Storm Warning 38, NWS Juneau, AK

048 
FZAK67 PAJK 212325
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
400 PM AKDT WED SEP 21 2016 

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT THE AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WINDWAVE AND SWELL HEIGHT.

PKZ398-221400-
400 PM AKDT WED SEP 21 2016 
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A STORM FORCE FRONT WILL MOVE INTO THE EASTERN GULF WEDNESDAY
NIGHT AND THEN THROUGH THE PANHANDLE ON THURSDAY. SW WINDS WILL
SPREAD ACROSS THE GULF BEHIND THE FRONT ON THURSDAY INTO
THURSDAY NIGHT. 

$$

PKZ310-221400-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
400 PM AKDT WED SEP 21 2016 

...STORM WARNING TONIGHT...

.TONIGHT...S WIND 50 KT BECOMING W 20 KT LATE. SEAS BUILDING TO
22 FT. RAIN...HEAVY AT TIMES.
.THU...SW WIND 20 KT. SEAS 20 FT SUBSIDING TO 15 FT IN THE
AFTERNOON. S SWELL. RAIN...HEAVY AT TIMES IN THE MORNING. SLIGHT
CHANCE OF THUNDERSTORMS. 
.THU NIGHT...W WIND 20 KT. SEAS 12 FT. S SWELL. SLIGHT CHANCE OF
THUNDERSTORMS. 
.FRI...SW WIND 20 KT. SEAS 10 FT. S SWELL. SLIGHT CHANCE OF
THUNDERSTORMS. 
.FRI NIGHT...SW WIND 20 KT. SEAS 9 FT. S SWELL SHIFTING TO THE W
LATE. SLIGHT CHANCE OF THUNDERSTORMS. 
.SAT...SW WIND 20 KT. SEAS 8 FT. 
.SUN...SE WIND 15 KT. SEAS 7 FT. 
.MON...NW WIND 20 KT. SEAS 6 FT. 

$$

343 
FZAK67 PAJK 221147
OFFAJK

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE JUNEAU AK
347 AM AKDT THU SEP 22 2016

OFFSHORE WATERS FORECAST FOR GULF OF ALASKA EAST OF 144W

WIND FORECASTS REFLECT THE PREDOMINANT SPEED AND DIRECTION
EXPECTED. SEA FORECASTS REPRESENT THE AVERAGE OF THE HIGHEST
ONE-THIRD OF THE COMBINED WINDWAVE AND SWELL HEIGHT.

PKZ398-230600-
347 AM AKDT THU SEP 22 2016
.SYNOPSIS FOR THE EASTERN GULF OF ALASKA...
A STORM FORCE FRONT OVER THE EASTERN GULF WILL MOVE INTO THE
PANHANDLE TODAY.  

$$

PKZ310-230600-
GULF OF ALASKA NORTH OF 55 DEGREES NORTH AND EAST OF 144 DEGREES
WEST-
347 AM AKDT THU SEP 22 2016

...GALE WARNING TODAY...

.TODAY...W WIND 40 KT BECOMING SW 20 KT. SEAS 21 FT SUBSIDING TO
14 FT IN THE AFTERNOON. RAIN EARLY IN THE MORNING...THEN SLIGHT
CHANCE OF THUNDERSTORMS. 
.TONIGHT...W WIND 15 KT. SEAS 11 FT. S SWELL. SLIGHT CHANCE OF
THUNDERSTORMS. 
.FRI...SW WIND 20 KT. SEAS 10 FT. S SWELL. SLIGHT CHANCE OF
THUNDERSTORMS. 
.FRI NIGHT...S WIND 20 KT. SEAS 9 FT. SW SWELL. SLIGHT CHANCE OF
THUNDERSTORMS. 
.SAT...W WIND 15 KT. SEAS 8 FT. 
.SUN...S WIND 15 KT. SEAS 7 FT. 
.MON...NW WIND 20 KT. SEAS 8 FT. 

$$

Southeast Alaska Forecast Discussion...UPDATED
National Weather Service Juneau AK
1021 PM AKDT TUE SEP 20 2016

.UPDATE...Fog formed just before sunset in Ketchikan. Obs have
been verified by webcams. The surface axis of the ridge should be
positioned right over the southern Inner Channels, therefore, we
moved up onset of fog to the early evening. We also added a note
about visibility in Clarence Strait.

We made bigger updates in the mid-range. New High Res Guidance
through 18Z Thursday along with NAM indicated 925 mb low level
jets across the Inside Channels on Thursday caused enough concern
to amend the forecast for periods three through four--Wednesday
night and Thursday. NAM wind speeds at 925 mb across the central
Panhandle reach 55 kt around mid-day. High res NMM and ARW suggest
storm force winds through Stephens Passage at the surface. While
we are not going that high, we must respect this with a bump to
gales across the central Inner Channels. Even though the
atmosphere as a whole is stable, the low levels (below 850 mb)
suggest some measure of instability--enough to transfer much of
the energy from the low level jet all the way to the surface. In
addition, the relatively fast progression of the front through the
Panhandle is also a factor in increasing winds as the front's
forward momentum will add magnitude to surface winds. We have
raised wind speeds through much of the marine passages in the
central Panhandle by 10-15 kt to gale force with probably the
greatest change reserved for Stephens Passage and Southern Lynn
Canal. No real changes needed in frontal passage timing. Pelican,
Gustavus, Hoonah, Juneau, Sitka, and Angoon should receive the
strongest winds Thursday morning. Kake, Petersburg, Craig,
Klawock, Coffman Cove, Wrangell, Hydaburg, Ketchikan, and
Metlakatla should receive the strongest winds from midday into the
afternoon.

