Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 634 PM EDT Fri Jul 30 2021 Valid 12Z Tue Aug 3 2021 - 12Z Sat Aug 7 2021 ...Overview and Guidance/Predictability Evaluation... Model guidance is in good agreement overall, especially through Thursday, on the overall synoptic scale pattern across the Alaska domain. A rather amplified upper level pattern should be in place with a bit of an omega block setting up. A large upper low over the Bering Sea and another upper low over the eastern Gulf will be separated by a narrow upper ridge axis over the Alaska mainland. The ridge will tend to limit the overall eastward progression of the Bering Sea low, and this will likely force shortwave perturbations northward across the Aleutians and the west coast of mainland Alaska. There will also be a frontal boundary across the Interior for much of the forecast period with a weakening cold front along the southern coast. A blend of the 12Z GFS/ECMWF/CMC was used as a starting point in the forecast process for fronts/pressures through Thursday, and slightly more of the EC/GEFS means for Friday and Saturday. ...Weather/Threats Highlights... Moisture advection surging northward ahead of the Bering Sea trough/upper low is expected to result in rounds of showers and perhaps some thunderstorms across portions of western Alaska for the beginning to middle of next week. A cold front working its way across the western Mainland by Wednesday should help bring some moisture into southern Alaska as well. The central and eastern Aleutians should be the recipients of the heaviest QPF, with 1 to 2 inches of rainfall possible next week. Moderate to locally heavy rainfall is also possible across portions of the Panhandle region as a closed low lingers in the eastern Gulf. The upper ridge across the Interior should result in temperatures that are above seasonal averages across much of central and southern Alaska for the beginning of the forecast period. Considerably cooler readings are expected across the Brooks Range and the North Slope where an Arctic surface high will be governing the weather pattern north of a quasi-stationary front. Hamrick Hazards: - None posted Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook 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