Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 533 PM EDT Tue Aug 23 2022 Valid 12Z Sat Aug 27 2022 - 12Z Wed Aug 31 2022 ...Stormy weather with heavy precipitation/strong winds to shift between the Bering Sea and southwest/western Alaska and the Gulf of Alaska and southern/southeast Alaska... ...Guidance/Predictability Assessment... There remains a strong guidance signal in support of the upcoming stormy and energetic pattern with overall good guidance agreement. However, the 12 UTC ECMWF/Canadian seem to cluster a bit better with GEFS/ECMWF ensembles through much of the medium range forecast period, especially at high latitudes. Accordingly, the WPC product suite was primarily derived from a composite blend of those with emphasis on the ECMWF days 4-6 (Saturday-Monday), then ECMWF ensemble mean amid slowly growing forecast spread for days 7/8 (next Tuesday/Wednesday) that have better defined embedded surface systems consistent with the favorable upper flow and WPC continuity. Forecaster manual adjustments were then applied to these blends to ensure deepened surface systems and enhanced winds/QPF considering dynamic upper support. The ECMWF also seems to have a deepened moisture signal (not the low) from the Aleutians Friday to the Southeast Panhandle Sunday associated with and in line with the extratropical track for current Typhoon Tokage. This would feed into the WPC Hazards Desk heavy rainfall threat depicted over Southeast Alaska that extends into next week. This overall plan maintains good WPC product continuity as collaborated with local Alaskan NWS forecast offices. ...Sensible Weather and Potential Hazards... An active weather pattern for Alaska and vicinity is on tap for this forecast period. There is strong guidance signal indicating that an amplified/energetic upper low/trough and regenerating surface lows/frontal systems will shift ample storm focus from the Bering Sea and southwest/western/Interior Alaska into Saturday to the Gulf of Alaska and southern/southeast Alaska this weekend through early-mid next week. This is expected to occur as additional storm energies consolidate well upstream early-mid next week from the Bering Sea toward western Alaska. These systems will all include threats for high winds/waves and heavy rainfall/mountain snows to spread across the broad region. Schichtel Hazards: - Heavy rain across portions of mainland Alaska, Fri, Aug 26. - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Sat-Tue, Aug 27-Aug 30. 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