&&

SHORT TERM...Extensive very low level marine layer was a long
time in clearing out today with a dense fog advisory that lasted
into the afternoon for southern portions of the panhandle. As the
high pressure ridge shifts east over the panhandle, another night
of light winds is expected. Mostly clear skies tonight will be
favorable for radiation fog to form once again, with the thickest
fog over the inner channels and immediate coastal areas. Areas
that saw significant sunshine today will be less likely to see
dense fog again tonight due to surface drying. Another limiting
factor for another night of dense fog will be encroaching cloud
cover from the approaching front. A cirrus shield has already
spread over the northern two thirds of the panhandle with thicker
mid level clouds now moving into Yakutat from the west. For
tomorrow, variable cloudiness across southeast Alaska - ranging
from overcast in the north to mostly clear over the south - once
the fog dissipates. Tomorrow also represents one last day of dry
weather for areas south of Cape Fairweather. Rain will have moved
into the Yakutat area by late tonight and become heavy at times by
tomorrow afternoon.

Winds over the eastern gulf will steadily increase through
tomorrow afternoon - southerly or southeasterly - except for an
easterly storm force barrier jet west of Icy Cape by late morning
tomorrow. Strong wind gusts to 40 mph also expected in Yakutat by
tomorrow afternoon. At that time, gales will extend down to Cape
Edgecumbe with small craft winds down to the Dixon Entrance. Also
will have small craft easterlies out of Cross Sound and the
western half of Icy Strait. Conditions will continue to
deteriorate into the extended range forecast period.

No changes to pressure, winds, or temps today. Updated PoP and QPF
with the latest high resolution models. Overall forecast
confidence is average.

LONG TERM.../Wednesday night through Tuesday/ Wet and windy
weather continues into the start of the long range for the gulf
and northern gulf coast, and will start to spread to the rest of
the panhandle through Thu. Highest winds and seas are expected
Wed night and early Thu with storm force winds and seas of 20
plus feet for a large portion of the NE gulf. Some of these winds
will impact the Yakutat area though the highest winds should stay
offshore due to barrier jet effects. However, I am still
expecting gusts to reach 50 mph late Wed night. The wind max is
due to a weak wave riding north along the front wed night. Mid
range models are still playing around with track as current
guidance has trended a little faster and farther west compared to
24 hours ago sending it to Cape Suckling now rather then Cape
Yakataga. Otherwise the rest of the gulf will still experience
gale force winds for most of Wed night.

Into Thu, the westerly flow on the south side of the wave will
push the front rapidly through the panhandle. Southerly winds will
be increasing late Wed night across the inner channels with the
highest winds expected early Thu morning. low level jet strength
along the front is expected to be around 55 to 65 kt at 850 mb.
So Gusts to 45 to 55 mph will likely be common along the outer
coast with gusts to 40 or 50 mph in many inner channel areas as
the front moves through. Winds will diminish throughout the Thu
afternoon and evening.

Heavy rain will also be a concern as there is still plenty of
sub-tropical moisture for the front to work with. Yakutat will
bare the brunt of it as the wave working north along the front
will briefly stall it over the northern gulf coast. Total
rainfall amounts will likely be in the 3 to 4 inch range before
the rain changes to showers on Thu. Farther east, the main
panhandle will see rain as well but the forward speed of the front
will have increased to the point that the heaviest rain will not
stick over a certain area for an extended period of time.
Expecting around a total of 1 inch to 1.5 inches at the highest in
these area before the rain diminishes Thu afternoon through Thu
evening.

The rest of the extended period is rather quiet comparatively
speaking. Upper level trough over the Bering Sea and western
Alaska will keep SW onshore flow and showers going through early
next week. Overall forecast remains damp through next week.
Several shortwave are embedded in this flow that could enhance
rainfall but long range models are still trying to figure out
when and where for each. Current models are starting to reach a
consensus on a wave aiming for the southern panhandle Sun but
timing is questionable. Used mainly WPC for long range updates.

AVIATION...Low CIGS and reduced VSBY will be an issue once again
tomorrow morning, but conditions are expected to improve earlier
than what was experienced today. Low level turbulence and wind
shear will only be a concern tomorrow afternoon west of Cape
Fairweather.

AJK Watches/Warnings/Advisories...
PUBLIC...STRONG WIND from Wednesday afternoon through Thursday morning
     for AKZ017.
MARINE...Storm Warning for PKZ052.
     Gale Warning for PKZ042-043-051-053.
     Small Craft Advisory for PKZ021-022-041.

Fritsch/EAL

&&

.AJK Watches/Warnings/Advisories...
PUBLIC...STRONG WIND from Wednesday afternoon through Thursday morning
     for AKZ017.
MARINE...Storm Warning for PKZ052.
     Gale Warning for PKZ042-043-051-053.
     Small Craft Advisory for PKZ021-022-041.
&&

99/99

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