Gale Warning 456, NWS Anchorage, AK

278 
FZAK61 PAFC 072329
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
329 PM AKDT SUN AUG 7 2016

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.

PKZ399-081345-
329 PM AKDT SUN AUG 7 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 1000 MB LOW AT 59N 152W DISSIPATES TONIGHT. HIGH PRESSURE OVER
THE NORTH GULF COAST AND SOUTHEAST ALASKA EASES SOUTHEASTWARD
THROUGH MON NIGHT. WEAK TROUGHS MOVE THROUGH THE WESTERN GULF OF
ALASKA THROUGH MON MORNING SPREADING OVER SOUTHEASTERN ALASKA
THROUGH TUE EVENING.

$$

PKZ351-081345-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
329 PM AKDT SUN AUG 7 2016

.TONIGHT...SW WIND 20 KT. SEAS 9 TO 12 FT.
.MON...SW WIND 15 KT. SEAS 8 FT.
.MON NIGHT...SW WIND 15 KT. SEAS 6 FT.
.TUE...SW WIND 15 KT. SEAS 6 FT.
.TUE NIGHT...SW WIND 10 KT. SEAS 5 FT.
.WED THROUGH FRI...SW WIND 15 KT. SEAS 5 FT.

$$

PKZ352-081345-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
329 PM AKDT SUN AUG 7 2016

.TONIGHT...SW WIND 20 KT. SEAS 8 TO 12 FT.
.MON...SW WIND 15 KT. SEAS 8 FT.
.MON NIGHT...W WIND 15 KT. SEAS 7 FT.
.TUE...SW WIND 15 KT. SEAS 6 FT.
.TUE NIGHT...SW WIND 15 KT. SEAS 6 FT.
.WED THROUGH FRI...SW WIND UP TO 20 KT. SEAS 6 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
407 PM AKDT SAT AUG 6 2016

.ANALYSIS AND UPPER LEVELS...

A low pressure system centered near Nunivak Island continues to
drive much of the weather across both Southcentral and Southwest
Alaska today. As this low remains nearly stationary in the
eastern Bering Sea, several associated fronts continue to impact
the region. Currently one front is pushing inland along the
north gulf coast and slowly dissipating and supporting local gap
winds and showers. A second front is currently developing across
the Alaska Peninsula and poised to intensify rapidly as it pushes
eastward into the Gulf of Alaska tonight. Currently this front is
bringing widespread rain and showers to portions of Bristol Bay.

&&

.MODEL DISCUSSION...

While models are in generally good agreement, today they have
shown poor run to run consistency, particularly with respect to
the intensification of the front that will progress across the
western gulf to eastern gulf starting late tonight into tomorrow.
Models today indicate a front with much stronger winds and better
defined pressure gradients which will result in stronger winds
through local gaps. However, due to poor run to run consistency,
there is some uncertainty in the intensity and timing of the
front.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The large upper level low will remain centered near Nunivak island
through the weekend. A developing frontal wave south of the Alaska
Peninsula will swing into the southwestern Gulf this evening,
cross Kodiak Island tonight and then push into the northern Gulf
on Sunday. This frontal system will bring a good bit of rain to
the Gulf Coast as well as windy conditions. East to southeast
wind will increase to around 35 knots in portions of the northern
Gulf as well as Prince William Sound late tonight through Sunday
with strong winds channeling through Turnagain Arm, the Knik and
Copper River Valleys and other similarly oriented terrain gaps as
well. Rain will change over to showers Sunday night and Monday
after the front swings through, though conditions will remain
generally damp under southwesterly flow aloft.

&&

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

A rather impressive looking occluded low on satellite imagery is
spinning off the coast near Nunivak Island. This surface feature
will move inland tonight with showers turning to more stratiform
rain over the Kuskokwim Delta. Strong east to southeast winds are
also accompanying this low with the strongest core of winds along
the Kuskokwim Delta coastline. Elsewhere, showers will be more
dominant as some degree of cross-barrier flow across the Alaska
Range will help keep deep moisture from turning those showers into
widespread rain. Thereafter, the low will move inland then stall
over the Kuskokwim Delta, keeping a moist and showery regime over
the region through Monday.

&&

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

An impressive low, at least on satellite imagery, has wrapped up
over the Eastern Bering Sea this afternoon, with the strongest
core of winds extending from the Pribilof Islands to the Kuskokwim
Delta coast. The front has moved into the Gulf of Alaska, with a
rather large dry slot carving out over most of the Eastern
Aleutians. A warm front over the Western and Central Aleutians is
weakening, but is still bringing some rain and fog to those areas.
With time, the front will weaken and move southeast while the
upper low weakens and moves inland, so rather quiet weather will
develop over the region through Monday.

&&

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

Models are in good agreement that the upper level low over
western Alaska will steadily weaken through Wednesday. Rain over
south central Alaska will become more showery by midweek and continue
into the coming weekend. Ridging will move into southwest Alaska by
Tuesday night that will also reduce some of the shower activity,
but a low moving rapidly out of Siberia will redevelop
precipitation over southwest Alaska Wednesday.

The next low will be the remnants of a tropical storm system which
will enter the western Aleutian Islands Wednesday evening and
absorb the Siberian low over the central Bering Sea. This merger
will enhance precipitation as it moves across the Bering Sea into
southwest Alaska Thursday into Saturday.

Winds associated with the remnants of the tropical storm will
increase to gales over the extreme western Aleutians on Thursday,
but the main impact will be seas made higher by an extremely long
fetch across the north Pacific. However, there remains significant
uncertainty with both wind speeds as well as combined seas
beginning late Wednesday and lasting into the weekend. The
forecast utilized the GFS and WPC solutions.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE 119 125 352.
FIRE WEATHER...DONE.

&&

SYNOPSIS AND MODEL DISCUSSION...EN
SOUTHCENTRAL ALASKA...JR
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...DS