Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 659 PM EDT Fri Oct 07 2022 Valid 12Z Tue Oct 11 2022 - 12Z Sat Oct 15 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 solutions are well clustered Tuesday/Wednesday and a composite seems to offer a good basis for the main forecast components. The composite is well supported by ensembles and maintain good WPC product continuity. Increasingly transitioned to a more run to run consistent solution of the compatible 12 UTC GEFS/NAEFS/ECMWF ensemble means Thursday-next Saturday. A vigorous Bering Sea low slated to slam into western/southwestern Alaska Monday will lose organization but remain energetic/unsettled while working inland into Tuesday/Wednesday and spread a swath of lead precipitation and locally enhanced winds across the Brooks Range and Interior. Expect widespread post-frontal cooling in the wake of system passage across the region. While individual system timing and emphasis differences do grow into mid-late next week in amplifying/phasing flow, 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. There is a good signal for the tapping of additional mid-latitude Pacific system energy and long fetch moisture to fuel a renewed threat for multi-day heavy precipitation into south-central to southeastern Alaska given an emerging flow channel to the state in between the upper trough/ridge couplet. 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 early-mid next week to the Aleutians/southern Bering Sea then Southwest Alaska and the Alaska Peninsula 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 Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Wed-Thu, Oct 12-Oct 13. - Heavy precipitation across portions of the Alaska Panhandle, Thu-Fri, Oct 13-Oct 14. - High winds across portions of mainland Alaska, Mon, Oct 10. - High significant wave heights for coastal portions of mainland Alaska, Mon, Oct 10. 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