Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EST Sat Nov 14 2020 Valid 12Z Wed Nov 18 2020 - 12Z Sun Nov 22 2020 ...Stormy Pattern next week for the Bering Sea and Gulf of Alaska... ...Guidance/Predictability Assessment... The WPC Alaskan medium range product suite was primarily derived from a composite blend of the compatible 12 UTC GFS/ECMWF, 12 UTC GEFS/ECMWF ensemble means and 19 UTC National Blend of Models days 4-8 in a pattern with average to above average system predictability. Inclusion in the composite of the ensemble means was intended to mitigate some model detail consistent with uncertainty, but then manually adjusted offshore lows deeper consistent with favorable upper support and model trends. ...Weather/Threats Highlights... Short range transition of an amplified upper ridge from the Bering Sea to over the Interior will moderate temperatures there significantly next midweek and foster a mainly benign pattern over the region as precipitation focusing upper trough energy lifts on the western periphery of this ridge over western/northwestern Alaska. Meanwhile, lead upper troughing held underneath over an unsettled eastern Gulf of Alaska and Southeast Panhandle will slowly weaken and lose influence over the area into Thursday. Upstream, there is now a strong guidance signal supporting amplified upper trough/closed low developments into the Bering Sea and Aleutians mid-later next week. These will offer several significant threats for deep offshore storms to focus enhanced winds/waves and precipitation across the region, then increasingly later next week/weekend into southwest Alaska, southern Alaska and then eventually southeast Alaska as ample upper trough/deepened storm energies work more in earnest into the Gulf of 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 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