Gale Warning 1, NWS Anchorage, AK

855 
FZAK61 PAFC 011158
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
258 AM AKST Sun Jan 1 2023

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.

PKZ399-020145-
258 AM AKST Sun Jan 1 2023
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front moves over the North Gulf Coast Mon afternoon. A 956 mb 
low at 56N 156W moves to 58N 155W at 970 mb for Mon morning, then
moves over the Alaska Peninsula through Mon afternoon.

$$

PKZ351-020145-
Gulf of Alaska Offshore North of 57N and West of 144W-
258 AM AKST Sun Jan 1 2023

.TODAY...SE wind 15 to 25 kt. Seas 17 to 24 ft.
.TONIGHT...SE wind 15 to 30 kt. Seas 18 to 22 ft.
.MON...S wind 25 kt. Seas 16 to 20 ft.
.MON NIGHT...SE wind 10 to 20 kt. Seas 11 to 17 ft.
.TUE...E wind 25 to 40 kt. Seas 10 to 18 ft.
.WED...S wind 30 to 45 kt. Seas 12 to 20 ft.
.THU...NW wind 10 kt. Seas 4 to 7 ft.

$$

PKZ352-020145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
258 AM AKST Sun Jan 1 2023

.TODAY...S wind 15 to 25 kt. Seas 17 to 22 ft.
.TONIGHT...S wind 15 to 25 kt. Seas 17 to 21 ft.
.MON...S wind 10 to 25 kt. Seas 15 to 20 ft.
.MON NIGHT...SE wind up to 20 kt. Seas 10 to 16 ft.
.TUE...SE wind 10 to 25 kt. Seas 9 to 14 ft.
.WED...SW wind 10 to 20 kt. Seas 9 to 17 ft.
.THU...W wind 10 kt. Seas 4 to 7 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
556 AM AKST Sat Dec 31 2022

.ANALYSIS AND UPPER LEVELS...

Longwave pattern persists across much of Alaska, the Gulf of
Alaska, and the North Pacific through the weekend, embedded with
a series of lows and shortwaves. Satellite imagery is showing
multiple rotations, one between Kodiak Island and the Alaska
Peninsula, near the Pribilof Islands, and two south of the
Aleutian Islands. The surface low near Kodiak and the Pribilofs
are both weakening, their energy being absorbed by the low(s) in
the North Pacific. A front is lifting across the Gulf of Alaska
this weekend, aided by a subtropical jet who is guiding a swath of
moisture towards the north Gulf coast. A developing atmospheric
river that can be seen on the CIMMS Mimic satellite will push into
the Gulf and over Southcentral over the weekend, bringing the
next round of active weather to Southern Alaska.

&&

.MODEL DISCUSSION...

Model agreement continue to improve for the large complex system
south of the Aleutian Chain. There is also somewhat better
agreement with the progression of the front as it cross the Gulf
of Alaska towards the Southcentral coast. There remains
inconsistencies beyond 40 hours, which is typical as models tend
to struggle with pinpointing embedded lows within a complex system
like this. Models spread is still relatively large on Sunday
evening as the low crosses Kodiak Island and the Alaska Peninsula
towards the Bristol Bay area.

&&

.AVIATION...
PANC...VFR conditions will persist. Winds will gradually increase
through the afternoon hours, becoming gusty by this evening.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

Pretty quiet conditions this morning across Southcentral with
temperatures in the 20s and 30s across most locations, aside from
the Copper River Basin where temperatures are in the single digits
as of 5AM. A broad and elongated low remains in place across most
of southern Alaska, slowly tracking north, spreading a cloud shield
out ahead of it. This is telling of the next system to impact the
region beginning overnight tonight.

The elongated low's primary surface low is packing a punch, with
satellite imagery indicating some upper level instability and
lightning across it's southern reaches. This convection is not
expected to be drawn northward into Southcentral, however, as the
upper level jet folds and draws a southerly fetch into the Gulf of
Alaska, warmer temperatures aloft will overspread the region, and
an atmospheric river will take aim at southcentral. The good news
is that this is a fast moving pattern and the fold will quickly
disintegrate as it transitions east; but in the meantime, active
weather is in store for us beginning overnight tonight as these
warmer temperatures infiltrate the atmospheric column, bringing
areas of mixed precipitation Sunday, finally tapering off Monday.

