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Sea Ice for Walrus Outlook

Overview of SIWO

The Sea Ice for Walrus Outlook (SIWO) is a resource for Alaska Native subsistence hunters, coastal communities, and others interested in sea ice and walrus. The SIWO provides weekly reports during the spring sea-ice season with information on weather and sea-ice conditions relevant to walrus in the northern Bering Sea and southern Chukchi Sea regions of Alaska.

The outlooks are produced with information on weather and sea-ice conditions provided by the National Weather Service Alaska Region and Alaska Native sea-ice experts. The SIWO is a collaborative network managed by the Arctic Research Consortium of the U.S. (ARCUS) and AOOS, in partnership with the Eskimo Walrus Commission, the National Weather Service, the University of Alaska Fairbanks, and local observers. 

Background photo courtesy of Clarence Irrigoo, Jr.

Sea Ice for Walrus Outlook - logo by R Erickson

Weekly Forecasts

The forecast season usually begins in March and runs through June, depending on sea ice conditions. The full Sea Ice for Walrus Outlook can be found on the ARCUS SIWO Facebook page. The weekly forecasts of surface currents and sea ice from AOOS will also be posted on this page during the current SIWO season.

SIWO Forecast – April 18, 2025

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus

Click the name of each community below to view more frequently updated and detailed information from the National Weather Service.

Synopsis: A low-pressure system over western Alaska and the Bering Sea will shift to the north through Saturday evening, bringing windy, blizzard conditions along the North Slope and will begin to dwindle off Friday evening. A low pressure will be following a slight ridge and will begin to impact the Y-K Delta Sunday morning by bringing mostly rain in, though some places will have snow or a mix of both. As this occurs, a high pressure will build on the North Slope, keeping the high temperatures in the low-to-mid double digits and the low temperatures in the negative single digits all week. A low pressure will be making its way across the Aleutian Islands Thursday morning and will impact the southern part of the Y-K Delta beginning Friday, bringing mixed precipitation and strong winds gusting as high as potentially 45 mph (40 kts). Southerly/southeasterly winds have the potential to pick up to 35 mph (30 kt) gusts in the western Arctic coast Tuesday afternoon and evening and go through the rest of the week.

Near St. Lawrence Island

Shorefast ice extends up to 7 miles (11 km) off the north shore and up to 3 miles (5 km) off the east shore. On the south side of the island, a large polynya extends beyond the shorefast ice and continues to fill in with new ice. Open water extends up to 11 mi (18 km), open ice pack extends up to 55 mi (88.5 km), and then close ice pack extends up to 155 mi (249 km). Otherwise, much of the mobile sea ice surrounding the island consists of very close to consolidated pack ice of big to giant floes.

Nome

Shorefast ice along the Nome coastline extends up to 1.5 mi (2.4 km) from the shoreline. A polynya extends up to 10 mi (16 km) beyond the shorefast ice. The remainder of the ice pack in the Nome region is close to very close pack ice consisting of big to giant floes.

Brevig Mission/Port Clarence Area

This area has not begun yet for the 2025 season. 

Wales to Shishmaref

Shorefast ice generally extends up to 15 mi (24 km) to 25 mi (40 km) from the Wales to Shishmaref coastline. The mobile ice pack beyond the shorefast ice is consolidated ice consisting of vast to giant floes.

Diomede

Shorefast ice extends between the islands. The mobile ice pack beyond the shorefast ice and surrounding the islands is consolidated ice consisting of vast to giant floes.

Forecast Discussion

Ice Forecast

Sea ice movement is expected to be minimal through Saturday (19 Apr) due to light and variable winds. From Sunday (20 Apr) through Tuesday (22 Apr), sea ice will generally drift south to southwest. Polynyas will likely fill in with new ice through the rest of the week during periods of light winds, and then polynyas will grow again when northerly to northeasterly winds increase early next week.

Wind Synopsis

Near St. Lawrence Island, winds will be fairly weak at roughly 5 mph (4 kts) out of the west Friday through Saturday afternoon, though there will be a shift where the winds will come out of the south Friday evening into Saturday. They have the potential to gust as high as 25 mph (22 kts) and shift to out of the east/northeast beginning as early as Sunday morning through Tuesday morning before coming back down to 10 mph (8 kts) and shifting northerly overnight Tuesday into Wednesday. They will come up again and potentially gust as high as 25 mph (22 kts) beginning Wednesday afternoon through Friday. They could shift again Wednesday afternoon and come from the northeast for the rest of the week.

Near Wales and Diomede, winds will be out of the west at roughly 8 mph (7 kts) during the day on Friday. Winds will then be coming out of the south at roughly 10 mph (8 kts) early Saturday through Sunday morning. Winds will pick up and shift then to easterly/northeasterly up to about 15 mph (13 kts) through Tuesday. They will become northerly Tuesday afternoon and may gust as high as 25 mph (22 kts) through the rest of the week.

Near Shishmaref, winds will be out of the northwest at about 15 mph (13 kts) through Friday afternoon. They will then shift to westerly/southwesterly and come down to roughly 5 mph (4 kts).They will become southerly Saturday afternoon through Sunday morning and shift again to easterly/northeasterly and come up to roughly 15 mph (13 kts) Sunday morning. Winds will then shift Tuesday afternoon to become more northerly and come down slightly to 10 mph (8 kts).

