HAWAII EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 814 AM EDT MON APR 14 2014 VALID 00Z TUE APR 15 2014 - 00Z TUE APR 22 2014 SHORT-TERM SENSIBLE WEATHER APPEARS TO BE SOMEWHAT OF A PERSISTENCE FORECAST FOR THE NEXT 48 TO 72 HOURS...FOLLOWING THE EASTWARD MIGRATION OF A SURFACE HIGH/RIDGE ALONG 30N LATITUDE. THE STRONG SHORTWAVE INVOF 40N 172W WAS HANDLED REASONABLY WELL BY THE DETERMINISTIC 14/00Z ECMWF/GFS TO CONCLUDE THAT THE TRADES WILL RELAX ON THURSDAY AND FRIDAY. AT THE SURFACE AND ESPECIALLY ALOFT...AN EQUALLY-BLENDED SOLUTION INCLUDING THE 14/00Z GEFS/ECENS LOOKED REASONABLE THROUGH DAY 6 (SUNDAY) ACROSS THE NORTHERN PACIFIC. THIS ALLOWS A 500MB RIDGE TO BUILD INTO HAWAI'I FROM WEST-NORTHWEST TO EAST-SOUTHEAST...THEN SWEEP A LONGWAVE TROUGH INTO THE SUBTROPICS...IN RESPONSE TO A DEEP UPPER LOW SHIFTING INTO THE GULF OF ALASKA. THE DETERMINISTIC GFS COULD BE UTILIZED THROUGH DAY 4 WITHOUT REGRET AS A BASELINE FOR TRENDS IN THE TRADEWIND INTENSITY. THE 14/00Z ECENS WAS A TAD FASTER THAN THE GEFS MEANS WITH THE FLOW PATTERN ALOFT...BUT THE DIFFERENCES WERE TIED TO SURFACE PATTERN DEVELOPMENTS IN THE NORTHEAST GULF OF ALASKA AND DO NOT APPEAR TO IMPACT THE SUBTROPICS. THE 14/00Z DETERMINISTIC GFS WAS ACTUALLY A BETTER FIT TO THE ECENS MEANS THAN ITS OWN 14/00Z GEFS MEAN DURING THE DAY 3-5 PERIOD. AND THE DETERMINISTIC 14/00Z ECMWF WAS AN AGGRESSIVE...MORE AMPLIFIED SOLUTION IN THE CENTRAL PACIFIC AND GULF OF ALASKA. AT THIS POINT...IT (THE DETERMINISTIC ECMWF) IS A LOW-PROBABILITY OUTLIER (BEYOND DAY 6). VOJTESAK