124
FZAK80 PAFC 042221
ICEAFC

Sea Ice Forecast for Western and Arctic Alaskan Coastal Waters
National Weather Service - Alaska Sea Ice Program
121 PM AKST Wednesday 4 December 2024


FORECAST VALID...Monday 9 December 2024

ANALYSIS CONFIDENCE...Moderate

SYNOPSIS...High pressure will persist across the Chukchi and
Beaufort Seas through Monday. The storm track remains from the north
Pacific Ocean into the Gulf of Alaska through early Saturday.
Saturday into Sunday, a large and deep low pressure will track into
the eastern Bering Sea.

-BEAUFORT SEA-

PKZ505-Central US Arctic Offshore-
PKZ510-Eastern US Arctic Offshore-
PKZ813-Point Franklin to Cape Halkett out to 15 nm-
PKZ814-Cape Halkett to Flaxman Island out to 15 nm-
PKZ815-Flaxman Island to Demarcation Point out to 15 nm-
PKZ859-Point Franklin to Cape Halkett from 15 to 75 nm-
PKZ860-Cape Halkett to Flaxman Island from 15 to 80 nm-
PKZ861-Flaxman Island to Demarcation Point from 15 to 75 nm-

Ice covered.

FORECAST FOR THE BEAUFORT SEA (DAYS 1 through 5)...Forecast
confidence is high. Winds will be northeasterly through the period,
turning more easterly on Monday. Expect pack ice to move with the
Beaufort Gyre to the west around 10-15 nm/day through Saturday.
Expect a shear zone to form between the growing shorefast ice and
the rest of the pack. Thickening ice conditions will persist through
Monday.

-CHUKCHI SEA-

PKZ500-Western US Arctic Offshore-
PKZ505-Central US Arctic Offshore-
PKZ808-Cape Espenberg to Motherwood Point out to 10 nm-
PKZ809- Motherwood Point to Cape Krusenstern out to 10 nm-
PKZ811-Cape Thompson to Cape Beaufort out to 15 nm-
PKZ812-Cape Beaufort to Point Franklin out to 15 nm-
PKZ813-Point Franklin to Cape Halkett out to 15 nm-
PKZ855-Kotzebue Sound greater than 10 nm-
PKZ857-Cape Thompson to Cape Beaufort from 15 to 85 nm-
PKZ858-Cape Beaufort to Point Franklin from 15 to 85 nm-
PKZ859-Point Franklin to Cape Halkett from 15 to 75 nm-
PKZ807-Wales to Cape Espenberg out to 15 nm-
PKZ810-Cape Krusenstern to Cape Thompson out to 15 nm-
PKZ856-Wales to Cape Thompson greater than 15 nm-

Ice covered.

FORECAST FOR THE CHUKCHI SEA (DAYS 1 through 5)...Forecast
confidence is high. Light to moderate northerly winds will persist
through early Saturday then turn more easterly through Monday. Ice
will continue to advect southward around 10 nm/day through Friday.
When the winds turn more easterly on Monday, expect large polynyas
to form along west facing coastlines, especially from Utqiagvik
through Cape Lisburne. Any shorefast ice in this area will be
vulnerable to break off. Thickening ice conditions will persist
through Saturday before a pause due to stronger winds and a warmer
air mass overhead.

-BERING SEA-

PKZ801-Etolin Strait to Dall Point out to 15 nm-
PKZ802-Dall Point to Kwikpak Pass out to 15 nm-
PKZ803-Kwikpak Pass to Cape Stephens out to 15 nm-
PKZ804-Cape Stephens to Moses Point out to 15 nm-
PKZ805-Moses Point to Sledge Island out to 15 nm-

Ice covered.

PKZ760-Bristol Bay greater than 15 nm-
PKZ761-Bristol Bay from Port Heiden to Cape Chichagof out to 15 nm-
PKZ762-Bristol Bay from Cape Chichagof to Cape Peirce out to 15 nm-
PKZ763-Kuskokwim Delta and Etolin Strait out to 15 nm-
PKZ764-Kuskokwim Delta from 15 to 80 nm-
PKZ806-Sledge Island to Wales out to 15 nm-
PKZ816-South side of Saint Lawrence Island out to 15 nm-
PKZ817-North side of Saint Lawrence Island out to 15 nm-
PKZ850-Etolin Strait to Kwemeluk Pass from 15 to 90 nm-
PKZ852-Norton Sound greater than 15 nm-
PKZ853-Kwemeluk Pass to Kwikpak Pass from 15 to 90 nm-
PKZ854-Sledge Island to Wales greater than 15 nm-


In the Bering Sea, the ice edge extends from near Pilot Point to 59
36N 167 33W to 65 47N 169 14W and continues southwest in Russian
waters. The ice edge is open water.

From land-based points in Alaska, the ice edge extends from near
Pilot Point to 35 nm south of Cape Mohican to 7 nm west of Diomede
and continues southwest in Russian waters. The ice edge is open
water.

FORECAST FOR THE BERING SEA (DAYS 1 through 5)...Forecast confidence
is low to moderate. The storm track to the east of Bristol Bay, then
into the Bering Sea will pause growth first in the Bristol Bay area
through the period, then for most of the Bering Sea on Monday as a
large system moves into the eastern Bering Sea along with a warmer
air mass. Light to moderate northeasterly winds will advance the ice
edge to the west/southwest from the Bering Strait through Norton
Sound to the Yukon Delta. Expect the ice edge to expand around 10-15
nm/day, reaching Saint Lawrence Island in the next 24-48 hours.
Stronger easterly winds on Monday will continue the ice edge moving
westward, opening a large polynya along eastern Norton Sound. The
warmer air accompanying the system will likely melt some of the
newly formed ice in the area.

For the Kuskokwim Delta and Bristol Bay, growth will stall for the
remainder of the week with lighter winds and slightly warmer air
mass. For the weekend into early next week, expect a large retreat,
more so for Bristol Bay as easterly and southerly winds affect the
coast.



-COOK INLET-

PKZ740-Cook Inlet North of Kalgin Island-

SYNOPSISThe storm track moving from the northeastern Pacific Ocean
into the Gulf of Alaska will bring a warmer air mass over the Cook
Inlet region. A stronger system moving into the eastern Bering Sea
continues this trend.

The main ice edge extends from the East Foreland to the West
Foreland. The majority of ice in the upper Inlet runs right along
the coast from the East Foreland to Turnagain Arm.


FORECAST FOR COOK INLET (DAYS 1 through 5)...Forecast confidence is
high. Warmer air overhead will continue to stall growth and melt
existing ice. With lighter northerly winds expect ice to continue to
come out of Turnagain Arm and Knik Arm in belts and strips to be
moved southward in the upper Inlet. Stronger easterly winds through
Turnagain Arm on Monday will accelerate the melting trend.


&&
Lawson