Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 456 PM EST Mon Feb 22 2021 Valid 12Z Fri Feb 26 2021 - 12Z Tue Mar 02 2021 ...Quite a Stormy Pattern from the Bering Sea to the Mainland/Gulf of Alaska... ...Overview and Guidance/Uncertainty Assessment... Models and ensembles offer mid-larger scale solution evolutions that are reasonably well clustered through medium range time scales in an overall pattern with above average forecast predictability. A 12 UTC GFS/ECMWF/UKMET/Canadian model blend solution is quite representative day 4/Friday. However, prefer to focus increasingly upon a better clustered GEFS/ECMWF ensemble means composite days 5-8 to highlight the most predictable weather features as numerous smaller scale system differences linger. A smaller input of the still reasonably consistent deterministic models days 5-8 offers a bit more system detail consistent with uncertainty. The WPC medium range product suite was primarily derived from these blends along with the 19 UTC National Blend of Models. This forecast strategy maintains good WPC product continuity. ...Weather/Hazards Highlights... A deep lead low will work across the Bering Sea/Aleutians Friday. This favors a downstream warming trend across southwest Alaska and much of the Interior, but northern stream upper troughing may inhibit North Slope/northwest Alaskan warming. The storm will focus precipitation and wind/waves into the Aleutians, the AKpen and southwest Alaska, with weekend energies to work inland across the Interior to offer an enhanced snow threat. Deep low genesis this weekend over an unsettled northern Gulf of Alaska will support heavier precipitation into southern and southeast Alaska. Upstream, there is a growing guidance signal early next week for deep low development and track to the Aleutians/Bering Sea, southwest Alaska/AKPen/Kodiak Island and then the northern Gulf of Alaska. This offers maritime to onshore threats of heavy precipitation and winds/waves into these areas and then southern/southeast Alaska. Schichtel Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat-Sun, Feb 27-Feb 28. - High winds across portions of the Aleutians, Sun-Mon, Feb 28-Mar 1. - Much above normal temperatures for parts of mainland Alaska, Thu-Sat, Feb 25-Feb 27. 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