Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 537 PM EDT Wed Mar 24 2021 Valid 12Z Sun Mar 28 2021 - 12Z Thu Apr 01 2021 ...Powerhouse weekend Bering Sea low to slam into the Alaskan mainland into early next week... ...Guidance/Uncertainty Assessment... The latest model and ensemble solutions are much better clustered than normal days 4-8, further bolstering forecast confidence in a stormy pattern. The 12 UTC GFS/ECMWF seem most reasonable (Sunday-Tuesday), while the 12 UTC GFS and the 12 UTC GEFS/ECMWF ensemble means seem best clustered days 7/8 (Wednesday-next Thursday). This methodology maintains excellent WPC continuity. Remaining guidance options are also well clustered at mid-larger scales. ...Weather/Hazards Highlights... A lead system with amplified upper trough support will work emerge over the eastern Gulf of Alaska this weekend. This will support a threat for terrain focusing heavy precipitation into the Alaskan Panhandle before exiting the region. Upstream, a powerhouse low with highly favorable upper support is meanwhile expected to emerge back into the Bering Sea this weekend and provide a significant maritime and Aleutians threat. The storm is expected to reach/spread highly unsettled conditions over the mainland then the Gulf of Alaska late weekend through next midweek. This will include a likely threat of enhanced wrapping snows/precipitation and high winds/waves. This continues to have a strong guidance signal to be a major and protracted storm. Schichtel Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat, Mar 27 and Tue-Wed, Mar 30-Mar 31. - Heavy snow across portions of mainland Alaska, Sun-Mon, Mar 28-Mar 29. - High winds across portions of mainland Alaska and the Aleutians, Sun-Mon, Mar 28-Mar 29. 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