Alaska Extended Forecast Discussion National Weather Service College Park MD 709 PM EDT Thu Oct 23 2025 Valid 12Z Mon 27 Oct 2025 - 12Z Fri 31 Oct 2025 ...Stormy pattern into the Gulf of Alaska and South/Southeast Alaska next week... ...Guidance Evaluation/Preferences... There is good guidance agreement with one major exception through medium-range time scales overall for the Alaskan domain in an increasingly stormy pattern. A composite blend of best clustered 12 UTC GFS/ECMWF/UKMET models seems reasonable into early next week for best details, especially important as ample upper trough energies translate robustly downstream from the Bering Sea to the Gulf of Alaska. This blend works well for most areas Tuesday into Wednesday except for the quite different handling of a lead deepening north Pacific storm system with an envelope of solutions ranging from lifting northward into the eastern Gulf of Alaska to a more eastward path with much less robust wind/wave and precipitation threats for Southeast Alaska. WPC progs show a reasonably deep storm near the centroid position between the farther north tracks of the 12 UTC GFS/Canadian and more southward solutions of the 12 UTC ECMWF/UKMET after collaboration with WFO Juneau. This scenraio will be re-evaluated as the variance signal improves with newer guidance. While upstream upper flow seems to favor northward lift of the storm, lower resolution ensemble and machine learning guidance has been more reluctant and mixed to embrace that path. Switched preference to a GFS/ECMWF/Canadian ensemble mean blend for mid-later next week in an emerging stormy pattern along/south of the state with overall above normal predictability. This blend was used to mitigate small-mid scale variances still present at these longer time frames, but less evident in the smoothed ensemble means. Expect deep and impactful system development within a renewed and impactful stormy pattern from roughly the Aleutians downstream to the Gulf of Alaska and southern/Southeast Alaska. ...Overview and Weather/Hazards Highlights... An amplified northern stream upper low/trough will shift robustly southeastward from the Bering Sea to the Gulf of Alaska early next week. Expect unsettled weather for coastal Southwest Alaska into the Aleutians and the Alaskan Peninsula/Southern Alaska. Inland impacts do not seem to reach normal hazards thresholds for most areas, but would include more susceptible Southeast Alaska recovery areas. However, downstream northern Gulf of Alaska system development with moderate precipitation along with wrapping and gap wind potential inpacts. In this pattern, a lead upper low/trough set to linger over the Gulf of Alaska into early next week will quickly lose influence. Meanwhile, an aforementioned storm in a renewed stormy pattern to the west is then expected to emerge/evolve to threaten the Aleutians before gaining strength and evolving steadly downstream mid-late next week across the Gulf of Alaska. This would set the stage for significant maritime hazards and lead into end of month heavy precipitation and high winds for South/Southeast Alaska including heavy mountain snows. 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