Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 634 PM EST Fri Dec 03 2021 Valid 12Z Tue Dec 07 2021 - 12Z Sat Dec 11 2021 ...Stormy pattern continues next week for Alaska... ...Overview and Guidance Evaluation/Preferences and Weather/Hazard Highlights... The Alaskan weather pattern will remain active into early next week as amplified upper troughing brings snowy storm energies into/across mainland Alaska. This system will weaken as it tracks through the Mainland, but enhanced winds and lingering snows may offer a significant local effect. Ample triple point development down along the southern Alaskan Gulf Coast by Tuesday should also send a lead front through the Panhandle region into midweek. Increasingly wet weather will work into parts of the Southern Coast and southeast Alaska into Tuesday and Wednesday with a threat for locally heavy snows with the low genesis, especially across favorable terrain. Upstream upper trough energies tracking to the Bering Sea by later next week now seem likely to support a deep low pressure system, albeit with continuing uncertainty on subsequent track into Alaska. This system has potential to be quite deep and presents a significant maritime and onshore threat. Guidance shows good agreement through Day 4/5 (Tuesday/Wednesday) and a composite of the well clustered 12 UTC GFS/ECMWF seems to offer a reasonable solution with above normal detail and predictability. Forecast spread and uncertainty increases quickly days 6-8 (Wednesday-next Friday), especially with model run to run continuity on the next main low towards the Bering Sea. Given trends and uncertainty, the WPC forecast progs used a blend of the now quite compatible 12 UTC GEFS/ECMWF ensemble means that offer a deep low on a middle of the road track between the more varied models across the Bering into Alaska. This approach also maintains better continuity with yesterday's WPC forecasts. Schichtel Hazards: - Heavy precipitation across portions of mainland Alaska, Mon, Dec 6. - Heavy precipitation across portions of the Alaska Panhandle, Tue, Dec 7. - High winds across portions of mainland Alaska, Mon, Dec 6. 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