Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 610 PM EDT Mon Nov 01 2021 Valid 12Z Fri Nov 05 2021 - 12Z Tue Nov 09 2021 ...Overview and Model Guidance... Offshore storms will mainly affect coastal Alaska for the next week. The flow will feature several potent Gulf of Alaska lows rotating around a closed upper trough and as escaping Bering Sea and Gulf of Alaskan impulses lift around the western periphery of an amplified but slowly weakening western Canada to Alaskan Interior upper ridge. Forecast spread has improved slightly over medium range time scales and a blend of best clustered guidance from the 12 UTC GFS/ECMWF (along with small smoothing inputs from the GEFS/ECMWF ensemble means consistent with a pattern with near normal predictability) seems to offer a reasonable solution for days 4/5 (Friday-Saturday). Forecast spread increases more rapidly after that and WPC blend weighting switches focus from the GFS/ECMWF (for some detail consistent with below normal predictability) to mainly the still compatible GEFS/ECMWF ensemble means for days 6-8 (Sunday-next Tuesday). This forecast strategy maintains decent WPC product continuity. ...Weather/Hazard Highlights... A compact and moist extratropical low associated with former Typhoon Malou is expected to lift from the eastern to northern Gulf of Alaska Friday/Saturday and offer some focus for enhanced precipitation into Southeast to south-central coastal Alaska. Meanwhile, Bering Sea systems will combine with energies lifting on the western periphery of an amplified Interior upper ridge position to focus periods of enhanced precipitation into western Alaska. In this pattern, the central and eastern Interior through the North Slope should enjoy much above normal readings through the weekend with some readings more than 20 degrees above normal before moderating into next week. Meanwhile, deep energy digging underneath into the Gulf of Alaska late week into early next week will present a favorable environment for offshore storm genesis with amplified/closed upper trough development to present a periodic maritime and southern/southeastern coastal tier threat. However, particular deep storm depiction at these longer time frames remains uncertain given run to run guidance variance and limited ensemble clustering. Schichtel Hazards: - Heavy precipitation across the eastern portion of the Kenai Peninsula, Thu, Nov 4. 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