Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 644 PM EDT Thu Apr 22 2021 Valid 12Z Mon Apr 26 2021 - 12Z Fri Apr 30 2021 ...Overview and Guidance/Uncertainty Assessment... A fairly benign weather pattern is forecast across Alaska during the medium range day 4-8 period. The upper level flow pattern is expected to feature slowly filling closed low over the Aleutians while somewhat blockiness ridging to the west holds back any other significant energy from lifting north/east into the area. This is expected to keep the main storm tracks and significant sensible weather to the south with perhaps brushing the southern coast. By the end of the period, an increase in moisture could bring more unsettled weather to the southeastern areas as low pressure finally lifts northward in a bit more progressive upper level flow pattern. The latest model guidance showed fairly good agreement and predictability early on. The main issues noted were the faster GFS bias with the progression/evolution of the upper level shortwaves. By day 6, the differences between the faster GFS and somewhat slower than consensus ECMWF were notable. The CMC offered a reasonable consensus solution. Even the ECENS/GEFS means were fairly separated by day 7/8, lowering confidence during that period. The WPC blend leaned toward a slower solution with more inclusion of the ECMWF/CMC and ECENS for the later periods. This blended fairly well with continuity forecast. ...Weather/Hazards Highlights... The majority of the state should remain dry through the first half of the period with any precipitation chances confined to the Aleutians/Alaska Peninsula areas early next week. By the middle to latter portions of the period, low pressure lifting northward into the Gulf of Alaska is expected to push higher moisture into the area. With better forcing/dynamics, widespread precipitation is expected for the southeastern areas. Some of this could be locally heavy. No significant temperature anomalies are forecast during the period. Taylor Hazards: -Heavy precipitation across portions of the Alaska Panhandle, Wed-Thu, Apr 28-Apr 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