Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 644 PM EDT Tue Apr 12 2022 Valid 12Z Sat Apr 16 2022 - 12Z Wed Apr 20 2022 ...Deep Extratropical Low associated with current west Pacific Typhoon Malakas to affect the Aleutians Sunday-Tuesday... ...Pattern and Weather/Hazard Highlights... A deep extratropical low associated with current west Pacific Typhoon Malakas is forecast to approach the Aleutians for the beginning of next week. Wrapping rains driven by high winds with the significant storm will also offer a widespread maritime threat. Otherwise, an upper level ridge axis should remain in place across much of mainland Alaska, with a surface high settling north of the Arctic Coast. However, a weak undercutting upper low will likely track westward across the Interior this weekend and then meander over the Bering. Meanwhile, a strong low pressure system over the Bering through the end of the week should weaken by the weekend. In this pattern, much of the state should begin the period with temperatures generally near to above average, and then colder weather arrives in time for the weekend for eastern areas of the state as cold air moves in from western Canada. Milder conditions should continue into early next week for northern Alaska near a closed upper high and over the southwestern mainland with deep Aleutian system affect. In terms of precipitation, most of the Interior region should remain dry and any periods of rain and mountain snow will likely be modest for southern and southeast Alaska as storm systems spin well offshore. ...Guidance/Predictability Assessment... Guidance signal has improved with respect to a track to affect the Aleutians Sunday-Tuesday of a deep extratropical low associated with current west Pacific Typhoon Malakas and the WPC Hazards Outlook desk has introduced graphical threats for the system. A composite of best clustered guidance from the 12 UTC GFS/ECMWF/Canadian and GEFS mean through medium range time scales seems to reasonably fit the latest official system track and also for most other features evident over the rest of Alaska. This solution maintains good WPC product continuity and system detail consistent with a pattern with near average predictability. Schichtel Hazards: - Heavy precipitation across portions of the Aleutians, Sun-Mon, Apr 17-Apr 18. - High winds across portions of the Aleutians, Sun-Mon, Apr 17-Apr 18. - Heavy precipitation across portions of eastern Aleutians to the Alaska Peninsula, Tue, Apr 19. - High winds across portions of the eastern Aleutians to the Alaska Peninsula, Tue, Apr 19. 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