Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 631 PM EDT Thu Apr 13 2023 Valid 12Z Mon Apr 17 2023 - 12Z Fri Apr 21 2023 ...Cold pattern for much of Alaska to ease next week... ...Overview... Upper lows/troughs over the Arctic Ocean, through the mainland and additionally over the Gulf of Alaska are expected to remaine roughly sandwiched between upper ridges centered both to the west and east of Alaska in a blocky pattern into next week. The recently 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 as lobes wrap around a mean upper trough position. ...Guidance Evaluation/Predictability Assessment... Models and ensembles show a reasonably similar larger scale pattern Monday-Tuesday. A 12 UTC GFS/ECMWF/UKMET/CMC blend seems to best mitigate flow embedded feature differences consistent with predictability. This solution is well supported by ensmebles. Opted to switch to just the 12 UTC GEFS/ECMWF ensemble means onward to better hold onto the current pattern 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 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 lows present a protracted maritime threat. Schichtel Hazards: - High winds for the eastern Aleutians and Alaska Peninsula, Sat-Sun, Apr 16-Apr 17. - Much below normal temperatures for the West Coast and western Interior Alaska, Sat-Mon, Apr 16-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