ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 229 PM EDT WED APR 29 2015 VALID 12Z SUN MAY 03 2015 - 12Z THU MAY 07 2015 OVER THE NORTH PACIFIC---A PERSISTENT WESTERLY FLOW ALOFT SHOULD MAINTAIN A FAIRLY PROGRESSIVE TREND TO THE PATTERN. THE SERIES OF SYSTEMS MIGRATING ALONG 50N LATITUDE AND INDIVIDUAL SHORTWAVE STORM TRACK DETAILS DO NOT APPEAR TO BE APPRECIABLY WET---FOR THE SOUTH COAST AND PANHANDLE. VERY LITTLE ADJUSTMENT WAS NEEDED TO THE DAY 4-6 WPC SURFACE AND 500MB FORECAST AND ONLY MINOR ADJUSTMENTS THEREAFTER TO ACCOUNT FOR AN INCREASING AMPLITUDE OF THE DOWNSTREAM UPPER-LEVEL RIDGE ALONG CANADA'S WEST COAST. THE ALASKA MEDIUM RANGE FORECAST PACKAGE CONTINUED TO FOLLOW A 70/30 BLEND OF THE 29/00Z ECENS AND NAEFS MEANS. COULD NOT FIND MUCH FAULT IN THE GEFS ENSEMBLE MEAN EITHER---AND A QUICK LOOK AT THE 29/12Z GFS FIT RATHER NICELY INTO THE CURRENT FORECAST PHILOSOPHY THROUGH DAY 7 (6/12Z). ITS OUTPUT COULD BE UTILIZED FOR A GUIDE FOR SOME OF THE SMALLER-SCALE DETAIL IN THE MEDIUM RANGE FORECAST---IF ONE CHOSE TO. VOJTESAK