Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 505 PM EST Sun Nov 05 2023 Valid 12Z Thu Nov 09 2023 - 12Z Mon Nov 13 2023 ...Multi-day Heavy Precipitation Threat from Southern to Southeast Alaska... ...Guidance Evaluation and Preferences... Guidance solutions seem reasonably well clustered valid for the Thursday into Saturday forecast. A preferred composite of the 12 UTC GFS/ECMWF/UKMET/Canadian models for best detail should offer a good forecast basis in a pattern with the expectation of above normal predictability. Given the favorable upper support signal, WPC progs depict deeper main offshore storms than continuity in this timeframe. Onward into later next weekend and early next week, opted to switch to still compatible GEFS/NAEFS/ECMWF ensemble means amid growing forecast spread. WPC product continuity overall reasonably well maintained with this forecast plan. ...Overview and Weather/Hazards Highlights... A series of dynamic/amplified upper troughs and main deepened surface lows/frontal systems will work from the southern Bering Sea and northern Pacific into and across the Gulf of Alaska this week. A lead storm in this forecast period is expected to work inland from the eastern Gulf of Alaska Thursday with another hot on its heels on a track from the southern Bering Sea/Aleutians through the Gulf of Alaska Thursday into next weekend. Yet another storm may reach the Bering Sea later next weekend, with trends showing a more northward track than the current pattern that may lead toward some effect into western Alaska by early next week to monitor. All these systems offer protracted maritime wind/wave threats. High winds and a deepened lead/rotating moisture feed looks to increasingly fuel development of an emerging heavy precipitation pattern, especially from Southcentral to Southeast Alaska. This will include threats for heavy coastal rains and inland/mountain snow, with ample precipitation totals and impacts accumulating mid-later week through next weekend. Meanwhile, lingering lowered heights and periodic pockets of modest moisture rotating over an unsettled Interior and North Slope may support scattered light snows next week with protracted easterly fetch winds offering blowing snow situations to monitor locally. 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