Gale Warning 344, NWS Anchorage, AK

119 
FZAK62 PAFC 141103
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
303 AM AKDT Wed Jun 14 2017

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-150115-
303 AM AKDT Wed Jun 14 2017
.SYNOPSIS FOR CENTRAL BERING SEA...

Bogoslof Volcano at 54N 168W remains active.

A 987 mb low at 52N 173E moves to 47N 171W at 994 mb with the 
associated front decaying over the Aleutians through Fri morning.
High pressure remains over the Eastern Bering through Fri 
morning.

$$

PKZ411-150115-
Bering Sea Offshore West of 180 and East of the International
Dateline-
303 AM AKDT Wed Jun 14 2017

.TODAY...E wind 15 to 30 kt. Seas 9 to 13 ft.
.TONIGHT...NE wind 15 to 25 kt. Seas 8 to 11 ft.
.THU...NE wind 10 to 25 kt. Seas 6 to 10 ft. Patchy fog.
.THU NIGHT...NE wind up to 20 kt. Seas 4 to 8 ft.
.FRI...NW wind up to 15 kt. Seas 4 ft.
.SAT THROUGH SUN...W wind up to 15 kt. Seas 4 ft.

$$

PKZ412-150115-
Bering Sea Offshore 171W to 180 and North of 56N-
303 AM AKDT Wed Jun 14 2017

.TODAY...E wind 15 to 25 kt. Seas 5 to 9 ft. Patchy fog.
.TONIGHT...E wind 10 to 20 kt. Seas 6 to 9 ft. Patchy fog.
.THU...NE wind 10 to 20 kt. Seas 4 to 7 ft. Patchy fog.
.THU NIGHT...NE wind up to 15 kt. Seas 4 to 7 ft.
.FRI...NW wind up to 15 kt. Seas 3 to 5 ft.
.SAT THROUGH SUN...W wind up to 15 kt. Seas 4 ft.

$$

PKZ413-150115-
Bering Sea Offshore 171W to 180 and South of 56N-
303 AM AKDT Wed Jun 14 2017

.TODAY...E wind 15 to 30 kt. Seas 8 to 12 ft.
.TONIGHT...E wind 10 to 25 kt. Seas 6 to 11 ft.
.THU...E wind 15 to 25 kt. Seas 6 to 9 ft.
.THU NIGHT...NE wind 10 to 20 kt. Seas 6 ft.
.FRI THROUGH SUN...NW wind up to 20 kt. Seas 3 to 6 ft.

$$

PKZ414-150115-
Bering Sea Offshore East of 171W-
303 AM AKDT Wed Jun 14 2017

.TODAY...E wind 10 to 20 kt. Seas 3 to 6 ft. Patchy fog.
.TONIGHT...E wind 10 to 20 kt. Seas 3 to 6 ft. Areas of fog.
.THU...E wind 10 to 20 kt. Seas 3 to 6 ft. Areas of fog.
.THU NIGHT...N wind up to 15 kt. Seas 3 ft.
.FRI THROUGH SUN...N wind up to 15 kt. Seas 3 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
513 AM AKDT Tue Jun 13 2017

.ANALYSIS AND UPPER LEVELS...
The remnants of the deformation band that brought rain to much of
the interior on Monday has now moved southward into Southcentral
in advance of a cold upper level trough descending into the
eastern interior. This is beginning to bring rain to the Southwest
Mainland and Susitna Valley, as well as far south as the
Anchorage Bowl. Rain will continue to spread southward today as
the upper trough approaches to the north. The cold air associated
with the trough provided enough instability to bring nocturnal
thunderstorms to the central Interior overnight, and may bring a
few strikes to the Talkeetna Mountains and Kuskokwim Valley this
afternoon. This trough is also forcing the upper level low that
brought rain and cloudcover to the South Mainland on Monday into
the open waters of the Gulf.

Over the Bering Sea, weak high pressure centered east of the
Pribilof Islands has allowed for fog/stratus to develop along the
Southwest coast. This is however beginning to dissipate in
advance of a front moving through the Central Aleutians. This
front brought rain and nearly gale force gusts to the Western
Aleutians, which will spread eastward today.

