Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 625 PM EST Tue Dec 10 2024 Valid 12Z Sat Dec 14 2024 - 12Z Wed Dec 18 2024 ...Storm-force winds near the northern Alaska coast, the Bering Sea, and the Aleutians at times; hurricane-force winds possible... ...Overview/Guidance Evaluation/Preferences... Guidance remains consistent and agreeable in showing that a mid-upper level ridge now across mainland Alaska will weaken over the weekend as a trough between the Sea of Okhotsk/Bering Sea and the Gulf of Alaska team up with a westward retrograding system from northwest Canada into the Alaskan Interior that tucks underneath a closed upper ridge/high over the Arctic Ocean. Within the west-to-east elongated upper trough, the main deep layered low is expected to be most persistent from the Bering Sea westward. It remains less certain on how much upper level troughing is expected across the Interior and whether or not a cyclone moves into the Alaska Peninsula/southeast Bering Sea this weekend. However, there does seem to be a growing guidance signal supporting deep closed upper low/surface storm development near the Aleutians late weekend into next week. For the WPC surface pressure progs, fronts, winds, and QPF/PoPs, used primarily a composite of the 12 UTC runs of the GFS/ECMWF and compatible GEFS/ECMWF ensemble means. The blending process tends to emphasize features consistent with individual predictability. The remainder of the grids were more 19 UTC NBM heavy, as usual, but were trended toward the latest 12 UTC ECMWF/ECMWF ensemble mean. Overall, WPC product continuity is reasonably maintained. ...Weather/Hazards Highlights... The interruption of the mid-upper level ridge over the Interior should allow an arctic drape/colder air to shift south into the far northern Gulf of AK, with outflow/gap winds expected through the usual spots of Southeast AK/the AK Panhandle. Temperatures across northeast AK, forecast to be the clearest portion of the state for the weekend into early next week, could fall as low as -30F, with wind chills down to -40F possible. With the arctic high over the Arctic Ocean, the threat of storm-force winds and possible blizzard conditions are also possible into later this week over far northern AK remains. An emerging deep cyclone position may meanwhile settle over the Aleutians/southern Bering Sea by the weekend to being storm-force to possibly even hurricane-force winds to monitor. Downstream system/energy translation should then boost precipitation intensity through early next week, especially from portions of the AK Peninsula and Kodiak Island eastward to the Kenai Peninsula, reaching Southeast Alaska by next midweek. Schichtel Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: The WPC Hazards Outline depicts thse threats. 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