Gale Warning 672, NWS Anchorage, AK

995 
FZAK61 PAFC 201208
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
308 AM AKST SUN NOV 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.

PKZ399-210200-
308 AM AKST SUN NOV 20 2016
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A FRONT WILL MOVE INTO THE NORTH GULF COAST AND BECOME NEARLY
STATIONARY THROUGH MON AFTERNOON. A 986 MB LOW AT 54N 154W WILL
MOVE TO 56N 153W AT 976 MB THIS AFTERNOON AND THEN TO 53N 154W
LATE TONIGHT. A NEW 987 MB LOW MOVES TO 57N 144W LATE MON NIGHT.
$$

PKZ351-210200-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W-
308 AM AKST SUN NOV 20 2016

.TODAY...SE WIND 10 TO 25 KT INCREASING TO 20 TO 30 KT IN THE
AFTERNOON. SEAS 6 TO 9 FT. RAIN.
.TONIGHT...SE WIND 15 TO 30 KT. SEAS 8 TO 11 FT. RAIN.
.MON...E WIND 15 TO 30 KT. SEAS 8 TO 13 FT. RAIN.
.MON NIGHT...NE WIND 20 TO 35 KT. SEAS 9 TO 17 FT.
.TUE THROUGH WED...NE WIND 15 TO 30 KT. SEAS 8 TO 13 FT.
.THU...SE WIND UP TO 20 KT. SEAS 7 TO 10 FT.

$$

PKZ352-210200-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W-
308 AM AKST SUN NOV 20 2016

.TODAY...S WIND 25 KT. SEAS 7 TO 10 FT. RAIN.
.TONIGHT...SE WIND 10 TO 20 KT. SEAS 8 TO 12 FT. RAIN.
.MON...E WIND 10 TO 15 KT. SEAS 9 FT.
.MON NIGHT...N WIND UP TO 20 KT. SEAS 8 TO 11 FT.
.TUE THROUGH WED...NE WIND 10 TO 25 KT. SEAS 8 TO 13 FT.
.THU...SE WIND 10 TO 25 KT. SEAS 7 TO 12 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
328 PM AKST Sat Nov 19 2016

.ANALYSIS AND UPPER LEVELS...
A broad upper level trough extends from the Kamchatka Peninsula
to over the North Pacific. A fairly active jet stream extends east
from Asia to south of the Ak Pen and is supporting a couple of low
pressure systems near the central and eastern Aleutians. The
center near the eastern Aleutians and associated front has a more
favorable jet position for further development. A weak short wave
extends southeast across the mainland with a weak closed upper low
over the Kenai Peninsula and supports a broad low pressure trough
over the northern Gulf.

Scattered showers, associated with the broad upper trough, are
evident across much of the north Gulf Coast and portions of the
Kenai peninsula. Low stratus continues across much of the Copper
River Basin with variable cloud cover elsewhere across
Southcentral. Gusty northerly gap flows continued through Thompson
pass as well as northern Prince William sound. Areas of light
snow which fell this morning over the Delta has been replaced
with areas of stratus and fog with subsidence behind the upper
level trough. Stratus and fog was also evident over eastern
Bristol Bay, but was showing signs of dissipating this afternoon.
Much of the Bering Sea and ALeutians are under the influence of
several low pressure systems and experiences bouts of gusty winds
and rain and rain showers.

&&

.MODEL DISCUSSION...
Despite three merging systems over the Aleutian and northern
Pacific, guidance is in good agreement with the interactions and
general synoptics. Little change is expected in the western
domain grids (forecast) from the morning run. In the eastern
domain, the NAM/GFS look the best and will be used to make
adjustments to current grid package.

&&

.AVIATION...
VFR ceiling and visibilities overall. On Sunday afternoon there
is a chance of some snow over/near Anchorage. The probability is
less than 50 percent and thus VFR conditions seem likely, but VCSH
was put in to indicate a chance of lower conditions.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A tight vort max is currently centered over the Kenai Peninsula,
and will continue to track northward and weaken over the Susitna
Valley tonight. The Anchorage sounding this afternoon continues
to show a fairly dry air mass but with steep lapse rates, keeping
much of the Anchorage area and Southcentral interior dry through
tonight, with widely scattered showers persisting along the
northern gulf coast and Prince William Sound areas. A second
weaker wave will quickly push across Southcentral from the western
Gulf this evening, which will help to reinforce steady showers
along the north Gulf coast Tonight into Sunday morning.

A series of fronts associated with a North Pacific low to the west
will begin to push into the southern Gulf of Alaska and track
northward late tonight through Monday. This will usher in more
widespread precipitation and gusty winds across much of
Southcentral through Monday, as well as some warmer temperatures
and mixed precipitation types along the Eastern Kenai Peninsula.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...
Offshore flow will strengthen tonight in response to a storm
system passing to the south. This should help clear out most of
the stratus and patchy fog in Southwest and will keep temperatures
from dropping as much as last night. A little bit of snow may
make it across the Alaska Peninsula and affect portions of the
Alaska Peninsula south of Pilot Point, though most of it may
evaporate as the northerly flow provides a continuous supply of
cold and dry air near the surface. As this storm continues
eastward to the Gulf of Alaska there will be a chance of clouds
and snow pushing back westward across the Aleutian/Alaska Ranges,
especially on Monday. Have introduced chance PoPs for now.
Otherwise...expect cold, dry and fairly windy conditions to
persist for the next few days.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...
A strong and persistent jet stream centered just south of the
Aleutians will maintain active weather across the Bering Sea,
Aleutians, and southern Alaska Peninsula. Have upped winds to
storm force over a portion of the Central Aleutians near Adak
Tonight into Sunday as a ridge builds upstream and arctic air
advects southward, with unstable conditions likely to mix down
stronger winds from aloft. As the current system exits toward the
Gulf Sunday another will quickly enter from the west and drive
eastward across the region Sunday Night through Monday Night.
The associated weather looks very typical for this time of year,
with widespread gales and rapidly changing conditions as these
storms move through. Temps are just warm enough to keep precip-
type mostly rain, though snow showers will dominate in the colder
air behind systems.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The active pattern will continue through next week with multiple
lows moving across the forecast area. However, the storm track
looks to largely stay south of mainland Alaska with lows moving
across the Aleutians and then into the Gulf. This setup will keep
most of the precipitation and warm air out of the mainland with
coastal areas seeing the majority of the precipitation. Although
the models disagree somewhat on the timing of the various lows,
they are in decent agreement with the position of the storm track.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Storm Warning 176 177.
 Gale Warning 119 130 138 139 150 155 165 172 175 178 180.

&&

SYNOPSIS AND MODEL DISCUSSION...RC
SOUTHCENTRAL ALASKA...Pepe
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SB
LONG TERM...DK