Alaska Extended Forecast Discussion National Weather Service College Park MD 628 PM EDT Sat Aug 16 2025 Valid 12Z Wed 20 Aug 2025 - 12Z Sun 24 Aug 2025 ...Guidance Evaluation/Preferences... The 12z guidance is in relatively good agreement on the overall synoptic pattern across the Alaska region during the medium range period. The Canadian deviates from the rest of the guidance by day 7 with a very deep arctic low pushing into northern Alaska and then another over-amplified Bering Sea low on day 8. The Canadian is a bit more progressive than the rest of the guidance over the Gulf of Alaska on days 5 and 6. A general model blend favoring the Euro is used on days 4 and 5. A more equitable blend consisting of deterministic and ensemble (GEFS/ECE) is deployed on day 6 followed by heavier weighting given to the ensembles on days 7 and 8. ...Weather/Hazards Highlights... The synoptic pattern across the Alaska region on Tuesday will feature ridging over the Bering Sea, a deep Arctic low that will likely persist through the rest of the week, and troughing in the Gulf. Shortwave energy is likely to rotate through the southern periphery of the Arctic low and kick-off an active period of precipitation across much of the mainland beginning Wednesday and continuing through the weekend. A deep surface low pressure system is expected to emerge over the Bering late next week and bring a substantial plume of moisture to the State. Heavy rain is possible across portions of the West Coast into interior areas next weekend. High temperatures will likely remain average across the mainland, while widespread cloud cover will probably keep overnight temps above average. Temperatures across the panhandle will be above average due to persistent troughing in the Gulf sending warm southerly air into the region. Kebede 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