Gale Warning 782, NWS Anchorage, AK

567 
FZAK61 PAFC 200019
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
319 PM AKST MON DEC 19 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.

PKZ399-201500-
319 PM AKST MON DEC 19 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 981 MB LOW AT 55N 152W TUE MORNING MOVES TO 58N 141W AT 978 MB
TUE AFTERNOON THEN DISSIPATES WED MORNING. A 980 MB LOW FORMS AT
58N 155W TUE MORNING AND MOVES TO 59N 149W AT 987 MB WED MORNING
THEN SLIPS TO 57N 147W AT 989 MB WED AFTERNOON.

$$

PKZ351-201500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
319 PM AKST MON DEC 19 2016

.TONIGHT...SW WIND 15 TO 30 KT. SEAS 13 TO 18 FT.
.TUE...W WIND 10 TO 25 KT. SEAS 12 TO 18 FT.
.TUE NIGHT...SW WIND 10 TO 25 KT. SEAS 11 TO 15 FT.
.WED...SW WIND UP TO 20 KT. SEAS 11 TO 15 FT.
.WED NIGHT...NW WIND 10 TO 25 KT. SEAS 9 TO 14 FT.
.THU THROUGH SAT...SE WIND 10 TO 25 KT. SEAS 5 TO 10 FT.

$$

PKZ352-201500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
319 PM AKST MON DEC 19 2016

...GALE WARNING THROUGH TUESDAY...

.TONIGHT...SW WIND 25 TO 40 KT. SEAS 17 TO 23 FT. RAIN SHOWERS.
.TUE...W WIND 20 TO 35 KT. SEAS 17 TO 22 FT.
.TUE NIGHT...SW WIND 15 TO 30 KT. SEAS 15 TO 20 FT.
.WED...W WIND 15 TO 30 KT. SEAS 15 TO 18 FT.
.WED NIGHT...NW WIND 15 TO 30 KT. SEAS 12 TO 17 FT.
.THU...NW WIND 25 KT. SEAS 10 TO 14 FT.
.FRI...W WIND UP TO 20 KT. SEAS 5 TO 10 FT.
.SAT...S WIND 10 KT. SEAS 9 TO 17 FT.

$$

286 
FZAK61 PAFC 201224
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
324 AM AKST TUE DEC 20 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.

PKZ399-210245-
324 AM AKST TUE DEC 20 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 982 MB LOW NEAR 54N 152W MOVES INTO THE NORTHEAST GULF THIS
EVENING AND DISSIPATES. ANOTHER 983 MB LOW FORMS NEAR 57N 156W
THIS AFTERNOON...MOVES TO 58N 151W AT 987 MB LATE TONIGHT...THEN
MOVES TO 57N 144W AT 994 MB LATE WED NIGHT.


$$

PKZ351-210245-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
324 AM AKST TUE DEC 20 2016

.TODAY...SW WIND 10 TO 20 KT. SEAS 12 TO 18 FT.
.TONIGHT...SW WIND 10 TO 25 KT. SEAS 11 TO 16 FT.
.WED...SW WIND 10 TO 15 KT. SEAS 11 TO 15 FT.
.WED NIGHT...NW WIND 15 TO 30 KT. SEAS 9 TO 14 FT.
.THU...NW WIND 15 TO 25 KT. SEAS 8 TO 13 FT.
.FRI THROUGH SAT...SE WIND 10 TO 25 KT. SEAS 3 TO 8 FT.

$$

PKZ352-210245-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
324 AM AKST TUE DEC 20 2016

.TODAY...W WIND 15 TO 30 KT. SEAS 17 TO 22 FT.
.TONIGHT...SW WIND 15 TO 30 KT. SEAS 15 TO 21 FT.
.WED...W WIND 15 TO 30 KT. SEAS 15 TO 18 FT.
.WED NIGHT...NW WIND 15 TO 30 KT. SEAS 13 TO 17 FT.
.THU...NW WIND 25 KT. SEAS 9 TO 14 FT.
.FRI THROUGH SAT...S WIND 10 TO 20 KT. SEAS 6 TO 11 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
438 PM AKST Sun Dec 18 2016

