Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 329 PM EST Sun Jan 24 2021 Valid 12Z Thu Jan 28 2021 - 12Z Mon Feb 01 2021 ...Bering Sea Storm to Threaten Alaska and the Gulf of Alaska into mid-late week... ...Overview and Guidance/Uncertainty Assessment... A powerful Bering Sea storm will slowly fill while spinning toward West/Southwest Alaska into Thursday-Friday, maintaining a maritime threat. Ample downstream energy transfers over the AKPen/Kodiak Island and the Gulf of Alaska meanwhile favor subsequent well organized maritime low redevelopment into late week. Guidance forecast clustering remains better than normal, bolstering forecast confidence. The WPC Alaskan medium range product suite was derived from reasonably well clustered guidance from the 12 UTC GFS/ECMWF/UKMET/Canadian models Thursday into Saturday along with the 19 UTC National Blend of Models. Increasingly adjusted blend focus from the models to the compatible GEFS/ECMWF ensemble means onward into early next week amid growing forecast spread. This maintains good WPC product continuity. ...Weather/Hazards Highlights... The deep Bering Sea low will spread heavy wrapping precipitation and a threat of high winds/waves across the Bering Sea and gradually fill Thursday-Friday while bringing an enhanced snow risk into West/Southwest Alaska with approach. Amplified upper ridging building over the Interior/North Slope in advance of the deep low will diminish, slated to reform back over the Bering Sea by next weekend. Forecast spread increases in Arctic stream flow rounding that retrograded ridge, but WPC guidance again allows a good venue for trough energies/height falls to dig/spread southward over a cooling/unsettling and locally snowy North Slope/Interior in a pattern favoring amplifying flow but limited moisture. Underneath, downstream transition across the AKPen/Kodiac Island will result in a pattern favorable for deepened Gulf of Alaska low development late week into next weekend. Guidance trends show a track offshore a cooled Southeast Panhandle and will present a maritime threat into next weekend. 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