FZAK30 PAFC 231459 ICOAFC Sea Ice Outlook for Western and Arctic Alaskan Coastal Waters National Weather Service Anchorage Alaska 659 AM AKDT Friday 23 July 2021 ...JULY 2021 MONTHLY SEA ICE OUTLOOK… Looking at the big picture, sea ice breakup in the Chukchi and Beaufort Seas has been slower than in recent years. The sea ice area has not decreased significantly in the past month, likely because the sea ice in this area is thicker, including multi-year ice, than the ice farther south and weather patterns across the area have kept periods of northerly winds and cooler air over the region. As we look forward through the remainder of break-up season and into the start of freeze-up season, the sea surface temperatures are cooler than recent years especially across the southern Chukchi Sea. So freeze-up may not be quite as delayed as in recent years. Beyond October, there is a possibility for La Nina conditions to develop again which could keep the general storm track across the southern Bering Sea or just south of the Aleutian Islands. More details on that timeframe will be coming in future sea ice outlooks. Detailed information can be found in each pertinent section below. ...BREAK-UP OUTLOOK FOR THE CHUKCHI SEA… For Wainwright to Utqiagvik to 20 nm offshore, sea ice concentration will likely fluctuate for awhile as storm tracks move ice away from land and back toward it several times before the area is sea ice free for the season. Sea ice concentration less than 3 tenths is likely to come and go until the first week of August. Open water is expected during the second week of August. From Point Hope to Icy Cape, to 170W, sea ice concentrations less than 3 tenths can be expected by the end of July. This area will likely be sea ice free for the season by the middle of August. From Icy Cape to Utqiagvik to 170W, the timing that sea ice concentrations reach less than 3 tenths for the season varies widely from early July to late September, even within the last 10 years. This year the multi-year ice in the area will likely mean a break-up on the later end in this area. Sea ice concentration can be expected to decrease to 3 tenths by the beginning of September and be sea ice free by the middle of September. For North and West of Point Barrow to 75N and 170W, less than 3 tenths coverage is expected in the second half of September. This area may not become sea ice free before freeze-up begins. If it does, it would most likely be during the first half of October. ...BREAK-UP OUTLOOK FOR THE BEAUFORT SEA… In general, a large amount of multi-year sea ice in the Alaska waters of the Beaufort Sea will mean a later break-up than last year. Sea ice has begun to melt out from the Alaska coastline in July as well as westward from the Mackenzie River Delta in Canada. A relatively slow break-up is expected for the remainder of the Alaska waters of the Beaufort Sea. For Point Barrow to Cape Halkett up to 20 nm offshore, less than 3 tenths sea ice coverage is expected by the 3rd week of August. Open water is expected by the 1st week of September. For Cape Halkett to Flaxman Island up to 20 nm offshore, less than 3 tenths coverage is expected during the third week of August. Open water is expected by the end of August. For Harrison Bay to Demarcation Point to 20 nm offshore, less than 3 tenths coverage is expected during the second week of August. Open water is expected during the end of August. For Pt. Barrow to Cape Halkett to 75N, sea ice concentration may reach 3 tenths during the second half of September. If this area becomes sea ice free, it would likely happen toward the end of September or beginning of October. For Harrison Bay to Flaxman Island to 75N, sea ice may reach 3 tenths concentration during the end of September or beginning of October. This area is not expected to become sea ice free before freeze-up begins again. Sea ice free conditions to 72N or 73N by the end of September is more likely to occur. For Flaxman Island to Demarcation Point to 75N, this area is not expected to reach 3 tenths concentration this season as far north as 75N. More likely is that it would reach 3 tenths concentration to 72N during the second half of September or first half of October. ...FREEZE-UP OUTLOOK FOR THE BEAUFORT SEA… Freeze-up in the Beaufort Sea generally begins sometime between mid- September and mid-October depending on the weather patterns at the time and when colder air moves into the region. The dates in the following paragraphs may fluctuate by a week or two in either direction. Sea ice is expected to begin growing within the ice pack the last week of September or first week of October. Sea ice is expected to begin forming near freshwater river deltas and behind barrier islands of the north slope coast of Alaska during the first half of October. The first new ice beyond barrier islands out to 20nm offshore is expected around the middle of October. Sea ice concentration may reach 7 tenths out to 20nm offshore by the end of October. From Demarcation Point to Pt. Barrow offshore to 75N, sea ice growth is expected to expand south of the ice pack by the middle of October. Sea ice offshore within the Beaufort Sea is expected to merge with the new coastal sea ice by the end of October. ...FREEZE-UP OUTLOOK FOR THE CHUKCHI SEA… From Icy Cape to Utqiagvik, the first new sea ice formation is expected around the middle of October. This area may reach 7 tenths concentration by the end of October. Navigational waters around Point Barrow may reach 7 tenths concentration by the end of October, however it may not occur until the first half of November. For the area from Icy Cape to Utqiagvik offshore west to 170W, the first new sea ice is expected during the last week of October. For Point Hope to Icy Cape to 20nm offshore, the first new sea ice is expected during the first half of October. Sea ice may reach 3 tenths concentration by the end of October. For the Chukchi Sea from Pt. Barrow north to 75N and west to 170W, the first new sea ice is expected during the first half of October, and it may reach 7 tenths concentration by the end of October. For Kotzebue Sound, the first new sea ice is expected during the first half of October. Three tenths concentration may be reached by the end of October. For Cape Krusenstern to Point Hope to 20nm offshore, the first sea ice is expected to form during the second half of October. For Wales to Espenberg to 20nm offshore, the first new sea ice behind barrier islands is expected during the second half of October. ...FREEZE-UP OUTLOOK FOR THE BERING SEA… The first sea ice in the Bering Sea will most likely be in Norton Bay within Norton Sound. The first sea ice in this area is expected to form around the middle of October. The first sea ice along the Yukon Delta may form by the end of October. $$ Schreck