Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 700 PM EST Wed Dec 23 2020 Valid 12Z Mon Dec 28 2020 - 12Z Fri Jan 01 2021 ...Overview and Guidance/Uncertainty Assessment... Upper pattern will feature ridging from NW Canada atop troughing that will elongate across the North Pacific. A lead deep system (940s mb) will slowly dissipate in the Bering Sea early next week. The 12Z ECMWF/UKMET/Canadian have shifted southeastward with the parent low placement by 12Z Sun, though the 12Z GFS was a bit farther WNW closer to the ensemble means. Preferred the ECMWF-led consensus but with reservation as sometimes the deterministic models can lead the ensembles, but it's not a guarantee even at four days out. As the system unfolds to the east, blend of the guidance acted to tone down any one model solution which was the preference given the shorter-term uncertainty. This included the rather robust 12Z ECMWF. Phased out the Canadian as the GFS came back into better ECMWF/ensemble agreement by the end of the period across the North Pacific with another system, but trended nearly fully to the ensemble means by next Thu with low confidence in details and modest confidence at best in system placement. Upper low over the far western Pacific next Thu suggests low confidence in split flow to its east along the Dateline. ...Weather/Hazards Highlights... Deep system will bring windy conditions to the Aleutians/Bering and increased precipitation to the AKPen into southern coastal areas. Southeastern-facing areas of the Kenai peninsula may see several inches of precipitation in sustained onshore flow, perhaps aided by triple point or sfc wave development around next Mon. Less precipitation is forecast for the Panhandle as upper ridging maintains its presence. Temperatures will generally be near to above normal through the period. Fracasso 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 Hazards: No significant hazards are expected over Alaska during this forecast period. 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