Alaska Extended Forecast Discussion National Weather Service College Park MD 610 PM EDT Tue Oct 21 2025 Valid 12Z Sat 25 Oct 2025 - 12Z Wed 29 Oct 2025 ...Guidance Evaluation/Preferences... Guidance continues to show relatively good agreement on the overall large scale pattern, albeit with expected uncertainty in the details. Best forecast clustering is evident this period over the weekend into Monday when a 12 UTC GFS/ECMWF/UKMET/Canadian model blend is favored to mitigate lingering smaller scale differences consistent with individual predictability. Opted to switch to preference of compatible 12 UTC ECMWF/NAEFS ensemble means at longer time frames amid quickly growing forecast spread and lowering predictability. This solution offers a moderate depiction of a possibly deeper low over the eastern Gulf of Alaska with a centroid position between deeper 12 UTC GFS/ECMWF explicit solutions in an uncertain but overall favorable pattern. ...Overview and Weather/Hazards Highlights... A main upper low will drift slowly southeastward over the Bering Sea while multiple waves rotate around it. The upper low/trough is forecast to elongate by early next week as energies shift from the Bering Sea into the Gulf of Alaska. This will act to kick a lead upper low/trough set to linger over the Gulf through the weekend. This upper level pattern will produce several surface low pressure systems that will track over the Bering Sea/Aleutians to the Gulf of Alaska. Expect generally unsettled weather for West/Southwest through the Aleutians to Southern/Southeast Alaska in this pattern. There is also some signal to monitor for an aforementioned deep low to lift from the north Pacific to the eastern Gulf in a week. Mainly benign weather is expected for much of northern and interior Alaska with relatively higher pressure forecast to develop over these regions this weekend into next week. High pressure combined with generally southerly flow will result in above normal temperatures through the period. Schichtel 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