Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 629 PM EDT Sat Jun 18 2022 Valid 12Z Wed Jun 22 2022 - 12Z Sun Jun 26 2022 ...Overview... A ridgy pattern will stretch from the Alaska Peninsula into the northeastern mainland, separating a closed upper low moving from the Gulf of Alaska into the Alaska Panhandle/British Columbia and a deep layer cyclone across the Bering Sea/Aleutians. The upper high is forecast to be shunted southeastward into the southern mainland as the week progresses as longwave troughing becomes more established atop the Bering Sea/Aleutians. ...Guidance Evaluation/Predictability Assessment... The guidance shows reasonable agreement early; a compromise of the 12z GFS, 12z Canadian, 12z UKMET, and 12z ECMWF resolves any small issues. While the guidance shows some dispersion near the Aleutians late in the period at 500 hPa and the surface, the GFS, ECMWF, and Canadian show surprising agreement on the 5 day QPF covering day 4-8/Wednesday into next Saturday. To deal with the 500 hPa and surface pressure issues, used increasing amounts of the 00z ECMWF ensemble mean and 12z NAEFS mean with time, eventually becoming half of the overall blend. The remainder of the grids are based on a more even blend of deterministic and ensemble mean guidance, the National Blend of Models. ...Weather and Hazard Highlights... The Aleutians and western mainland Alaska should be the cloudiest and rainiest, with a couple inches of rain and gale force expected in the Aleutians, particularly Wednesday into Friday. Much of Mainland AK will be under the aegis of mid-level ridging and partly cloudy skies. Temperatures will become quite warm for interior southern and southeast AK, with 80s expected. Cooler conditions will be expected right along the coast, the Aleutians, and Brooks Range, but won't be particularly chilly when compared to June standards. Roth No significant hazards are expected over Alaska during this forecast period. 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