Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 624 PM EDT Sat Oct 08 2022 Valid 12Z Wed Oct 12 2022 - 12Z Sun Oct 16 2022 ...Heavy rainfall and elevation heavy snow threat for South-central to Southeastern Alaska mid-late next week to be rejuvenated into next weekend with approach of an Aleutians/Bering Sea storm... ...Guidance/Predictability Assessment and Weather/Hazards Highlights... The 12 UTC GFS/ECMWF/UKMET/Canadian models and GEFS/NAEFS/ECMWF ensemble mean solutions are well clustered Wednesday into next weekend and a composite blend seems to offer a good basis for the day 4-8 forecast and maintains good WPC product continuity. Yet another vigorous closed low settling over the high latitudes of the Arctic Ocean will favor the rotation of a series of progressive troughs underneath into the North Slope and Brooks Range in a periodically unsettled pattern that offers a threat for enhanced coastal surf and erosion. The pattern should also favor cooling down over the Interior, also in the wake of early week Bering Sea system passage across the region. Model and ensemble solutions still strongly favor a similar pattern evolution aloft and highlight development of an amplified upper trough from the Bering Sea through the Aleutians and amplified upper ridging building over the central to eastern Gulf of Alaska leading into mid-later next week. There is a good signal for the tapping of additional northern stream and mid-latitude Pacific system energy with long fetch moisture to fuel a renewed threat for multi-day heavy precipitation enhanced by topography into south-central to southeastern Alaska given an emerging flow channel to the state in between the upper trough/ridge couplet, albeit with slow pattern transition over time. Meanwhile, there remains an above normal ensemble guidance signal in support of yet another potent storm expected to track generally eastward from eastern Asia and the northwest Pacific into next midweek to the Aleutians/southern Bering Sea then Southwest Alaska and the Alaska Peninsula/Kodiak Island later next week. This storm is expected to then transition and increasingly reform later over the Gulf of Alaska in about a week along with mid-latitude influx to rejuvenate the wet pattern across south-central and southeast Alaska. This deep low also offers a wind/waves and wrapping enhanced rainfall threat broadly along the full path of the system. Schichtel 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