FZAK30 PAFC 262036 ICOAFC Sea Ice Outlook for Western and Arctic Alaskan Coastal Waters National Weather Service Anchorage Alaska 1136 AM AKST Thursday 26 November 2020 ...NOVEMBER 2020 MONTHLY SEA ICE OUTLOOK... Looking at the big picture, the biggest change in the ice pack within Alaska waters in November is the sea ice growth within the Chukchi Sea. The sea ice extent in the Chukchi Sea has caught up to and now surpassed the extent in 2019, however it is still far behind historical averages. Sea ice along the west coast of Alaska has been very slow to form in November, however Cook Inlet has seen some sea ice growth the earliest we have seen since the 2012 to 2013 winter. As we look forward in the freeze-up season through February, there is high confidence that La Nina conditions will continue. Overall we expect that the western Bering sea may struggle the most to establish and thicken sea ice as the coldest air is expected to remain over the eastern Bering Sea and the Alaska mainland. Areas such as Bristol Bay and the Bering Sea side of the Alaska Peninsula may see extensive sea ice cover persist through winter once it can become established. However, it is important to note that while the general storm track and warmest air is expected to stay over the western Bering Sea and south of the Aleutian Islands, there could still be a few storms that track farther east through the Bering Sea. Cook Inlet sea ice is also expected to be more extensive than average. Confidence is highest in this area for below-normal atmospheric temperatures to persist as the signal for below-normal temperatures only strengthens in the later part of winter in long- range models. Detailed information can be found in each pertinent section below. ...FREEZE-UP OUTLOOK FOR THE CHUKCHI SEA… For Icy Cape to Utqiagvik, seven tenths concentration is expected by the end of November. For Icy Cape to Utqiagvik Offshore west to 170W the first new ice beyond navigational waters is expected during the first week of December. Seven tenths concentration is expected during the second week of December. This area is expected to be ice covered during the third week of December. For navigational waters from Cape Krusenstern to Point Hope, seven tenths coverage is expected by the end of November. For Wales to Espenberg to 20nm offshore, sea ice concentrations are expected to reach seven tenths by the second week of December. For Wales to Point Hope outside Kotzebue Sound to 170W, seven tenths concentration is expected during the second week of December. The Bering Strait is expected to have 7 tenths concentration of sea ice within 20 nm of the center line during the third week of December. ...FREEZE-UP OUTLOOK FOR THE BERING SEA... For Norton Sound, seven tenths coverage is expected to be reached by the first week of December. Along the Yukon River Delta, three tenths concentration is expected during the last week of November and 7 tenths concentration is expected during the first week of December. Along the Kuskokwim River Delta, three tenths concentration is expected during the last week of November and seven tenths coverage is expected during the first week of December. For Bristol Bay, we have seen some river ice exiting into the bay during cold snaps in November but sea ice has not yet begun growing. It is possible that we will see some new sea ice growth within Bristol Bay before the end of November, but confidence is higher that it will be during the first week of December. Three tenths coverage is expected by the last week of December. Seven tenths coverage is expected by the first week of January. The ice edge is expected to reach Saint Lawrence Island by the middle of January. The coastal sea ice is expected to extend beyond Nunivak Island during the first half of January. The ice edge is expected to reach Saint Matthew Island by the end of January. At this time there is a 50 to 75 percent chance that sea ice will reach Saint Paul Island this winter, however if it does it would most likely be in March or April. At this time there is a 25 to 50 percent chance that sea ice will reach Saint George Island this winter. If it does, it would most likely be in March or April. Along the Alaska Peninsula, coastal sea ice may reach Port Moller at the very end of January or first half of February. ...FREEZE-UP OUTLOOK FOR COOK INLET... Freeze-up has begun in upper Cook Inlet as well as some of the more protected bays of western lower Cook Inlet. This year, La Nina conditions are expected to continue to strengthen into the winter months, resulting in below average temperatures in general throughout Southcentral Alaska. With sea ice in Cook Inlet being closely tied to atmospheric temperatures in the region, sea ice formation is expected to continue to be earlier than the past few years as the ice edge advances southward. Overall sea ice extent may be similar to last winter as storm tracks are expected to generally remain south of the Cook Inlet region. Detailed information can be found in each pertinent section below. North of the Forelands, sea ice concentration is expected to reach 3 tenths during the first or second week of December, depending when air temperatures in the single digits and teens return to the area. Sea ice concentrations are expected to reach 7 tenths by the third week December. The first sea ice formation along the coast from Kenai to Nikiski is expected to form by the middle of December. The ice edge may reach Kalgin Island by the last week of December. For 60N to the Forelands, greater than three tenths coverage is expected during the first or second week of January. Seven tenths coverage is expected by the end of January. The ice edge is expected to reach Ninilchik by the end of January. The ice edge may reach Anchor Point by the end of January but more likely during the first half of February. $$ Schreck