ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 351 PM EDT FRI JUL 28 2017 VALID 12Z TUE AUG 01 2017 - 12Z SAT AUG 05 2017 THE PATTERN REPEATS ITSELF FOR AK OVER THE COMING WEEK, WITH AN ACTIVE ARCTIC JET TO THE NORTH, A WEAKNESS OVER THE BERING SEA/WESTERN AK AND THE PERSISTENT LOW AND TROUGH SOUTH OF THE STATE OVER THE GULF OF AK AND NERN PAC. IN FACT, IT IS BASICALLY SPLIT UPPER-LEVEL FLOW WITH PHASED FLOW PRIOR TO THE STATE AND UPPER DYNAMICS SLIDE SOUTH AND EAST THROUGH THE BERING SEA/WESTERN AK THROUGH THE ALEUTIANS. WPC FELT RATHER COMFORTABLE WITH THIS SCENARIO AND A START WITH A BLEND OF THE 06Z GFS AND 00Z ECMWF ON MOST FACETS INCLUDING THE SYNOPTIC SCALE REGIME AND MORE SMALL SCALE SHORT WAVE DETAILS. BY THURS/FRI, THE GLOBAL OPERATIONAL MODELS SHOW INCREASING SPREAD WITH THE DETAILS THAT BEGIN TO IMPACT THE LARGE SCALE. THUS WPC FOLLOWED A LARGE PERCENTAGE OF THE BLEND BASED ON THE MEANS, GEFS, ECMWF AND NAEFS. THIS LOCKS IN THE SYNOPTIC SCALE PATTERN BUT MUTES THE SHORT WAVE DIFFERENCES. SO BY NEXT FRI, THE SAME PATTERN REGIME APPEARS TO BE IN PLACES ACROSS AK AND SURROUNDING AREA. MUSHER