Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EDT Fri Jun 21 2019 Valid 12Z Tue Jun 25 2019 - 12Z Sat Jun 29 2019 A relatively benign weather pattern will persist across Alaska during the medium range, with a persistent upper-level ridge axis extending from the North Pacific across western mainland Alaska north to the Arctic. Shortwave energy will traverse a mean upper trough centered across the western Bering Sea/western Aleutians, with a couple waves of low pressure traversing a weakening surface front across those areas. Meanwhile, on the eastern periphery of the upper ridge, weakening arctic cold fronts should move southward, bringing a return to near or slightly below average temperatures to the North Slope and eastern portions of the Interior, along with the potential for isolated to scattered showers. The WPC forecast was based heavily on the 12Z GFS and the GEFS ensemble mean, which resulted in a forecast relatively close to WPC continuity. The GFS has shown a much higher degree of run-to-run consistency across the past several runs relative to the ECMWF. The ECMWF has struggled with large changes as to whether the upper ridge breaks down and the resultant interactions of arctic and Pacific shortwave energy. Ryan Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php No significant hazards are expected over Alaska during this forecast period. 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