late Thursday night and Friday morning. The NAM also raised
rainfall amounts for the rest of the panhandle in the early Friday
morning time frame to mid- day Friday. But our assessment of 1 to
2 inches for the north and 2 to 4 for the south Friday and
Saturday still hold. Therefore we found no need to change the
special weather statement.

We used elements of the gfs, nam, canadian, and ECMWF for changes
Thursday through Friday morning. Because of disagreements over a
wave late Friday, we left the forecast unchanged beyond Friday
mid-day.

Long term Friday through Tuesday as of 10 pm Monday, the
weekend forecast remains wet with an atmospheric river impacting
the panhandle between Friday and Saturday. While it will be wet
across the panhandle, ensembles continue to point the bulk of the
precipitation at the southern half of the panhandle. Storm total
precipitation ranges between Friday and Saturday afternoon fall
between 2 and 4 inches for the southern panhandle. Strong warm air
advection will accompany this event brining lows well above
freezing for the panhandle this weekend, as high temperatures
push into 40s even over the northern panhandle Friday. Saturday
the system will shift southeast with a north to south drying trend
expected through the day (precipitation will still be heavy
Saturday morning over the southern panhandle).

Seasonable strong high pressure will build behind this system
through Sunday allowing the panhandle to dry. This will also
introduce a chance for foggy conditions over the northern
panhandle Saturday night into Sunday. Then early next week the
next system will push into the gulf, but timing remains
uncertain.

Overall the biggest changes to the forecast were an upward trend
in pop values with 100% values now introduced for portions of
Friday and Saturday. Additionally, temperatures have been trended
upward once again to account for the strong warm air advection on
Friday. Forecast confidence is above average through Sunday and
below average Monday and beyond.

Ajk watches warnings advisories
Public... Winter storm watch from late Thursday night through Friday
afternoon for akz018-019.

Marine... Gale warning for pkz041>043-051-052.

Small craft advisory for pkz012-013-022-031-033-036-053.

Jwa jb
visit us at http:

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LCNA2 - Lincoln Rock, AK 48 mi75 min SE 9.9 G 16 42°F 1026.8 hPa39°F
FFIA2 - Five Finger, AK 50 mi25 min SSE 9.9 G 14 43°F 1026.7 hPa (-0.3)

Wind History for Port Alexander, AK
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Petersburg, AK16 mi29 minN 010.00 miMostly Cloudy37°F36°F96%1029.3 hPa

Wind History from APG (wind in knots)
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Last 24hrSE3CalmCalmCalmCalmCalmCalmCalmCalmCalmNW3NW4SW3CalmCalmCalmCalmW6CalmCalmCalmCalmCalmCalm
1 day ago53N5NE4SE4CalmW4CalmCalmCalmCalmCalmE3SE3SE4SE3CalmCalmW3SE3CalmCalmSE4SE5
2 days agoCalmCalmCalmW3SW3CalmCalmCalmCalmCalmCalmSE54SE76SE7SE8E7
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Tide / Current Tables for Castle Islands, Duncan Canal, Alaska
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Castle Islands
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Thu -- 03:24 AM AKST     17.27 feet High Tide
Thu -- 08:04 AM AKST     Sunrise
Thu -- 09:00 AM AKST     1.09 feet Low Tide
Thu -- 10:01 AM AKST     Moonset
Thu -- 03:23 PM AKST     17.55 feet High Tide
Thu -- 04:05 PM AKST     Sunset
Thu -- 09:26 PM AKST     Moonrise
Thu -- 09:28 PM AKST     -2.28 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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6.811.515.217.116.814.2105.62.31.12.14.88.512.515.717.417.114.4104.90.5-2-20.2

Tide / Current Tables for Wrangell Narrows (off Petersburg), Alaska Current
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Wrangell Narrows (off Petersburg)
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Thu -- 12:38 AM AKST     5.64 knots Max Flood
Thu -- 03:44 AM AKST     -0.00 knots Slack
Thu -- 06:44 AM AKST     -4.66 knots Max Ebb
Thu -- 08:04 AM AKST     Sunrise
Thu -- 09:45 AM AKST     0.01 knots Slack
Thu -- 10:01 AM AKST     Moonset
Thu -- 12:47 PM AKST     4.69 knots Max Flood
Thu -- 03:45 PM AKST     -0.01 knots Slack
Thu -- 04:03 PM AKST     Sunset
Thu -- 07:00 PM AKST     -5.28 knots Max Ebb
Thu -- 09:25 PM AKST     Moonrise
Thu -- 10:11 PM AKST     0.01 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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5.45.64.42-0.7-3-4.4-4.6-3.9-20.73.14.44.73.92-0.7-3.1-4.7-5.3-4.8-3.2-0.52.4

Weather Map and Satellite Images
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GOES Local Image of PacificNorthwest    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for (5,6,7,8)
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Ground Weather Radar Station Biorka Is., AK
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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.