&&

.MODEL DISCUSSION...
Very little has changed in the overall model performance in the
past 24 hours as they continue to be in very good synoptic scale
agreement. The challenge continues to be determining how far west
rainfall will spread into Southcentral today. The GEM regional
appears to be the best initializing model overnight, as it is the
only model to bring rainfall into the Susitna Valley and Anchorage
Bowl. As a result there is increasing confidence that rain will
spread into much of the Cook Inlet region today. A second concern
surrounds how much instability will develop along the Talkeetna
Mountains and Southwest Mainland with the upper level trough this
afternoon. The strongest model agreement exists over the Kuskokwim
Valley, upstream of where nocturnal thunderstorms have formed in
the interior, and as a result this is also where the highest
confidence in thunderstorm development exists.

&&

.AVIATION...
PANC...Rain will continue moving through the area this morning
producing ceilings around 5000 ft, dropping at times to MVFR in
heavier bands. There is lower confidence on the exact timing that
ceilings will improve above 5000 ft this afternoon, with some
models keeping ceilings lower into the evening. The general trend
should be for improving conditions this afternoon or evening as
widespread rain breaks up into showers. Winds will remain light
and variable until late tonight when southerly winds will begin to
increase.

&&

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

Water vapor imagery this morning indicates an upper level wave
pushing southward across the Copper River Basin, and Susitna
Valley with dry air behind it. Ahead of this wave radar shows a
wide swath of rain impacting the Anchorage Bowl, Susitna Valley
and the Kenai Peninsula. As this wave moves south conditions will
gradually improve throughout the day today from north to south as
drier air slowly trickles in. However, with enough cold air aloft
in place, diurnal heating results in the redevelopment of showers
across the northern Susitna Valley and the Copper River Basin,
and a few lightning strikes are possible.

Showers will develop again in the afternoon tomorrow. As showers
will be mainly forced by diurnal heating, showers will be the most
intense over elevated terrain where a few lightning strikes are
again possible. There is some uncertainty among models as to
the extent that showers will impact lower elevations.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The Lower Kuskokwim Valley has a thermal trough developing today.
This synoptic feature combined with diurnal heating enhances the
possibility of a showery regime with isolated thunderstorms by
the afternoon time-frame. Due to the storm motion being northerly,
any convective showers will track into the Bristol Bay interior
by the late Tuesday afternoon through the evening hours. By
Wednesday the thermal trough traverses westward over the Kuskokwim
Delta, and the Kuskokwim/Ahklun Mountains. Therefore, look for
isolated thunderstorms Wednesday afternoon/evening hours over
majority of the Southwest Alaska region. Meanwhile, the other
forecast challenge is the stratus/fog. Look for areas of fog along
the Alaska Peninsula coinciding with the onshore flow, and
clearing skies allowing radiational cooling this morning. The
marine layer stratus/fog will likely remain along the Bristol Bay,
and the Alaska Peninsula coastline during Wednesday morning with
the showery regime keeping the fog from developing in the interior.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The high pressure over the northern Bering remains almost
stationary with a ridge extending into the eastern Bering. This
feature aids in fog development over the aforementioned region
heading into the midweek time-frame. While the gale force low west
of Shemya gradually tracks over the Western Aleutians by Wednesday.
The associated front swings through into the western Bering, and
extends eastward through the Central Aleutians by Wednesday morning.
This system brings widespread rain and easterly winds to the lower
Bering, and majority of the Aleutian Chain.

&&

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

On Thursday, upper level ridging and warming temperatures over
interior Alaska will bring about the return of offshore flow with
drying conditions and warming temperatures across southern Alaska.
This means more sunshine will return, helping temperatures warm
back to above normal levels for much of the area. Afternoon
showers and a few storms are still possible, especially over the
mountains, but little in the way of large-scale weather systems
are expected to impact Southcentral.

A persistent area of low pressure will slowly move eastward south
of the Aleutians right through the weekend. Thus, a long period of
persistent easterly winds, rain, and high seas should be expected
in association with that feature.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale...175 176 177.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...DEK
SOUTHCENTRAL ALASKA...ELN
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PD
LONG TERM...JW