ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 143 PM EDT WED APR 27 2016 VALID 12Z SUN MAY 01 2016 - 12Z THU MAY 05 2016 LONGWAVE PATTERN REMAINS IN GOOD/GREAT AGREEMENT OVER ALASKA INTO NEXT WEEK. TROUGH/UPPER LOW IN THE GULF SUN/MON WILL LIFT NORTH AND WEAKEN AS INCOMING SYSTEM MOVES THROUGH THE ALEUTIANS MON-THU. BOTH THE 06Z GEFS AND 00Z ECENS MEANS ARE NEARLY ON TOP OF EACH OTHER THROUGHOUT THE PERIOD. RECENT DETERMINISTIC COUNTERPARTS -- GFS AND ECMWF -- HAVE WOBBLED ON EITHER SIDE OF THE ENSEMBLE MEANS SO A GENERAL COMPROMISE/BLEND WILL SUFFICE FOR MUCH OF THE FORECAST. THE ONE EXCEPTION IS IN THE GULF AND OVER THE PANHANDLE LATE SUN INTO MON WHERE A SFC WAVE WILL RIDE ALONG THE FRONT INTO SE ALASKA. THE ECMWF HAS SWING FROM EAST TO WEST OVER THE LAST DAY AND NOW TAKES THE LOW NORTHWARD THEN NORTHWESTWARD INTO THE CENTRAL NORTH GULF WHILE THE 00Z CANADIAN WAS FARTHER EAST. 12Z GFS AND 00Z UKMET OFFER A REASONABLE COMPROMISE POSITION IN LIGHT OF THE LARGE ECMWF SWING -- AND ALSO NOTED SHIFTS IN THE PAST FEW GFS RUNS. EITHER WAY, THIS WILL BRING A FAIR AMOUNT OF PRECIPITATION TO SE ALASKA. THE NEXT SYSTEM IN THE ALEUTIANS REMAINS RATHER WELL-FORECAST PER THE ENSEMBLES. 00Z GFS/ECMWF TAKE THE MAIN SFC LOW JUST NORTH OF THE ALEUTIANS BEFORE A WAVE ALONG THE FRONT MOVES NORTHEASTWARD TOWARD THE AKPEN. 12Z GFS WAS SOUTH OF THE ALEUTIANS WHICH IS STILL A POSSIBLE SCENARIO. ENSEMBLE MEANS LIE RIGHT ALONG THE ISLAND CHAIN BUT MAY BE TUGGED SOUTH BY THE SUBSEQUENT SFC WAVE DEVELOPMENT. KEPT CLOSE TO THE ENSEMBLE MEANS FOR NOW UNTIL A BETTER SIGNAL EMERGES. FRACASSO