ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 238 PM EDT SUN MAR 08 2015 VALID 12Z THU MAR 12 2015 - 12Z MON MAR 16 2015 THE MEDIUM RANGE FORECAST FOR ALASKA WILL EXHIBIT AN UPPER-LEVEL FLOW 'REVERSAL' OF SORTS---WITH THE FLOW ALOFT AMPLIFYING ACROSS THE EASTERN HALF OF THE GULF OF ALASKA AND PANHANDLE---AND UPPER-LEVEL RIDGING TO REPLACE A WESTERLY-ZONAL FLOW ACROSS THE INTERIOR. GIVEN THE COMPLEXITIES INVOLVED WITH A 'REVERSAL' OF THE FLOW PATTERN ACROSS THE STATE---THE 8/00Z ECENS/NAEFS AND THEIR DETERMINISTIC SOLUTIONS DID A REASONABLE JOB OF RESOLVING SOME OF THE KEY DETAILS HEADING INTO FRIDAY (13/12Z-14/00). HOWEVER...THERE REMAIN SOME LAT/LONG DIFFERENCES ON DAY 5-6 ACROSS THE ALEUTIANS AND SOUTHERN BERING SEA WITH A SURFACE CYCLONE TRACK MIGRATING EAST-SOUTHEASTWARD--- AS THE UPPER-LEVEL ZONAL FLOW AND ITS REMAINING COMPONENTS AT HIGH LATITUDE TRANSFER ENERGY DOWNSTREAM AND SOUTHEASTWARD INTO THE NORTH CENTRAL PACIFIC. ALONG THE WESTERN FLANKS OF THE BUILDING UPPER-LEVEL RIDGE ALONG THE WEST COAST OF CANADA...THE DIFFERENCES SURROUND THE OVERALL STRENGTH AND FORWARD SPEED OF A DAY 5-6 SHORTWAVE MIGRATING NORTHEASTWARD FROM THE SUBTROPICAL CENTRAL PACIFIC TO THE NORTHEAST GULF OF ALASKA/ALASKA PANHANDLE. WPC GRAPHICS UTILIZED A BLEND OF THE 8/00Z ECENS/NAEFS AND THE DETERMINISTIC ECMWF/CANADIAN TO 13/12Z---THEREAFTER BLENDING THE ECENS/NAEFS ENSEMBLE MEANS AT A 60/40 RATIO TO MITIGATE THE DIFFERENCES IN THE KEY FEATURES OF THIS EVOLVING PATTERN. VOJTESAK