FZAK30 PAFC 222019 ICOAFC Sea Ice Outlook for Western and Arctic Alaskan Coastal Waters National Weather Service Anchorage Alaska 1219 PM AKDT Tuesday 22 October 2024 ...OCTOBER 2024 MONTHLY SEA ICE OUTLOOK... The Arctic sea ice minimum was reached during September and new sea ice has begun to grow, albeit slowly during the past month. New sea ice has also begun to form along the north and west coasts of Alaska, though mainly contained to the shallow and protected areas through mid-October. While sea ice growth has been slow in the Beaufort Sea, the Chukchi Sea is actually ahead of recent years after sea ice remained through the melt season even along the northern Chukchi Peninsula coast. As we look forward into the first few months of freeze-up season, La Nina conditions are still expected to develop by winter. With the lingering ice in the Chukchi Sea and if storm tracks stay south as is typical during La Nina winters, we could see freeze-up conditions similar to the past couple years or a bit faster. Freeze-up within the Beaufort Sea will likely continue to be a bit slower than recent years. Detailed information can be found in each pertinent section below. …FREEZE-UP OUTLOOK FOR THE BEAUFORT SEA… Along the north coast of Alaska, seven tenths coverage of sea ice beyond barrier islands up to 20 nm offshore is expected during the first week of November. The main ice pack is expected to begin merging with the new sea ice off the Alaska coastline during the second week of November, though it may not occur until the third week of November if the current trends continue. …FREEZE-UP OUTLOOK FOR THE CHUKCHI SEA… Along the coast from Icy Cape to Point Barrow, sea ice is expected to reach seven tenths concentration around mid-November. For navigational waters around Utqiagvik, seven tenths concentration is expected around mid-November. For Icy Cape to Utqiagvik to 170W, seven tenths coverage is expected during the last week of November or first week of December. For navigational waters from Point Hope to Icy Cape, three tenths coverage is expected during the first week of November. Seven tenths coverage is expected around mid-November. For the Chukchi Sea, Utqiagvik to 75N and 170W, seven tenths coverage is expected around mid-November. In Kotzebue Sound, three tenths coverage is expected during the first week of November, with seven tenths coverage expected during the third week of November. For navigational waters of Cape Krusenstern to Point Hope, the first ice widely varies from year to year from October through November based on weather patterns but is more likely during the third week of November this year. Seven tenths concentration is expected by the end of November. From Wales to Espenberg, sea ice is expected to reach three tenths coverage within navigational waters by mid-November. Seven tenths coverage through navigational waters is expected during the last week of November. For Wales to Point Hope to 170W, three tenths coverage is expected during the last week of November. Seven tenths coverage is expected during the first half of December. The Bering Strait is expected to reach seven tenths within 20 nm of the center line during the first half of December. …FREEZE-UP OUTLOOK FOR THE BERING SEA… Within Norton Sound, the first sea ice has begun to form within Norton Bay and Golovin Bay. Three tenths coverage within the main sound is expected during the second week of November, and seven tenths coverage is expected during the last week of November. Along the Yukon River Delta, three tenths coverage is expected by mid-November with seven tenths coverage likely during the 3rd or 4th week of November. Along the Kuskokwim River Delta, the first sea ice formation is expected by the end of October. Three tenths coverage is expected during the third week of November and seven tenths coverage is expected by the end of November. For Bristol Bay, the first new sea ice varies year to year based on how quickly arctic air sets up over the area, from late October into December. The first new ice formation is expected by the end of November. Three tenths concentration is expected during the first half of December and seven tenths concentration throughout the Bay is expected during the first half of January. The main ice edge is expected to reach Saint Lawrence Island during the second half of December. Coastal ice is expected to extend west of Nunivak Island around mid- December. …FREEZE-UP OUTLOOK FOR COOK INLET… In general, sea ice in Cook Inlet is highly dependent on the timing of when the first arctic air mass sets up overhead. Knik Arm is usually the first area to freeze, which is likely during November. An early deep cold snap could lead to an early freeze-up. In addition, the expected transition back to La Nina conditions could lead to freeze up in the Upper Inlet in the second half of November, similar to the 2020-2023 ice seasons. The first ice north of the line from Susitna Delta to Pt. Possession is expected during the first half of November. The first ice south of the line from Susitna Delta to Pt. Possession is expected during the second half of November. The first ice south of The Forelands is expected during the first half of December. North of the Forelands, three tenths concentration is expected during the first half of December. Seven tenths concentration is expected during the second half of December. The first ice along the coast from Kenai to Nikiski is expected during the second half of December. The ice edge may make it to Kalgin Island by the end of December. This will be highly dependent on the air temperatures throughout the late fall. From 60N to the Forelands, sea ice is expected to reach three tenths concentration during the fourth week of December, though it could be delayed until the first week of January. Sea ice is expected to make it to Ninilchik during the first half of January. $$ Schreck