####018006909#### FZAK30 PAFC 262303 RRA ICOAFC Sea Ice Outlook for Western and Arctic Alaskan Coastal Waters National Weather Service Anchorage Alaska 303 PM AKDT Thursday 26 October 2023 ...OCTOBER 2023 MONTHLY SEA ICE OUTLOOK… While freeze-up officially started in late September, there was more significant advancement especially in the Chukchi Sea during October. While the timing of new sea ice growth along the north coast of Alaska average, sea ice growth within shallow and protected waters along the west coast of Alaska was about one to two weeks earlier than last year. Looking farther into freeze-up, El Nino conditions look to persist through the coming winter and likely into spring 2024. Overall freeze-up looks like it will be faster than last year across Alaska waters and slower than last year over the western Bering Sea. Storm tracks during El Nino can bring some storms north into and through the Bering Sea, so it may be a season of variable sea ice conditions, though longer range sea ice guidance does indicate a slightly above average sea ice extent in January. Detailed information can be found in each pertinent section below. …FREEZE-UP OUTLOOK FOR THE BEAUFORT SEA… Sea ice concentration within 20 nm of the north coast of Alaska is expected to reach seven tenths by the end of October. The main ice pack will likely merge with the new ice along the Alaska coast during the last week of October or first week of November. …FREEZE-UP OUTLOOK FOR THE CHUKCHI SEA… Navigational waters around Point Barrow are expected to reach seven tenths concentration during the last week of October. For Icy Cape to Utqiagvik west to 170W, the first new sea ice is expected during the last week of October or first week of November. This area is expected to reach seven tenths concentration during the third week of November. From Point Hope to Icy Cape, the timing of freeze-up varies by several weeks from season to season. At this time, sea ice reaching 3 tenths concentration is expected during the first week of November and seven tenths coverage is expected during the third week of November. The area from Point Barrow to 75N and west to 170W is expected to reach seven tenths during the fourth week of November. Within Kotzebue Sound, three tenths coverage is expected during the first week of November, and seven tenths near mid-November. For Cape Krusenstern to Point Hope to 20 nm offshore, the first ice is expected during the first week of November. Seven tenths coverage is expected during the third week of November. For Wales to Espenberg to 20 nm offshore, three tenths concentration beyond barrier islands is expected around mid-November and seven tenths coverage is expected during the third week of November. For Wales to Point Hope to 170W three tenths coverage ice is expected during the third week of November. Seven tenths coverage is expected during the last week of November. For the Bering Strait within 20 nm of Center Line, seven tenths coverage is possible during the fourth week of November. …FREEZE-UP OUTLOOK FOR THE BERING SEA… For Norton Sound, sea ice has begun forming within Norton Bay, Golovin Bay, and some other shallow and protected areas of northern Norton Sound. The main area of Norton Sound is expected to reach three tenths concentration of sea ice during the second week of November. Seven tenths coverage is expected during the third or fourth week of November. For the Yukon-Kuskokwim Delta out to 20 nm offshore, three tenths coverage is expected during the first week of November and seven tenths coverage around mid-November. Sea ice is expected to extend beyond Nunivak Island during the third or fourth week of November. The first ice in Bristol Bay varies from year to year depending on the prevailing weather and temperature patterns. The first ice is expected during the second week of November but may be as late as early December if the main storm track is north into the Bering Sea through November. Three tenths coverage is likely in the first half of December and seven tenths coverage is likely in the second half of December. The ice edge is expected to reach Saint Lawrence Island during the last week of November. The ice edge is expected to reach Saint Matthew Island during the first half of January. At this time, there looks to be a 60 to 70 percent chance that the ice edge will reach Saint Paul Island this season. If it does, it will most likely be after January. …FREEZE-UP OUTLOOK FOR COOK INLET… Ice in Cook Inlet is very dependent on the prevailing ambient air temperature. The transition to El Nino conditions may shift freeze- up later from what has been seen during the last few years that have been in La Nina conditions. Around 75% of El Nino analog years result in a weather pattern that favors an upper level low pressure south of the Alaska Peninsula in the northeastern Pacific Ocean. If this pattern comes to fruition, the prevailing storm track will be one that brings warmer air to the region, as well as Chinook wind conditions which will drastically affect sea ice in the Cook Inlet area, preventing long periods of arctic air and sea ice getting established. In contrast, the La Nina conditions of the last 2-3 years has allowed for early season arctic air to become established without much displacement. Some ice has been observed near the mouth of the Knik River as well as on the mud flats of Turnagain Arm. Outside of these areas, the first ice north of the line from Susitna Delta to Point Possession is expected during the first week of November. The first ice south of the line from Susitna Delta to Point Possession to the Forelands is expected during the third week of November. The first ice south of the Forelands is expected during the first week of December. North of the Forelands, three tenths ice coverage is expected during the first week of December. Seven tenths coverage is expected during the second half of December. The first ice along the coast from Kenai to Nikiski is expected during the first half of January. The ice edge is expected to reach Kalgin Island during the second half of January. From 60N to the Forelands, three tenths concentration is expected during the first half of January. Seven tenths concentration is expected around mid-January. Sea ice may reach Ninilchik during the second half of January. If sea ice reaches Anchor Point, it will most likely be during the second half of January or first half of February. $$ Schreck