Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 453 PM EST Fri Feb 19 2021 Valid 12Z Tue Feb 23 2021 - 12Z Sat Feb 27 2021 ...Overview and Guidance/Uncertainty Assessment... The 12 UTC ECMWF/UKMET/Canadian models and GEFS/ECMWF ensemble means solutions offer reasonable continuity and are generally well clustered Tuesday-Thursday. A composite solution is preferred to highlight the most predictable weather features. The 12 UTC GFS seems more of an outlier. Leaned blend emphasis in favor of the ensemble means days 7/8 consistent with growing model forecast spread. The WPC medium range product suite was primarily derived from these WPC blends along with the 19 UTC National Blend of Models in a pattern with near average forecast predictability/uncertainty. ...Weather/Hazards Highlights... Expect much below normal temperatures for much of the Interior into Southcentral Alaska to persist Monday in a pattern with lowered heights underneath an Arctic Ocean upper vortex. Heights rise and temperatures moderate some by midweek with Bering Sea system approach, but may cool again later week as per a southward Arctic frontal sag. Meanwhile, a series of deepening lows in an energetic Pacific stream will work over the Bering Sea/Aleutians all next week in an active pattern. The storm track will focus precipitation and wind/waves to the Aleutians, the AKpen and southwest/western Alaska as they progress eastward, with energies to track into an unsettled Gulf of Alaska to support periodic heavier precipitation into southern and southeast Alaska. Schichtel Hazards: - Much below normal temperatures across portions of mainland Alaska, Mon, Feb 22. - Heavy precipitation for parts of the Alaska Panhandle, Mon, Feb 22 and Wed, Feb 24. - High winds across portions of the Aleutians, Fri, Feb 26. 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