Gale Warning 661, NWS Anchorage, AK

920 
FZAK62 PAFC 101244
OFFALU

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
344 AM AKST THU NOV 10 2016

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.

PKZ499-110215-
344 AM AKST THU NOV 10 2016
.SYNOPSIS FOR CENTRAL BERING SEA...
A 983 MB SOUTH KAMCHATKA LOW MOVES TO 50N 173E AT 979 THEN SHIFTS
INTO THE NORTH PACIFIC AND DISSIPATES FRI NIGHT. A 981 MB LOW
FORMS AT 49N 174W AND MOVES TO 54N 160W SAT MORNING. THE ASSOCIATED
FRONT MOVES INTO THE GULF OF ALASKA THROUGH SAT MORNING.

$$

PKZ411-110215-
BERING SEA OFFSHORE WEST OF 180 AND EAST OF THE INTERNATIONAL
DATELINE-
344 AM AKST THU NOV 10 2016

.TODAY...E WIND 15 TO 30 KT. SEAS 6 TO 11 FT.
.TONIGHT...NE WIND 20 TO 30 KT. SEAS 8 TO 13 FT.
.FRI...N WIND 20 TO 30 KT. SEAS 8 TO 13 FT. SNOW.
.FRI NIGHT...N WIND 20 TO 30 KT. SEAS 10 TO 13 FT.
.SAT THROUGH MON...NW WIND 15 TO 25 KT. SEAS 8 TO 13 FT.

$$

PKZ412-110215-
BERING SEA OFFSHORE 171W TO 180 AND NORTH OF 56N-
344 AM AKST THU NOV 10 2016

...GALE WARNING FRIDAY...

.TODAY...N WIND 15 TO 30 KT. SEAS 7 TO 12 FT.
.TONIGHT...N WIND 20 TO 30 KT. SEAS 8 TO 13 FT. SNOW.
.FRI...N WIND 25 TO 35 KT. SEAS 9 TO 13 FT. SNOW.
.FRI NIGHT...N WIND 25 TO 40 KT. SEAS 13 TO 19 FT.
.SAT THROUGH SUN...N WIND 25 TO 40 KT. SEAS 13 TO 21 FT.
.MON...NW WIND 25 KT. SEAS 9 TO 14 FT.

$$

PKZ413-110215-
BERING SEA OFFSHORE 171W TO 180 AND SOUTH OF 56N-
344 AM AKST THU NOV 10 2016

.TODAY...NE WIND 15 TO 25 KT. SEAS 7 TO 14 FT.
.TONIGHT...NE WIND 25 KT. SEAS 10 FT.
.FRI...N WIND 30 KT. SEAS 12 FT. SNOW.
.FRI NIGHT...N WIND 25 TO 35 KT. SEAS 11 TO 17 FT.
.SAT THROUGH MON...NW WIND 25 TO 40 KT. SEAS 13 TO 21 FT.

$$

PKZ414-110215-
BERING SEA OFFSHORE EAST OF 171W-
344 AM AKST THU NOV 10 2016

.TODAY...N WIND 30 KT. SEAS 11 TO 14 FT.
.TONIGHT...N WIND 15 TO 30 KT. SEAS 8 TO 13 FT. SNOW.
.FRI...N WIND 15 TO 30 KT. SEAS 8 TO 13 FT. SNOW AND RAIN.
.FRI NIGHT...N WIND 25 TO 40 KT. SEAS 9 TO 14 FT.
.SAT THROUGH MON...NW WIND 25 TO 40 KT. SEAS 11 TO 19 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
547 AM AKST WED NOV 9 2016

.ANALYSIS AND UPPER LEVELS...

A double-barreled longwave trough remains centered over the North
Pacific along the 50th parallel between 145W and 170W. A pair of
powerful storm-force cyclones is situated along the eastern-most
and western-most ends of this trough. The eastern low is well
south of Kodiak, and the western Gulf of Alaska. While the
westernmost storm-force low is moving south of the Eastern
Aleutians, and southern Alaska Peninsula toward the North
Pacific. A smaller-scale mid-level low is moving west from
Shelikof Strait to the northern Alaska Peninsula around the
northern periphery of the longwave trough. The east-to-west
movement of this feature, combined with an unstable air mass, is
allowing for vigorous rain showers to move across the northern
Gulf of Alaska into Prince William Sound and the Eastern Kenai
Peninsula. Meanwhile, over inland valleys a much colder air mass
is in place with northerly offshore flow contributing to much
drier conditions along with steep low-level inversions, as seen
from the Bethel and Anchorage 00z soundings from Tuesday
afternoon. Strong northerly cold advection persists over the
Bering region extending south through the Aleutians on the
backside of the storm-force low. The upper levels and near-
surface temperatures are marginal enough to yield precipitation-
type concerns (rain/snow showers) in a highly unstable low-level
environment.

