Gale Warning 263, NWS Anchorage, AK

228 
FZAK61 PAFC 221153
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
353 AM AKDT SAT APR 22 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.

PKZ399-230145-
353 AM AKDT SAT APR 22 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A STALLED FRONT OVER THE SOUTHERN AND CENTRAL GULF WILL WEAKEN IN
PLACE THROUGH TONIGHT. WEAK TROUGHS WILL MOVE THROUGH THE SOUTHERN
AND WESTERN GULF TONIGHT THROUGH SUN NIGHT.

$$

PKZ351-230145-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
353 AM AKDT SAT APR 22 2017

.TODAY...E WIND 20 TO 30 KT. SEAS 14 FT. RAIN.
.TONIGHT...E WIND 15 TO 25 KT. SEAS 11 FT.
.SUN...E WIND 20 KT. SEAS 9 FT.
.SUN NIGHT...E WIND 20 KT. SEAS 7 FT.
.MON THROUGH WED...S WIND 10 TO 20 KT. SEAS 5 FT.

$$

PKZ352-230145-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
353 AM AKDT SAT APR 22 2017

.TODAY...E WIND 15 TO 30 KT. SEAS 15 FT. RAIN.
.TONIGHT...SE WIND 10 TO 20 KT. SEAS 11 FT.
.SUN...E WIND 15 KT. SEAS 9 FT.
.SUN NIGHT...SE WIND 15 KT. SEAS 7 FT.
.MON THROUGH WED...SW WIND UP TO 15 KT. SEAS 7 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
448 AM AKDT Fri Apr 21 2017

.ANALYSIS AND UPPER LEVELS...

A very persistent pattern is on tap for the Anchorage metro area
this weekend. With ridging in place...expect more mild and dry
weather with afternoon temperatures running above normal for late
April.

Over the western Aleutians there is a frontal boundary. Over the
Bering Sea the remnants of a closed low continues to churn near
the Pribilof Islands. There is an occluded system approximately
150 miles south of Kodiak.

&&

.MODEL DISCUSSION...
The mass fields of the ECMWF and the GFS are very consistent with
the ridge axis bisecting British Columbia and southern AK. Very
confident that the subsidence pattern will persist over the
Anchorage metro area through the weekend. The ECMWF and the GFS
are also in sync with evolution of the low over the Bering as it
retrogrades...decays and gets absorbed into the longwave pattern.
There is a skosh of variation with the low over the western
Aleutians but the structural divergence won't have significant
sensible weather impacts through the weekend. The persistence of
the ridge over BC will slow the progression of the system churning
over the Gulf of Alaska. Given the run to run continuity with the
ridge...adjusted the pops to account for a slower progression of
the precipitation shield.

&&

.AVIATION...
PANC...VFR conditions are expected for the ensuing 24 hr period.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
High pressure will remain over Southcentral Alaska through
Saturday, and slowly drift north on Saturday night. A weather
front in the southern Gulf will move north today and push into
Kodiak Island tonight. This front will stall and weaken on
Saturday as the parent low moves westward into the Alaska
Peninsula. Some precipitation may move as far north as the Kenai
Peninsula, but most will stay over the Gulf and Kodiak Island.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...

Satellite imagery this morning shows the closed upper low over the
eastern Bering shifting northwestward. As this energy becomes
absorbed into the greater complex low over the western
Aleutians, the upper-level low will quickly exit to the west
today. Light snow showers over Nunivak Island and the Kuskokwim
Delta Coast this morning will dissipate today as the upper-level
forcing moves west.

A front south of the Gulf of Alaska will move inland over the
Alaska Peninsula this afternoon, then move into the eastern
Bering tonight. The strongest precipitation associated with this
front will fall on the windward side of the Aleutian Range
tonight through Saturday night. With warm, moist air moving in
with the front, the precipitation type will primarily be rain.
Gusty offshore winds associated with the front will peak over the
Alaska Peninsula Saturday morning and diminish through the day as
the front moves into the eastern Bering.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...

The upper-level jet will remain well to the south of the
Aleutians...which will allow the complex low over the western and
central Aleutians to remain anchored in place through the
weekend. The associated gale-force frontal boundary will become
further occluded as it pushes northward from the Aleutians into
the western and central Bering tonight. As the front shifts
northward, the core of the strongest winds will move from the
Aleutian Chain this morning to the western Bering by Saturday
morning.  As multiple low centers form within the broad complex
low...the showery weather pattern with broad marine stratus will
continue through the weekend over the western Bering and
Aleutians.

&&

.LONG TERM FORECAST (Days 3 through 7)...

The long term forecast continues to show a bit of a pattern change
for the mainland of Alaska. The dominant high pressure that has
produced so many cloudless days around much of the state recently
is in the process of weakening, and as the weekend progresses more
substantial cloudiness (with sunny breaks, though) will slowly
spread up Cook Inlet and also into Southwest Alaska. By early next
week, most areas will be under the influence of general (but
weak) low pressure, with diurnal (afternoon/evening) clouds and
showers even across the typical inland locations. Meanwhile, out
west, generally unsettled but benign weather will continue over
much of the Bering Sea and Aleutians. Despite the increased
cloudiness around the state, temperatures should stay seasonably
mild across most of the area.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 131 132 138 150 173 174 175 176 178.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...PS
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...RD
LONG TERM...AMD