Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 357 PM EDT Fri Sep 20 2019 Valid 12Z Tue Sep 24 2019 - 12Z Sat Sep 28 2019 The mean pattern for the extended periods has a low/trough over the Bering Sea and ridging over western Canada/eastern Gulf of Alaska. Guidance shows that multiple low pressure systems will track from the Bering Sea across the Aleutians into the central Gulf and portions of the Mainland. However, model spread/phasing begins by the 24th and increases through the end of the forecast period. The models seem to be struggling with the evolution of Typhoon Ta pah, which is contributing to the strength of pressures, timing and track. This forecast package primarily used nearly 50% weighting of the ECENS/GEFS/NAEFS means and about 50% ECWMF and GFS. In general, this will be favorable for wet conditions for southern portions of the Mainland and the panhandle. The ridging will help the northern part of the state transition from a cool and wet pattern to a drier and near normal air mass. Campbell 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: - Heavy rain across portions of the Alaska Panhandle, Mon-Tue, Sep 23-Sep 24. 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