Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 543 PM EST Mon Dec 07 2020 Valid 12Z Fri Dec 11 2020 - 12Z Tue Dec 15 2020 ...Guidance and Uncertainty Assessment... Aside from an agreeable start to the forecast period on Day 4, the rest of the forecast remains challenging and complicated with plenty of uncertainty. The basic synoptic pattern is expected to feature fast zonal flow over the Gulf of Alaska while blocky ridging over the Chukchi Sea should allow troughing to maintain itself over the Interior. General storm tracks will favor over the Aleutians toward Southeast Alaska. The WPC blend this cycle favored the 12Z ECMWF/CMC deterministic solutions which maintains a solution consistent with continuity. The 12Z GFS was less preferred, even excluded by later periods, as it was showing very fast bias with the storm tracks and synoptic pattern, becoming out of phase with the other guidance and ensemble means. By day 6-8, higher components of the ECENS was used. ...Weather/Hazards Highlights... During Thu-Fri ahead of the strong Aleutians storm and its leading occluded front, expect an area of strong winds along with focused precipitation over the eastern Aleutians and possibly southwestern Alaska Peninsula. The high winds threat will transition across portions of the central/northern Interior this weekend. Precipitation should be light and scattered for most of the Mainland, aside from the coastal areas closer to the storm tracks. Temperatures are expected to favor below normal to much below normal, particularly for the central to northern Interior. Taylor Hazards: - High winds across portions of mainland Alaska and the Aleutians, Thu, Dec 10. - High winds across portions of mainland Alaska, Sat-Sun, Dec 12-Dec 13. Additional 3-7 Day Hazard information can be found on the WPC medium range hazards 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