Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 500 PM EST Thu Feb 18 2021 Valid 12Z Mon Feb 22 2021 - 12Z Fri Feb 26 2021 ...Overview and Guidance/Uncertainty Assessment... The 12 UTC GFS/ECMWF/Canadian models and GEFS/ECMWF ensemble means solutions offer reasonable continuity and are overall better clustered today Monday into Wednesday, bolstering forecast confidence. The GFS seems more of an outlier aloft over the Gulf of Alaska next midweek and the ensemble means show better consistency than all models by days 7/8 as predictability decreases toward average levels. The WPC medium range product suite was primarily derived from these WPC blends along with the 19 UTC National Blend of Models. ...Weather/Hazards Highlights... Expect much below normal temperatures for much of the Interior into Southcentral Alaska to persist Monday into Tuesday in a pattern with lowered heights underneath an Arctic Ocean upper vortex. Heights rise and temperatures moderate some by midweek with Bering Sea system progression. In a storm track to the south, a lead system working across the Gulf of Alaska early next week may yield moderate to locally heavy rain/snow over the Southeast Panhandle as enhanced by favored terrain. Upstream, the flow may tend to amplify as a series of deepening lows work into the Bering Sea Mon/Tue then again around Thu. These will focus rain/snow into the Aleutians and southwestern Alaska as they progress eastward, with main energies tracking into the unsettled Gulf of Alaska next Wednesday and Thursday that may support renewed heavier precipitation into the Southeast Panhandle. Schichtel Hazards: - Heavy precipitation across portions of the Alaska Panhandle, Sun-Mon, Feb 21-Feb 22. - Heavy precipitation across portions of the Alaska Panhandle, Wed, Feb 24. - Much below normal temperatures for parts of mainland Alaska, Sun-Tue, Feb 21-Feb 23. 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