Gale Warning 406, NWS Anchorage, AK

727 
FZAK61 PAFC 161201
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
401 AM AKDT Sat Sep 16 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.

PKZ399-170300-
401 AM AKDT Sat Sep 16 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A front moves into the southwestern Gulf this evening...moves to 
the northern Gulf by Sat morning...then dissipates there by Sat
evening. A 986 mb low near 57N 154W Sat evening moves to 57N 146W
at 990 mb Sun morning...then moves into the eastern Gulf.

$$

PKZ351-170300-
Gulf of Alaska Offshore North of 57N and West of 144W-
401 AM AKDT Sat Sep 16 2017

.TONIGHT...SE wind 10 to 15 kt increasing 15 to 25 kt after 
midnight. Seas 6 ft.
.SAT...SW wind 15 to 25 kt. Seas 6 to 11 ft. Rain.
.SAT NIGHT...SW wind 15 to 25 kt becoming SE 10 to 15 kt after 
midnight. Seas 10 to 15 ft.
.SUN...NE wind up to 15 kt. Seas 10 to 15 ft.
.SUN NIGHT...NW wind 15 kt. Seas 8 to 13 ft.
.MON THROUGH WED...SW wind up to 20 kt. Seas 4 to 9 ft.

$$

PKZ352-170300-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
401 AM AKDT Sat Sep 16 2017

...GALE WARNING SATURDAY AND SATURDAY NIGHT...

.TONIGHT...SE wind 10 to 20 kt becoming SW 15 to 30 kt after midnight.
Seas 5 to 9 ft. Rain.
.SAT...SW wind 20 to 30 kt increasing to 25 to 35 kt in the afternoon.
Seas 7 to 12 ft building to 12 to 21 ft in the afternoon.
.SAT NIGHT...SW wind 25 to 35 kt becoming NW after midnight. E of
147W...SW wind 15 to 25 kt. Seas 14 to 24 ft.
.SUN...NW wind 20 to 35 kt. Seas 14 to 22 ft.
.SUN NIGHT...NW wind 10 to 25 kt. Seas 9 to 16 ft.
.MON THROUGH WED...SW wind up to 15 kt. Seas 4 to 9 ft.

$$

709 
FZAK61 PAFC 162331
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
331 PM AKDT Sat Sep 16 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.

PKZ399-171430-
331 PM AKDT Sat Sep 16 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A strong front will dissipate along the northern Gulf coast this 
evening. A 985 mb low at 58N 159W will move to 55N 143W at 995 mb 
Sun afternoon...then it will weaken as it moves to the eastern 
Gulf through Mon morning.

$$

PKZ351-171430-
Gulf of Alaska Offshore North of 57N and West of 144W-
331 PM AKDT Sat Sep 16 2017

.TONIGHT...SW wind 15 to 25 kt becoming S 10 to 15 kt after midnight.
Seas 9 to 14 ft.
.SUN...E wind 15 kt becoming N in the afternoon. Seas 9 to 15 ft.
.SUN NIGHT...NW wind 15 kt becoming W after midnight. Seas 7 to
12 ft.
.MON...SW wind up to 15 kt. Seas 5 to 9 ft.
.MON NIGHT...W wind 10 to 25 kt. Seas 4 to 7 ft.
.TUE THROUGH THU...W wind 10 to 25 kt. Seas 4 to 7 ft.

$$

PKZ352-171430-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
331 PM AKDT Sat Sep 16 2017

...GALE WARNING THROUGH SUNDAY...

.TONIGHT...SW wind 25 to 35 kt diminishing to 15 to 25 kt after
midnight. W of 148W...SW wind 25 to 35 kt becoming W after midnight. 
Seas 14 to 22 ft.
.SUN...NW wind 25 to 35 kt diminishing to 15 to 25 kt in the 
afternoon. N of 56N...Variable wind 15 kt becoming NW in the 
afternoon. Seas 15 to 21 ft subsiding 12 to 18 ft in the afternoon.
.SUN NIGHT...NW wind 15 to 25 kt. Seas 9 to 16 ft.
.MON...W wind 10 to 20 kt. Seas 7 to 10 ft.
.MON NIGHT...W wind 15 to 30 kt. Seas 6 to 10 ft.
.TUE THROUGH THU...W wind 10 to 25 kt. Seas 4 to 9 ft.

$$

437 
FZAK61 PAFC 171158
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
358 AM AKDT Sun Sep 17 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.

