Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 538 PM EST Wed Nov 11 2020 Valid 12Z Sun Nov 15 2020 - 12Z Thu Nov 19 2020 ...Guidance/Predictability Assessment... The WPC Alaskan medium range product suite was primarily derived from a composite blend of best clustered guidance from the 12 UTC GFS/ECMWF, 12 UTC GEFS/ECMWF ensemble means and the 19 UTC National Blend of Models day4/Sunday. Opted to quickly transition away from the GFS/ECMWF and toward the still compatible GEFS/ECMWF ensemble means and the National Blend of Models days 5-8 (Monday-next Thursday) in a period of increasing forecast spread and embedded system uncertainty, especially with offshore low developments. WPC continuity was reasonably maintained overall with this forecast strategy. ...Weather/Threats Highlights... Above normal temperature should persist over the North Slope for the next week and coastal western Alaska under upper ridging, but meanwhile expect quite a cooling trend that will lead to below to much below normal temperatures for much of the rest of the state as an amplified upper trough settles from the Interior down over the Gulf of Alaska. The upper trough favors unsettled conditions including some enhanced precipitation, especially for the Southeast Panhandle. Upstream, systems traversing the Bering Sea/Aleutians early next week will gradually weaken into the lead/amplified upper ridge, but still present unsettled maritime conditions and some onshore precipitation into western/northwestern Alaska. There is then also an increasing guidance signal supporting new upper trough/closed low development and approach into the Bering Sea and Aleutians next Wednesday/Thursday that would bring a threat of periods of enhanced winds/waves and precipitation across the region then into western and southwestern/southern Alaska. Schichtel 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 Hazards: - Much below normal temperatures across portions of mainland Alaska, Sun-Tue, Nov 15-Nov 17. 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