Precipitation is expected to begin as snow except along the
coastlines, including in Kodiak Island, the southern Kenai
Peninsula and Prince William Sound as temperatures are already
warmer in these locations. Warmer air will finally make its way
inland tonight resulting in a wintry mix of snow and freezing
rain, eventually transitioning to all freezing rain across the
Anchorage Bowl, Matanuska Valley, western Kenai Peninsula and the
lower elevations of the Copper Basin, south of Copper Center. Cold
air is expected to make it's way back into the region MOnday,
with precipitation eventually transitioning to snow.

Lastly, as this system is paired with a folded jet and stronger
winds aloft, gusty surface winds are expected at the higher
elevations, along Portage Pass, Turnagain Pass, and the Matanuska
Valley. There are several Winter Weather Advisories and a Winter
Storm Watch issued for this upcoming system. Please refer to them
for further details.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...

This morning south of Unalaska there is a 955 mb low. This low is
going to track eastward this morning. A new low will form along
the frontal boundary south of Kodiak later today. By Sunday
morning that low will move across the Alaska Peninsula and into
Bristol Bay/southwest Alaska. On satellite imagery there is a
fetch of modified tropical air entrained into this system. This
system will bring a fresh batch of snow to Southwest AK. The
pressure gradient force is also strong with this system so expect
blowing snow add gales over Bristol Bay. The surface low will
wobble around Bristol Bay into Tuesday morning, but the low

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...

This morning south of Unalaska there is a 955 mb low. This low is
going to track eastward this morning. A new low will form along
the frontal boundary south of Kodiak later today. By Sunday
morning that low will move across the Alaska Peninsula and into
Bristol Bay and southwest Alaska. On satellite imagery (CIMSS
MIMIC PW) there is a discernible fetch of modified tropical air
entrained into this system. This system will bring snow to the
Alaska Peninsula, to the central and eastern Aleutians. Even
though this system has a tropical connection, there is fierce
cold air pushing across the Bering and over SW AK. Additionally,
freezing spray will develop as far south as the Pribilof Islands
this forecast period. On satellite imagery, the ice shield
continues to grow over portions of the north and eastern Bering
and near Egegik.

$$.LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)...

Going into the long term, the low forecast to bring this
weekend's active weather to southern mainland Alaska will have
weakened significantly, elongating along the Southwest coast and
across the Alaska Peninsula on Tuesday. By that point, mainly
only upslope precipitation will be lingering along the Gulf coast
as southerly flow continues to wrap around the weakening low.
Scattered, showery precipitation may also continue to be present
in Bristol Bay and along the Alaska Peninsula in the vicinity of
the decaying low. Any precipitation is likely to be all snow.
Elsewhere, inland locations will be mostly dry. Beyond Tuesday,
uncertainty increases, with large spread in the timing and track
of various features. One of the higher confidence features is a
potentially gale-force low entering the eastern Gulf of Alaska
Tuesday night and tracking toward the western Gulf coast by
Wednesday night. Several other lows look to take a similar track
following this one, however, models disagree on where the energy
is focused, meaning the strength of this feature is highly
uncertain. Its impacts, primarily another round of coastal
precipitation, are most likely to be focused between Kodiak
Island and the eastern Kenai Peninsula Wednesday into Wednesday
night. Some light overrunning precipitation may move into the
Cook Inlet region and Southwest Alaska, but it is likely to be all
snow. As the low weakens into Thursday, southern mainland Alaska
looks to dry out with weak flow and no major source of moisture
available, though some upslope shower activity may continue along
the coastal mountains.

Out west, northerly flow prevails across the central and eastern
Bering Sea at the beginning of the period, with scattered snow
showers moving into the Aleutians. In the western Bering, a large
upper-level low supported by a cold air mass moving out of East
Asia begins to encroach. It is led by a front, which appears to
bring mostly snow to the western and central Aleutians through
Tuesday night. The Pacific jet will retain a primarily zonal
orientation far south of the forecast area, meaning that as the
upper low slowly moves over the Bering/Aleutians, it will bring
with it many embedded hard to resolve, weak-to-moderate intensity
lows. This will keep relatively cold air in place and bring
periodic chances for snow reaching as far east as the eastern
Bering/Aleutians by Friday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Watch: 125
		 Winter Weather Advisory: 101 111 121 141 145
MARINE...Storm Warning: 119 120 130 131 139
		 Gale Warning: 125 128 132 136 137 138 140 150 160 351 352
		 Heavy Freezing Spray Warning: 180 185
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...KM
SOUTHCENTRAL ALASKA...AB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PJS
LONG TERM...CQ