PKZ399-180045-
358 AM AKDT Sun Sep 17 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 989 mb low at 57N 151W will move to 55N 145W at 992mb this
afternoon...then weaken and move into the eastern Gulf by Mon 
morning. A front will move into the western Gulf Mon
morning...then move into the eastern Gulf through Tue.

$$

PKZ351-180045-
Gulf of Alaska Offshore North of 57N and West of 144W-
358 AM AKDT Sun Sep 17 2017

.TODAY...NE wind 10 to 15 kt. Seas 9 to 15 ft.
.TONIGHT...NW wind 10 to 15 kt. Seas 7 to 12 ft.
.MON...SW wind 10 to 15 kt. Seas 5 to 9 ft.
.MON NIGHT...W wind 10 to 25 kt. Seas 4 to 8 ft.
.TUE THROUGH WED...W wind 10 to 25 kt. Seas 4 to 7 ft.
.THU...S wind up to 15 kt. Seas 3 to 6 ft.

$$

PKZ352-180045-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
358 AM AKDT Sun Sep 17 2017

...GALE WARNING TODAY...

.TODAY...NW wind 20 to 35 kt diminishing to 10 to 25 kt in the
afternoon. Seas 13 to 20 ft.
.TONIGHT...NW wind 10 to 20 kt. Seas 9 to 16 ft.
.MON...W wind 10 to 20 kt. Seas 7 to 10 ft.
.MON NIGHT...W wind 15 to 30 kt. Seas 6 to 10 ft.
.TUE...NW wind 10 to 25 kt. Seas 5 to 10 ft.
.WED THROUGH THU...SW wind up to 20 kt. Seas 3 to 7 ft.

$$

184 
FZAK61 PAFC 172305
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
305 PM AKDT Sun Sep 17 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.

PKZ399-181245-
305 PM AKDT Sun Sep 17 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 992 mb low near 55n 142w moves southeast and weakens. A 
weather front moves to the western Gulf Monday morning and to the 
southeast Gulf Tuesday morning. 

$$

PKZ351-181245-
Gulf of Alaska Offshore North of 57N and West of 144W-
305 PM AKDT Sun Sep 17 2017

.TONIGHT...NW wind 10 to 15 kt. Seas 7 to 12 ft.
.MON...SW wind 10 to 15 kt. Seas 7 ft.
.MON NIGHT...NW wind 10 to 20 kt. Seas 6 ft.
.TUE...NW wind 10 to 20 kt. Seas 4 to 7 ft.
.TUE NIGHT...W wind 10 to 20 kt. Seas 5 ft.
.WED THROUGH FRI...SW wind up to 20 kt. Seas 3 to 7 ft.

$$

PKZ352-181245-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
305 PM AKDT Sun Sep 17 2017

.TONIGHT...NW wind 10 to 20 kt. Seas 9 to 15 ft.
.MON...W wind 10 to 25 kt. Seas 9 ft.
.MON NIGHT...NW wind 15 to 30 kt. Seas 7 to 11 ft.
.TUE...NW wind 15 to 25 kt. Seas 5 to 9 ft.
.TUE NIGHT...W wind 15 kt. Seas 5 ft.
.WED THROUGH FRI...SW wind up to 20 kt. Seas 3 to 8 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
512 AM AKDT Fri Sep 15 2017

.ANALYSIS AND UPPER LEVELS...
Water vapor satellite imagery shows a double-barreled low over
the Bering and Arctic early this morning. The low center over the
Bering is stacked and will be the main weather challenge for the
short term forecast. The ridge which was over the Alcan border
yesterday, shifted further east across British Columbia. At the
surface, a weak trough pulled a front inland across Southcentral
overnight bringing a few showers across the region. A weak
boundary remains along the northeast gulf and Prince William Sound
with showers continuing to develop along the boundary. To the
west, the low over the central Bering waters is rapidly deepening
about 200 miles west of the Pribilof Islands and is approximately
982 mb early this morning. Gusty southeasterly flow along the
eastern waters had reported gusts between 40 to 50 mph with winds
across the western waters gusting up to the same strength out of
the west.