Near Nome, winds will be westerly/southwesterly at roughly 15 mph (13 kts) on Friday. They then shift to become more southerly and come down to roughly 5 mph (4 kts) Saturday morning and then become easterly by Saturday evening. Winds pick up again Sunday morning to gusts as high as 15 mph (13 kts) and become more northeasterly. They will come down again Monday afternoon to roughly 10 mph (8 kts). They will then become more northerly by Tuesday afternoon and back to northeasterly by Thursday afternoon through the rest of the week.

Temperature Trend

Near St. Lawrence Island, highs will remain in the mid-to-high 20s and lows in the teens through the week.

Near Wales and Diomede, highs will likely be in the 20s and lows in the single digits to lower double digits.

Near Shishmaref, highs are expected to be in the lower to mid 20s, and overnight lows in the single digits.

Near Nome, highs are expected to be in the upper 20s to lower 30s, with lows in the upper teens to lower 20s.

Daily Weather, Wind, and Temperature Updates

The National Weather Service provides twice-daily, text only updates on the weather, wind, and temperature conditions in specific geographical zones. An interactive weather map for access to other Alaskan zones can be found here: http://weather.gov/anchorage/ice

Higher resolution satellite images and wind maps (wind updated daily) can be viewed here: http://www.weather.gov/afg/SIWO_overview

The Alaska Ocean Observing System shares a variety of weather and sea ice related resources in their Bering Sea Portal at https://bering-sea.portal.aoos.org/.

NWS Sea Ice Forecast Maps

Marine forecast for the West Coast and Arctic Coast

Remote Sensing Images

NWS Bering Strait Region Satellite Image
NWS Wales to Shishmaref Area Satellite Image
St. Lawrence Island Area Satellite Image

Observations & Comments

Observations of Sea Ice Development

 

Observations from Gambell

Thursday, 17 April 2025 – Clarence Irrigoo, Jr.

21° NNE 7 mph, two boats went out and they got a walrus.

Sea ice and weather conditions in Gambell, AK.

Sea ice and weather conditions in Gambell. Photo courtesy of Clarence Irrigoo, Jr.

Observations from Savoonga

Thursday, 17 April 2025 – Aqef Waghiyi

Wind northwest at 10 knots, calm. Barometer 1005, humidity 85. Photos coming soon.

Sea ice and weather conditions in Gambell, AK.

Sea ice and weather conditions in Savoonga. Photos courtesy of Aqef Waghiyi.

Observations from Wales

Observation from Wales coming soon.

Observations from Wales

Thomas Farrugia of AOOS visited Nome for a training this week and shares these images of sea ice in the area.

Sea ice and weather conditions in Gambell, AK.
Sea ice and weather conditions in Gambell, AK.
Sea ice and weather conditions in Gambell, AK.
Sea ice and weather conditions in Gambell, AK.
Sea ice and weather conditions in Gambell, AK.
Sea ice and weather conditions in Gambell, AK.

Sea ice and weather conditions in Nome. Photos courtesy of Thomas Farrugia, AOOS.

Shared by the Alaska Ocean Observing System (AOOS) for 1–9 April 2025

The images below show animations of the movement of ice predicted by the HYbrid Coordinate Ocean Model (HYCOM). Snapshots from the forecast show ice coverage from 0% (black) to 100% (white) and arrows show the relative speed and direction of the ice. A light boundary is drawn at 15% predicted ice cover to highlight the ice edge, but ice may be predicted to extend beyond it. Some bays, lagoons, and areas very close to shore are not covered by the model. (Image produced by the Alaska Ocean Observing System / Axiom Data Science).

 

These animations show the predicted movement of ice predicted by the HYbrid Coordinate Ocean Model (HYCOM). Snapshots from the forecast show ice coverage from 0% (black) to 100% (white) and arrows show the relative speed and direction of the ice. A light boundary is drawn at 15% predicted ice cover to highlight the ice edge, but ice may be predicted to extend beyond it. Some bays, lagoons, and areas very close to shore are not covered by the model. (Image produced by the Alaska Ocean Observing System / Axiom Data Science)

SIWO Forecast Archives

SIWO Forecast – April 18, 2025

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus Click the name of each community below to view more frequently updated and detailed information from the National Weather Service. Synopsis: A low-pressure system over western Alaska...

SIWO Forecast – April 11, 2025

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus Click the name of each community below to view more frequently updated and detailed information from the National Weather Service. Synopsis: A cold low-pressure system over western...

SIWO Forecast – April 4, 2025

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus Click the name of each community below to view more frequently updated and detailed information from the National Weather Service. Synopsis: Broad high pressure continues over St....

SIWO Forecast – March 28, 2025

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus Click the name of each community below to view more frequently updated and detailed information from the National Weather Service. Synopsis: A ridge of high pressure that is currently...

SIWO Forecast – March 21, 2025

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus Click the name of each community below to view more frequently updated and detailed information from the National Weather Service. Synopsis: Generally quiet weather is expected for St....

SIWO Forecast – June 28, 2024

Assessment of Current Ice Conditions Relevant to Distribution and Access of Walrus Click the name of each community below to view more frequently updated and detailed information from the National Weather Service. Synopsis: Low pressure lingers over the Bering Sea...

Sea Ice for Walrus Outlook releases short film

The Sea Ice for Walrus Outlook (SIWO) announced the release of a new short film highlighting the collaboration and dedication of the many contributors who have shaped the program’s success as it approaches its 15th season. SIWO provides weekly updates during the...