Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 656 PM EDT Fri Apr 23 2021 Valid 12Z Tue Apr 27 2021 - 12Z Sat May 01 2021 ...Overview and Guidance/Uncertainty Assessment... The weather pattern is forecast to be relatively uneventful across most of Alaska during the medium range period. The upper level flow pattern is expected to feature a slow moving upper low over the Gulf of Alaska, while an upper ridge axis to the west helps to hold back any other significant energy from lifting north/east into the state. This is expected to keep the main storm tracks and significant sensible weather confined to the southern coastal areas. 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 for early to mid next week. The main difference was a faster and more amplified trough solution with the 12Z CMC across eastern Siberia. By Thursday, the GFS stands out with a strong upper low over the northern Bering compared to the other guidance, and this persists into the weekend. This was not supported much by the ensemble means, so it was weighted less in the forecast. The WPC blend leaned toward the 12Z ECMWF/CMC/EC mean along with some previous WPC continuity. ...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 and the Alaska Peninsula areas through the middle of next week. By late in the week, low pressure lifting northward across the Gulf of Alaska is expected to advect higher moisture into the area. With better forcing and dynamics, widespread precipitation is expected from Kodiak Island to the southeast Panhandle region. Some of this rainfall could be locally heavy. No significant temperature anomalies are forecast during this forecast period. Hamrick 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