&&

.MODEL DISCUSSION...

Models are in general agreement that the strengthening eastern-
most storm-force low south of Kodiak will become the primary low,
and absorb the western-most low south of the Eastern
Aleutians/Alaska Peninsula today. This low pushes a strong gale-
to storm-force low to the North Gulf Coast by this evening. While
another wave moves along this front into Thursday with a east-
to-west orientation over the northern Gulf of Alaska. The NAM
still remains relatively weaker with regards to low strength when
compared to the other models, and was not preferred with this
feature. Precipitation-type has been a challenge over Southcentral
in recent days, but with warming air in place combined with
increased downslope drying in some areas it is now a bit less of
an issue. Although, temperatures did drop a little lower than
anticipated last night especially across the Anchorage Bowl. Thus,
overall forecast confidence is generally high.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist through early
Wednesday evening, and possibly through the remainder of the TAF
period. However, there does remains some possibility that a low
pressure wave that will move west across the northern Gulf
tomorrow night, and help bring a brief period of reduced ceilings
and some light rain to the PANC vicinity possibly between 08z and
15z.

&&

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

The next couple of days will be characterized by mostly cloudy
conditions with chances for freezing rain and rain inland, and
rain along the coast. The responsible system is deepening in the
northeastern Pacific currently, and will send a gale-storm force
frontal boundary up against the north Gulf coast tonight, bringing
steady rain with gusty winds to the area. As a difluent jet and
upper shortwave move overhead tonight there is a chance for some
precipitation to make it over the mountains. The thermal profile
will be pretty tricky as a warm-nose will be in place aloft while
temperatures around the Anchorage Bowl/Mat-Su will be below
freezing. Any rain should be light, however, any freezing on
surfaces could make for difficult conditions.

Thursday brings another wave riding the front and another round of
rain from the Gulf coast and inland as well. Temperatures during
the day will hit the mid to upper 30s, falling down into the 20s
at night making rain and freezing rain the predominant
precipitation types for this pattern.

&&

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

A weak wave that is beginning to move into Bristol Bay from the
western Gulf will bring a wintry mix of rain or light freezing
rain to much of Bristol Bay this morning. This is indicated in the
12z King Salmon sounding where a freezing layer appears at ~600
ft off the surface that is deep and moist enough to keep any
precipitation as rain. The rain this morning will be relatively
light and spotty. However, with temperatures beginning to rise
above freezing in eastern Bristol Bay significant areas of
freezing rain are not expected. Most of the freezing rain should
occur over interior Bristol Bay to the north, and west of King
Salmon where temperatures will struggle to rise above freezing
this morning. A front over the gulf then quickly moves into
Bristol Bay this evening, bringing more widespread and heavier
precipitation to the southwest Mainland through Thursday. With
cooler air and heavier precip rates from this front, most of the
precipitation will switch over to wet snow fairly quickly. Most
of the accumulating snow with this front should occur from
Dillingham north, and west into Bethel where a few inches of new
snowfall is possible.

&&

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

The broad area gale force winds over the central Bering and
Aleutians will begin to diminish this morning as the low continues
to weaken as it moves into the North Pacific. This leaves
widespread rain, and snow showers over the Bering in its wake
through today with persistent cold air advection. A gale force
front moves into the Western Aleutians on Thursday morning, but
with high pressure beginning to descend into the Bering this front
struggles to make it into the Central Aleutians before dissipating
late Thursday.

&&

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

The long range forecast will be characterized by low pressure
south of mainland Alaska. This will be seen as two main lows, but
as the first diminishes Friday it is replaced by another low from
the North Pacific Friday night. This new low lasts into early
next week. Even though there is some disagreement amongst the
models on exact timing and placement of these two lows, impacts
should remain similar. This setup brings southerly flow and more
warm air to the southern Mainland, while the Bering/Aleutians
will see northerly flow with cold air advection. The heaviest
precipitation will be along the north Gulf coast, and looks to be
warm enough to fall as predominately rain.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Storm Warning...119.
         Gale Warning...120 125 130 131 132 136 137 138 139 140
                        150 155 160 165 170 172 173 174 175 176
                        177 178 179 180 181 185.

&&

SYNOPSIS AND MODEL DISCUSSION...CC
SOUTHCENTRAL ALASKA...MTL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DEK
LONG TERM...DK