.ANALYSIS AND UPPER LEVELS...
There is a vertically stacked low over the southern Bering Sea.
There is an upper level high over the northern Bering creating a
Rex block. The surface low is still quite strong at 950 mb, but
slowly weakening. There is an upper level low over the northwest
Gulf of Alaska that is in the process of "closing off". The
associated surface low (around 963 mb) is centered over the
northern tip of Kodiak island, with a strong front draped across
the northern Gulf coast. There is a slowly retrograding upper low
over west- central Alaska. The main jet stream is over the north
Pacific well to the south of the state.

&&

.MODEL DISCUSSION...
The numerical models are in good agreement today. There are some
differences in how they handle the development of a low moving
across the Gulf on Monday, but these differences are minor. The
GFS and NAM were the preferred solutions. Forecast confidence is
a little higher than normal.

&&

.AVIATION...
PANC...VFR conditions and light winds will continue through
tonight. Snow and thus MVFR conditions are expected beginning
Monday morning, with conditions improving in the afternoon.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The strong front and embedded NW Gulf low will impact the N. Gulf
Coast and inner coastal waters this evening, then will quickly
subside as the front falls apart. Precipitation seems to be
remaining all snow for the coast except for near Cordova where
some mixing with rain may be expected. There is some possibility
of moisture making it over the mountains with weak isentropic
lift, once downslope flow ends, but dynamics are weak.

As the system slides eastward across the Gulf tonight, southwesterly
flow aloft over the Cook Inlet region resumes. The result will be
a weak deformation band that moves up the Inlet, bringing light
snow to the Kenai Peninsula. Confidence is increasing that the
deformation band makes it to the Anchorage and possibly even the
Mat-Su before fizzling out, with snow amounts expected generally
up to 2 inches.

Monday night into Tuesday the storm track stays out over the Gulf toward
the Yukon where most of our area stays in weak flow with embedded
shortwaves. The best chance of snow will thus remain toward the
eastern Prince William Sound and southeastern Copper River Basin.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
As the remnants of the front that made landfall along the Bristol
Bay coast early today continue to slowly weaken, widespread snow
will break up into showers over much of Bristol Bay this evening.
This will also allow showers to develop over eastern Bristol Bay
that have otherwise been dry due to downsloping as the strong
cross-barrier flow diminishes. By Monday an upper level trough
descending from the interior will merge with the Bering trough,
producing a broad upper level trough that will continue into
Tuesday. This trough will bring clouds and a chance of snow
showers to much of the area into mid-week. Most of these showers
should occur over Bristol Bay where the greatest moisture will be
present, though accumulations will be light throughout the area
with diminishing winds.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The hurricane force low that moved into the Bering on Saturday
will continue to weaken to below gale force by Monday morning as
it slowly moves through the Southern Bering. With persistent
gale-storm force winds, high seas from this system will continue
south of the chain into Monday morning. Behind the low, cold air
beginning to descend into the Western Bering is causing showers to
begin to switch over the snow. This trend will continue into
Monday and Tuesday as the low very slowly moves south of the
chain, spreading widespread snow showers throughout much of the
region. This system will move out of the area on Tuesday as winds
fall below gale force, which slightly slower than initially
expected.

&&

.LONG TERM FORECAST (Days 3 through 7)...
An active pattern will continue through the weekend and into early
next week with multiple lows traversing through the area. The
models are struggling with the placement, timing, and intensity of
these lows so ensemble guidance was used to avoid the extremes of
the deterministic runs. Until early next week there is some
agreement that the storm track will keep the heaviest
precipitation away from the mainland.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Storm...132 172 173 174 176  Gale...119 120 127 128 130
131 138 139 150 155 170 171 175 177.

&&

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