Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 420 PM EST Sun Feb 21 2021 Valid 12Z Thu Feb 25 2021 - 12Z Mon Mar 01 2021 ...Stormy Pattern from the Bering Sea to the Mainland/Gulf of Alaska... ...Overview and Guidance/Uncertainty Assessment... The 12 UTC GFS/GEFS mean and 12 UTC ECMWF/ECMWF ensemble mean mid-larger scale solution evolutions are reasonably well clustered through medium range time scales. A composite solution is preferred to highlight the most predictable weather features as numerous smaller scale system differences linger. The WPC medium range product suite was derived from this blend along with the National Blend of Models in a pattern with near average forecast predictability/uncertainty. This solution maintains good WPC product continuity in a pattern with overall above normal predictability. ...Weather/Hazards Highlights... A series of deepening lows in an energetic Pacific stream will work across the Bering Sea/Aleutians all week in an active pattern. This favors a downstream warming trend across southwest Alaska and much of the Interior this week, but lingering upper troughing and flow underneath may inhibit warming over the North Slope and possibly the eastern Interior. A main storm track will focus precipitation and wind/waves into the Aleutians, the AKpen and southwest 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 with lows Thursday and again over the weekend. Farther north, this pattern will also allow ejecting Bering Sea system energies to work inland across the Interior along with support for moderate swaths of snow to focus near a southern Interior wavy front with greatest potential by Thursday and over the weekend. There is also an emerging guidance signal that shows a threat of a deep low development and approach into the Aleutians in about a week to monitor. 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