FZAK30 PAFC 260041 ICOAFC Sea Ice Outlook for Western and Arctic Alaskan Coastal Waters National Weather Service Anchorage Alaska 340 PM AKST Wednesday 25 January 2023 ...JANUARY 2023 MONTHLY SEA ICE OUTLOOK… Looking at the big picture, the main ice pack in the Bering Sea has made significant progress southward since late December, with the ice edge now past Saint Matthew Island and continuing to progress toward Saint Paul Island. Sea ice has continued to struggle to establish in Bristol Bay though, as lows have continued to track across that area and sea surface temperatures have remained quite warm especially toward the outer part of the bay. As we look forward, La Nina conditions are expected to weaken and transition to ENSO-neutral through spring. A general storm track along and south of the Aleutian Islands will help sea ice advance more quickly than many recent years, though it is still not expected to be quite as early as last year. As La Nina begins to weaken over the next few months, the sea ice extent will likely not be quite as extensive as the 2021-2022 season though it is looking likely that it will reach St. Paul Island before retreating in earnest in the spring. Please note that while the general storm track is expected to remain across the southern Bering Sea and northern Pacific Ocean, some storms will likely track north into the Bering Sea and possibly the Chukchi Sea and this is taken into account in the following freeze-up and break-up dates. Detailed information can be found in each pertinent section below. …FREEZE-UP OUTLOOK FOR THE BERING SEA… The ice edge reaching Saint Paul Island happens about 50% of the years since 2000. Last year, in a similar La Nina climate regime the ice reached the area in the first half of February. Given the slow start to this season’s ice growth compared to last year, it is unlikely to happen as early unless a prolonged arctic outbreak becomes established. The most likely time frame for sea ice to reach Saint Paul Island is very late February or early March. Sea ice has reached Saint George Island about 45% of the years since 2000. During La Nina winters, when sea ice reached Saint Paul Island it also reached Saint George Island, though it is sometimes nearly a month after reaching Saint Paul Island. Therefore, if sea ice does reach Saint Paul Island this winter, it will likely also reach Saint George Island briefly before the ice pack retreats in spring. If it does, it would most likely happen in the second half of March. The coastal sea ice may reach Port Moller during the first half of February, though this extent along the Alaska Peninsula is looking unlikely this season. …BREAK-UP OUTLOOK FOR COOK INLET… South of Kalgin Island is expected to be sea ice free for the season during the second half of March. South of the Forelands is expected to be sea ice free for the season by the end of March. From the Forelands to Fire Island, sea ice concentration is expected to decrease to less than three tenths during the first half of April and be sea ice free for the season during the second half of April. Turnagain Arm is expected to be sea ice free for the season during the second half of April. Sea ice concentration within Knik Arm is expected to decrease to less than three tenths during the second half of April and be sea ice free for the season by the end of April. Cook Inlet is expected to be sea ice free for the season by the end of April. …BREAK-UP OUTLOOK FOR THE BERING SEA… If sea ice does reach Saint George Island, the last ice expected in that area will likely be in the last week of March or first week of April. If sea ice does reach Saint Paul Island, the last ice expected in that area will likely be during the second or third week of April. In Bristol Bay, sea ice concentration is expected to decrease to less than three tenths of the bay during the first half of April and be sea ice free for the season during the second half of April. Sea ice in Kuskokwim Bay may no longer be shorefast by the end of April, but more likely in the first half of May. $$ Schreck