&&

.MODEL DISCUSSION...
Models continue to be in relatively good agreement with the
overall synoptic pattern through Saturday, however they still
have differences with the strength and track of the quickly
developing storm system over the Bering. The ECMWF continues to be
the favored model for the storm track and strength from the 00Z
models. Higher resolution of the NAM was used for the Gulf and
local edit areas of Southcentral.

&&

.AVIATION...
PANC...VFR conditions are expected through the next TAF package.
Light southerly winds are expected to increase this afternoon as
the storm system to the west strengthens. Winds are expected to
taper off late tonight as the pressure re-orients to a down inlet
flow ahead of an approaching front. Kept winds southeasterly
overnight as models have struggled with a new low center expected
to develop early Saturday morning over the western gulf.

&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...

A weakening front continues to support widespread showers along
the northern Gulf of Alaska Coast this morning and in the western
Cook Inlet and Susitna Valley. A coastal ridge and low level jet
remains intact this morning, which continues to support broad
southeasterly downsloping winds across the west Kenai Peninsula,
Anchorage Bowl and Matanuska Valley. Although moisture is
sufficient, downsloping continues to significantly limit rain in
these areas. There is a little more uncertainty for the Saturday
forecast as a triple point low develops in the Gulf of Alaska. The
latest models are trending in a more well-developed low with a
more potent but brief low level jet along the north Gulf of Alaska
coast. Models are also trending for more widespread moderate to
heavy rains along the coast which could result in a fairly soggy
Saturday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
An approaching Bering Sea front and low pressure system will
return rain and gusty winds to the area this afternoon. The front
quickly washes out late tonight leaving much of the mainland in a
moist cyclonic flow and more showery precipitation rather than
widespread rain. The responsible upper level trough lingers
through the weekend leaving a chance of showers and relatively
light northerly winds.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The focus remains on the developing fall storm west of the
Pribilof Islands. The swath of strongest winds still looks to clip
the Islands, especially Saint George as the system pulls to the
east this evening. The High Wind Watch has been upgraded to a High
Wind Warning. Rain will come with the winds on the backside of
the system overnight. The strongest winds will shift toward the
Alaska Peninsula overnight into Saturday before slowly tapering
down through the weekend.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The long term outlook will feature a somewhat complicated pattern
beginning next week with various model solutions and little
consensus, keeping overall forecast confidence past day 4 low at
this point. To start, a strong low pressure system originating in
the Bering Friday/Saturday will move into the Gulf of Alaska and
then east into Southeast Alaska while weakening by early next
week. On Monday, models are showing a weak shortwave trough
dropping out of the Arctic, riding the back end of the upper level
trough over the state, which will lead to more unsettled weather
for southwest and southcentral Alaska keeping temperatures cool.
By midweek, a low pressure system supported by an active sub-
tropical jet forms south of the western Aleutians then heads east
skirting the island chain. Models diverge greatly at this point
with the GFS taking the system too far south to impact out area,
while the EC takes a more northerly trajectory bringing a front
with heavy rain up through southwest and eventually into
southcentral by Wednesday evening. Since the EC has been more
consistent over the past week with handling a more amplified flow,
the forecast trended towards the later solution.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning...195.
MARINE...Storms..165 170 179
Gales...150 155 160 171 172 173 174 175 176 180 181 185.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...KH
SOUTHCENTRAL ALASKA...ELN
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ML
LONG TERM...KVP