Alaska Extended Forecast Discussion National Weather Service College Park MD 708 PM EDT Mon Sep 29 2025 Valid 12Z Fri 03 Oct 2025 - 12Z Tue 07 Oct 2025 ...Synoptic Overview... In the upper levels, an anchor low/trough will be in place generally across the Chukchi Sea throughout the period. A series of strong troughs will rotate eastward to the south of this anchor low, which will support the development of lows ahead of the trough that will keep the weather unsettled over the Bering and much of western Alaska. The biggest low will cross the Aleutians Friday, then move northeast over the middle of the Bering, where it will peak in intensity. The low will then weaken as it moves to the Bering Strait or far western Alaska Sunday and Monday. A new low races east across the Bering Monday into Tuesday, merging with the first low. A weak low over the Gulf Friday will quickly move inland Friday night into Saturday over the Panhandle, then ridging will make for more tranquil, if still cloudy weather to start the upcoming workweek. ...Guidance Evaluation and Preferences... While the track of the Bering low has stabilized from previous days, tracking from the western Bering to between St. Matthew & Nunivak Islands, then up western Alaska to the Chukchi Sea, the guidance is in less agreement on how fast it will move and how strong it will be. In keeping with continuity, the 00Z EC and 12Z CMC were used, which keep the low on that track while remaining at a good consensus of a peak intensity in the mid-970s followed by weakening and eventual merger with a secondary low by Monday and Tuesday near the Bering Strait. The other guidance was generally stronger, further west, and faster than this blend. Ensemble guidance in the form of increasing use of the ECENS was used for the D7/Monday and D8/Tuesday periods, as the guidance is in poor agreement on the incoming Kamchatka low that races east across the northern Bering. Thus, a 50-50 blend of the 00Z EC and 12Z CMC was used through D6, gradually blending in ECENS to a 60% ECENS and 20-20 split of the CMC/EC by D8. ...Weather/Hazards Highlights... There are no weather hazards to highlight for the period. There will be numerous areas to watch. As the big Bering low rapidly deepens Friday as it crosses the Aleutians, winds may gust at times to near the high wind criteria, especially on the east side of the low over the Central Aleutians. As the low approaches southwest Alaska, some amount of dynamic fetch may allow seas to grow to high surf levels in Bristol Bay, where it appears the greatest likelihood for prolonged onshore flow will be. Higher elevation snow will impact the Aleutian, Kenai, and eventually Chugach Ranges in southern Alaska, but freezing levels will remain high enough that the passes will not be affected. Heavy rain will be possible at times with the strongest upslope into those same coastal ranges at the lower elevations, but sustained/long- duration heavy rain is not expected. && Wegman Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html