ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 303 PM EDT SAT JUL 29 2017 VALID 12Z WED AUG 02 2017 - 12Z SUN AUG 06 2017 THE UPPER-LEVEL PATTERN STARTS OFF WITH A CLOSED LOW SOUTH OF THE STATE IN THE GULF OF AK/PACIFIC WITH A PROGRESSIVE SHORT WAVE TROUGH OVER THE WESTERN PORTION OF THE STATE. BOTH OF THESE FEATURES LIFT NORTH AND EAST ON WED, WHILE DIGGING SPLIT FLOW UPPER TROUGH APPROACHES THE BERING SEA. THIS HELPS SET UP THE NEXT CLOSED MID TO UPPER LOW FEATURE SSW OF THE STATE BY NEXT WEEKEND, WHILE AN EXTREMELY DEEP SYSTEM ALONG THE ARCTIC STREAM DIGS INTO RUSSIA AND POSSIBLY ALLOWS A LOWERING OF UPPER HEIGHTS TO REACH NORTHERN AK. OVERALL WPC FEELS THE 00Z/29 GFS IS A MUCH SOLID SOLUTION THAN THE 06Z AND 12Z GFS. THIS OPERATIONAL SOLUTION MIRRORS A BIT CLOSER TO THE 00Z/29 ECMWF AND IS MORE ALIGNED WITH THE STABLE MEANS, GEFS, ECMWF AND NAEFS. THUS A LARGE PERCENTAGE ON WED/THURS WAS BASED ON A BLEND OF THE 00Z GFS/ECMWF, BUT AN INCREASE OF THE MEANS UP TO 60 PERCENT WAS INCORPORATED THROUGH NEXT SAT. MUSHER