Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 646 PM EDT Wed Apr 12 2023 Valid 12Z Sun Apr 16 2023 - 12Z Thu Apr 20 2023 ...Cold April pattern for much of Alaska may start to ease next week... ...Overview... Closed upper lows/upper troughing over the Arctic Ocean, through the mainland and additionally over the Gulf of Alaska are expected to remained roughly sandwiched between upper ridges centered both to the west and east of Alaska in a blocky pattern. The rather stable/stagnant pattern may be interrupted by weaker waves embedded with the flow, but overall this will promote a dry and cold period for most of the state, with most light to moderate precipitation set to linger from coastal South-central to Southeast Alaska. ...Guidance Evaluation/Predictability Assessment... The vast bulk of model and ensemble guidance maintains a quite similar mid-larger scale pattern Sunday-Tuesday. A 12 UTC ECMWF/UKMET/CMC blend seems to mitigate flow embedded feature differences consistent with a pattern with overall near average predictability. These models also dig energies more sharply southward than the GFS across the western Interior toward the northern Gulf of Alaska during this period. This seems to make more sense considering the amplitude and peristence of upper ridging to the west of the state. Replaced the CMC/UKMET with the GEFS/ECMWF ensemble means for Days 7/8 to better hold onto the current pattern/persistence (considering blocky flow) and to best maintain WPC product continuity. ...Weather/Hazard Highlights... Upper troughing will focus much below normal temperatures over the mainland for especially the West Coast and western Interior as high pressure over the Bering this weekend shifts northeastward to the Beaufort Sea next week. It may take until the middle of next week for any appreciable moderation in temperatures over the mainland to be realized, though this period will at least be milder than the deep cold in the near term. Initially strong pressure gradient between the Bering high and the Gulf low will favor NW gap winds from the eastern Aleutians to the AKPen which may exceed 40 kts this weekend into early next week. Moderate precipitation will be mostly confined to the Southeast as weakening occlusions and surface troughs rotate around the mean parent low position over the east-central Gulf of Alaska. The deepened main lows will present a protracted maritime threat. Schichtel Hazards: - High winds for the eastern Aleutians and Alaska Peninsula, Sat-Sun, Apr 15-Apr 16. - Much below normal temperatures for the West Coast and western Interior Alaska, Sat-Mon, Apr 15-Apr 17. 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