Gale Warning 668, NWS Anchorage, AK

877 
FZAK61 PAFC 021257
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
357 AM AKST Sat Dec 2 2017

Offshore waters forecast for the Gulf of Alaska West of 144W

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ399-030200-
357 AM AKST Sat Dec 2 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front pushes across the Gulf Sat. A 972 mb North Pacific low moves
to 56N 158W at 963 mb Sun afternoon then shifts across Shelikof 
Strait and the northern Alaska Peninsula Mon morning. The associated 
front sweeps across to the Central Gulf Mon morning.

$$

PKZ351-030200-
Gulf of Alaska Offshore North of 57N and West of 144W-
357 AM AKST Sat Dec 2 2017

...GALE WARNING SUNDAY...

.TODAY...S wind 15 to 25 kt. Seas 8 ft.
.TONIGHT...SE wind 15 to 30 kt. Seas 8 to 11 ft.
.SUN...SE wind 30 to 40 kt. Seas 11 to 17 ft building to 17 to 20
ft in the afternoon. Rain.
.SUN NIGHT...S wind 30 to 45 kt. Seas 17 to 28 ft.
.MON...S wind 30 to 45 kt. Seas 15 to 23 ft.
.TUE THROUGH WED...SE wind 15 to 25 kt. Seas 9 to 15 ft.

$$

PKZ352-030200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
357 AM AKST Sat Dec 2 2017

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...S wind 10 to 25 kt. Seas 7 to 11 ft.
.TONIGHT...S wind 15 to 30 kt becoming SE 25 to 40 kt after
midnight. Seas 9 to 15 ft.
.SUN...S wind 25 to 40 kt. Seas 12 to 19 ft. Rain.
.SUN NIGHT...SW wind 30 to 45 kt. Seas 17 to 27 ft.
.MON...S wind 25 to 40 kt. Seas 15 to 23 ft.
.TUE THROUGH WED...SE wind 10 to 25 kt. Seas 9 to 16 ft.

$$

878 
FZAK61 PAFC 022358
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
258 PM AKST Sat Dec 2 2017

Offshore waters forecast for the Gulf of Alaska West of 144W

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ399-031430-
258 PM AKST Sat Dec 2 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A front in the southwest Gulf moves into the northern Gulf through 
Mon. The associated North Pacific low will move to 54N 159W at 962 mb
by Sun morning then to 56N 156W at 960 mb by Sun afternoon and 
inland by Mon morning. A second North Pacific low will move to 55N 
156W at 997 mb by Mon afternoon.

$$

PKZ351-031430-
Gulf of Alaska Offshore North of 57N and West of 144W-
258 PM AKST Sat Dec 2 2017

...STORM WARNING SUNDAY NIGHT...

.TONIGHT...SE wind 15 to 25 kt. Seas 9 ft.
.SUN...SE wind 30 to 45 kt. Seas 10 to 15 ft building to 17 to 20
ft in the afternoon. Rain.
.SUN NIGHT...S wind 35 to 50 kt. Seas 19 to 33 ft.
.MON...SW wind 30 to 45 kt. Seas 18 to 31 ft.
.MON NIGHT...SE wind 15 to 25 kt. Seas 11 to 18 ft.
.TUE THROUGH WED...SE wind 15 to 25 kt. Seas 9 to 15 ft.
.THU...SE wind 25 kt. Seas 16 to 19 ft.

$$

PKZ352-031430-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
258 PM AKST Sat Dec 2 2017

...STORM WARNING SUNDAY NIGHT...

.TONIGHT...SE wind 15 to 30 kt. Seas 9 to 14 ft.
.SUN...S wind 30 to 45 kt. Seas 13 to 21 ft. Rain.
.SUN NIGHT...SW wind 40 to 55 kt. Seas 20 to 32 ft.
.MON...S wind 25 to 40 kt. Seas 15 to 28 ft.
.MON NIGHT...SE wind 10 to 25 kt. Seas 9 to 17 ft.
.TUE THROUGH WED...SE wind 10 to 25 kt. Seas 8 to 16 ft.
.THU...SE wind 25 kt. Seas 16 to 20 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
437 AM AKST Fri Dec 1 2017

.ANALYSIS AND UPPER LEVELS...
A transient upper level ridge is building over western Alaska this
morning as a low south of the Gulf continues to weaken and pull to
the southeast, with a broad longwave trough extending from the
Alcan border region into the eastern Gulf. This pattern is
promoting fairly benign conditions across most of the southern
mainland as showers continue to taper off over the Gulf, with
areas of low stratus and some patchy fog developing in various
locations from the Copper River Basin to Southwest AK. Meanwhile,
a gale force front extending from a deep Kamchatka low is moving
through the eastern Bering accompanied by widespread rain, and is
just beginning to impact the Kuskokwim Delta coast with mixed
precipitation as it tracks eastward towards the mainland.

