Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 309 PM EDT Mon Oct 14 2019 Valid 12Z Fri Oct 18 2019 - 12Z Tue Oct 22 2019 ...Guidance/Predictability Assessment... Guidance differences have increased some compared to the last few days with respect to small-mid scale weather focusing systems despite a still reasonably similar and energetic larger scale pattern evolution through medium range time scales. Prefer to still include some model with ensemble guidance for better detail and greater system strengths consistent with average predictability, but highly favorable upper trough/jet energy in an active/stormy pattern. The 12 UTC GFS/00 UTC ECMWF overall seem most compatable with GEFS/ECMWF ensembles. Accordingly, the WPC Alaskan medium range product suite was derived from a composite blend, weighing ensembles greater by day 7/8 amid growing system uncertainty. This solution maintains decent WPC continuity as collaborated with the Alaskan NWS forecast offices. ...Weather/Hazards Highlights... It remains the case that the infusion of the extratropical remains of former western Pacific super typhoon Hagibis into the Bering Sea well offshore Alaska will prolong unsettled weather as the system meanders under a closed upper trough. Unsettled conditions will persist from the Aleutians to southwest Alaska underneath in strong flow. Expect more modest conditions into western Alaska on the periphery of a lead and lingering low spinning over the eastern Bering Sea, with max supporting energies tranferring into the Gulf of Alaska. Meanwhile, these system energies will consolidate over the Gulf of Alaska into late week and support deepened low developments that will threaten maritime interests and bring enhanced precipitation into southern and southeast Alaska. There also remains a good guidance signal for two additional deepening low approaches from the south of the Aleutians northeast across the Gulf of Alaska next weekend into next week in a continuing stormy pattern. This again offers a threat of heavy precipitation for southern/southeastern Alaska into early next week. Schichtel 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 Alaska Hazards: - Heavy precipitation for the Alaska Panhandle and southern Alaska, Sun-Mon, Oct 20-Oct 21. 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