Gale Warning 295, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
445 AM AKDT Wed Mar 30 2022

.ANALYSIS AND UPPER LEVELS...

An upper trough extends northwest from the Panhandle through
Southcentral while an amplified upper ridge runs from the western
Gulf across the Southwest Coast this morning. Over the Bering, an
upper low just slightly north of Shemya is linked to a broad
frontal system moving across the Bering and the eastern Aleutians
today. Steady light snow continues over the Pribilofs while
intermittent light rain and snow mixed passes through the Southwest
Coast. Steady light rain continues over the most western tip of
the Alaska Peninsula including Cold Bay and Sand Point. Overnight
temperatures for both Southcentral and Southwest ranged from the
lower 20s to mid 30s, and in the mid to upper 30s for the
Aleutians.

&&

.MODEL DISCUSSION...

Models continue to remain in close agreement through Fri evening
until GFS pulls away from the rest of the solutions starting Fri
night into Sat morning. GEM and ECMWF shows similar progress for
the expected synoptic low over the Gulf which may direct gales
farther south and east of the forecast waters this weekend.
Meanwhile, GFS invites gales into the northern Gulf by Sat
morning. These differences will impact the timing for potential
gales over the marine zones including the timing of heavier
precipitation along the coast. For this reason, the uncertainties
among the models will be closely monitored for future updates.

&&

.AVIATION...

PANC...VFR conditions and light winds will persist. Though
satellite and weather observations from near Ted Stevens
International Airport indicated 7,000 ft ceilings overnight, the
potential for fog is low this morning.

&&

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

High pressure is over Southcentral Alaska today bringing in some
partial clearing. While there is enough residual moisture to keep
the clearing only partial, it is also keeping fog from developing
across the region as well. Expect some sunny periods across
Southcentral today especially in the afternoon, though some
cumulus clouds may develop over the mountains due to the air
aloft still being cold.

The next front is moving into the Kodiak area from the southwest
today and will likely bring rain to Kodiak City in the afternoon
with areas south of there getting rain moving in sooner. The ridge
over Southcentral Alaska will help to slow this front as a
developing low in the north Pacific will move along it and then
move into the Gulf on Thursday. What that will mean is an
extended period of rainfall for Kodiak Island with precipitation
not making it very far inland across the coastal mountains along
the Gulf coast. A barrier jet will also develop along the north
Gulf coast and could bring winds up to storm force neat the Barren
Islands on Thursday with widespread Gales in the marine waters.

By Friday the low and front will have weakened, leaving the
residual moisture and weak lifting mostly due to cold air aloft.
This will result in mostly clouds skies over the area with some
scattered rain and snow showers along the coast.

&&

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

Weak upper flow is leading to quiet conditions across much of the
region this morning. Mostly cloudy skies are seen along the coast,
with clearing farther inland. A front is currently tracking across
the eastern Bering and will move onshore by this evening. Strong,
deep southerly flow aloft will allow for mostly all rain in the
Bristol Bay area and mixing farther north, even into the overnight
hours. Given the orientation of the flow, locations in the lee of
the Alaska Range and Kuskokwim Mountains will remain mostly dry
with downsloping. Much of the precipitation will not reach
interior areas. As the front's parent low shifts westward in the
Bering, another low will approach Kodiak Island on Thursday.
Consequently, both of these features will cause the main
precipitation field to shift closer to the immediate coastline.
Temperatures in the morning should be cold enough for around an
inch of slushy snowfall, particularly for the Bristol Bay coast,
but will quickly transition to all rain for many areas into the
afternoon with highs near 40. Drier conditions are expected by
Friday as the low becomes vertically stacked and weakens, with the
main area of precipitation again moving offshore and downsloping
occurring north of the Alaska Range. Gusty easterly winds will be
possible between Dillingham and King Salmon at this time as well.

&&

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

A front tracking across the eastern Bering is bringing rain and
gusty southerly winds for areas generally east of Unimak Pass.
Conditions will improve through the morning as the front departs.
A broad upper low encompassing nearly the entire Bering, and a
series of shortwaves pivoting around its center will persist
through Thursday. Scattered rain/snow showers will continue, but
will not be impactful. A deeper upper trough will move into the
western Bering by Friday evening, leading to more widespread
showers into the weekend.

&&

.MARINE (Days 3 through 5 - Friday through Sunday)...

Gulf of Alaska - A weakening low moves across Kodiak Island and
the Alaska Peninsula as its front extends to a second low in the
Eastern Gulf through Sunday. Forecast confidence is mixed, due to
the tracks of the lows. High end gales wrap the low - from the
Northeast through Cook Inlet, Kamishak Bay and the Barren Islands,
and from the South in the Gulf east of Kodiak Island, diminishing
Saturday. Gusty Easterly winds continue over the Gulf through
Sunday. Seas to 18 feet over the Gulf and Shelikof Strait for
Friday, and to 13 feet over Kamishak Bay, subsiding.

Bering - A Western Bering low moves to the Central Bering, and a
Bristol Bay low moves near Nunivak Island for Sunday. A front
extends across the Bering between the two lows. A North Pacific
low deepens as it moves East to the South of the Aleutians through
Sunday. Forecast confidence is mixed with the timing of the lows.
high end Northeasterly gales over Bristol Bay diminish Saturday.
Seas less than 10 feet. Winds increase to high end gales over the
Aleutians and Southern Bering for Sunday. Seas building to 18 feet
along the Pacific side of the Aleutians by Sunday.

&&

.Long Term Discussion (Days 4 through 7: Saturday through
Tuesday)...

Looking ahead in the extended forecast, the latest operational
model runs are in decent agreement with the evolution and
progression of the synoptic scale features, but begin to diverge
in the specific details towards the end of the period. The pattern
remains amplified with a broad trough over the Bering
Sea/Aleutian Islands, extending eastward across the Gulf and over
Southcentral Alaska. A surface low near the Alaska Peninsula
dissipates on Saturday, while the associated front stalls out
along the north gulf coast. Meanwhile, a couple of stronger
systems tracks along the Aleutians into the Gulf during the
weekend into early next week. Even though there is a good amount
of uncertainty with these systems, most of the precipitation will
be concentrated through the Panhandle and up into the southern
coasts. Much of the mainland should be relatively dry during the
period, with the exception for potential snow in the mountains and
colder inland areas. Out west, an active storm pattern associated
with the aforementioned broad trough will maintain showery
conditions and gusty winds for much across the Bering and
Aleutians into early next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...GALE WARNING: 120 130-132 138 160 176 178 180 351 352 411.

&&

SYNOPSIS AND MODEL DISCUSSION...CB
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...AP
MARINE/LONG TERM...MK/MF