&&

.MODEL DISCUSSION...
Models show good agreement into the weekend as the ridge quickly
traverses the mainland from west to east, allowing the front and a
trailing shortwave trough to move through the Cook Inlet region
and the Susitna Valley and bring another shot of precipitation to
Southcentral AK on Saturday. Forecast confidence then begins to
decrease once again by Saturday night as a deep North Pacific low
approaches the Alaska Peninsula from the south. Models have
actually backtracked somewhat on their previous agreement with the
arrival of the 00z suite, with the GFS solution now faster and
much farther north than the other guidance whereas the NAM depicts
an overall weaker system than the others. Despite this, was still
able to utilize the NAM for the low position as it represents a
middle ground approach among the guidance and maintains good
continuity from the previous forecast.

&&

.AVIATION...
PANC...Patchy fog over upper Cook Inlet will keep a threat for
IFR/LIFR conditions at the terminal through late morning. VFR
conditions and light winds will then persist through Friday night
before a front moves into the region Saturday morning and drops
ceilings below 5000 ft. Strong downslope flow is expected to keep
showers away from the terminal, though some may still develop in
the vicinity. Southeast winds will develop off of Turnagain Arm
after 16z as the down inlet pressure gradient weakens.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Today is the break between systems across Southcentral as the next
front will begin to move into the area tonight. There is a lot of
warm air with this system which will switch the precipitation type
to rain across most of the coastal areas. Inland there is still
enough cold air to remain snow especially in the Susitna Valley
where there is a Winter Weather Advisory for Saturday. There is
some uncertainty as to how early the snow will start tomorrow
morning but the 6 AM start time looks reasonable at this time but
may need some adjusting as it gets nearer.
Anchorage and the Matanuska Valley may get a quick snow early
tomorrow morning, but the Southeast winds and associated
downsloping will probably cut it off quickly. However, there is
still a chance that the upper level southerly flow will tilt
enough southwestward to help diminish the low level southeast flow
which could then bring in a few inches to Anchorage. This scenario
looks less likely right now so stuck with the chance of snow for
Saturday for the Anchorage and Palmer-Wasilla areas.
On the western Kenai Peninsula, any snowfall Homer experiences
will quickly change to rain Saturday morning. Kenai is the area
that has a trickier precipitation-type forecast as is it close to
the rain-snow line. At this time, it is looking like Kenai and
Soldotna will remain all snow with the transition to rain being
south of there.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
A front continues to slowly push eastward into the Southwest
coast this morning through Saturday, bringing precipitation across
the region along with some warmer southerly flow. The main
challenge regarding this system is precipitation type along the
coastal regions of the western coast, as the warm air mass nudges
inland. Overall the precipitation type should remain snow over
much of the southwest Mainland. However, the western coast is
expected to start off as snow and change over to rain or a
rain/snow mix as early as late Friday morning for the Kuskokwim
Delta, and Friday afternoon for the Bristol Bay area. By Saturday
morning the lingering showers over the area is expected to
transition back to snow, with the exception of mixed precipitation
continuing through Saturday night south of King Salmon as the
next system approaches from the North Pacific.

Models continue to struggle with the placement and timing details
of this upcoming system, but have started to come into some
agreement with the 06Z model runs. They are honing in on a
deepening low tracking across the Alaska Peninsula Sunday, with a
strong front ahead of it bringing another round of gusty winds and
precipitation to the southwest Mainland on Sunday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Low pressure over the far western Bering pushes a front into the
western coast this morning, with a mix of rain and snow showers
expected in its wake. Gusty winds will continue to shift to the
southwest behind the front and will remain the predominant flow
over much of the Bering through Saturday, as the low anchors
itself over the far western Bering. However, the strong flow
diminishes as the western Bering low fills on Saturday and the
next low begins to track into the Alaska Peninsula from the North
Pacific Saturday night. Snow showers are expected to prevail over
the western half of the Bering and Aleutians through Sunday as the
western Bering low slowly weakens and continues to feed in colder
air from the west. Whereas the eastern half of the Bering and
Aleutians will start off as rain with the current system over
them. Precipitation will slowly transition to a rain/snow mix
(from northwest to southeast) overnight tonight, then start
transitioning to mostly snow by Sunday morning as the colder air
from the west begins to push further eastward over the area.

&&

.LONG TERM FORECAST (Saturday through Wednesday)...
Sunday will see the exit of a weak system from Southcentral
Alaska. On it's heels is another storm system that most of the
models have really locked in on. A strong 170+ kt jet across the
northern Pacific will eject a rather potent shortwave about 500
miles South of Dutch. This storm system will be the primary focus
through the end of the weekend and into the early week. This low
will quickly deepen and track to the north, crossing the western
periphery of Kodiak Island. Guidance has been consistent with
bringing a strong front across the the Pacific and into the Gulf
of Alaska. As the front moves across the coast it will bring quite
the river of moisture and warmth with it. Guidance is also
hinting at the fact that Turnagain Arm and high elevations will
see a strong wind event into Monday. It's looking to not be an
event impacting much of the Anchorage Bowl, as winds exiting the
Arm should turn and head south down the inlet. With the strong
front will come strong cross barrier flow over much of
Southcentral. The winds will warm and dry the lower
atmosphere...leading to warmer than freezing temperatures and the
lack of precipitation across much of the usual downslope regions.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 145
MARINE...Gale Warning 155 165 170 172 173 175 176 177 178 180 181
					  411 413 414

&&

SYNOPSIS AND MODEL DISCUSSION...CB
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...SS