ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 226 PM EDT WED JUN 21 2017 VALID 12Z SUN JUN 25 2017 - 12Z THU JUN 29 2017 ENSEMBLES SHOW DECENT AGREEMENT ON THE LONGWAVE PATTERN THAT FAVORS TROUGHING IN THE BERING SEA AND RIDGING OVER THE EASTERN HALF OF THE INTERIOR. AN UPPER LOW WELL NORTH OF THE NORTH SLOPE WILL MAINTAIN SW FLOW ALOFT FROM THE BERING STRAIT. IN THE GULF, A LEAD UPPER LOW WILL PUSH THROUGH THE PANHANDLE SUN/MON, THOUGH THE MODELS/ENSEMBLES SHOWED THE MOST RELATIVE SPREAD WITH THIS FEATURE. ANCHORED UPPER LOW IN THE BERING WOULD SUPPORT ANOTHER SYSTEM ROTATING AROUND FROM THE SOUTH AND TOWARD THE GULF LATER NEXT WEEK. RIGHT FROM 12Z/25, THE 06Z/12Z GFS RUNS WERE QUICKER THAN THE 00Z CLUSTER (00Z GFS SOMEWHAT IN BETWEEN) THAT INCLUDED THE ECMWF/CANADIAN/UKMET AS WELL AS CONTINUITY. OPTED TO STICK WITH THE GOING FORECAST VIA A BLEND OF THE 00Z GFS/GEFS AND MAJORITY WEIGHTING OF THE ECMWF/ECENS MEAN. FOR THE REMAINDER OF THE FORECAST, THE DETERMINISTIC MODELS SPLIT ON THE TIMING OF ANOTHER FEATURE OUT OF THE CENTRAL PACIFIC SO A TREND TOWARD THE ENSEMBLE MEANS (ECMWF A LITTLE MORE DEFINED) WORKED WELL TO START. NUDGED THE FONT MOVING THROUGH THE ALEUTIANS/BERING SUN-TUE A LITTLE QUICKER AS WELL AS THE TRAILING SYSTEM ON ITS HEELS. ENSEMBLE MEANS CENTERED NEAR THE AKPEN BY NEXT WED-THU BUT UPPER RIDGING BUILDING INTO THE INTERIOR WOULD LIKELY SUPPORT A FARTHER SOUTHEAST SFC LOW NEARING KODIAK PER THE ECMWF (OR EVEN THE CANADIAN). FRACASSO