345  
FXHW01 KWNH 300755  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
354 AM EDT TUE MAY 30 2023  
 
VALID 00Z WED MAY 31 2023 - 00Z WED JUN 07 2023  
 
GUIDANCE CONTINUES TO SHOW A TRADE PATTERN THROUGH THE PERIOD,  
WITH WIND SPEEDS LIKELY TO PEAK IN THE MODERATE TO BRISK RANGE  
AROUND WEDNESDAY-THURSDAY, AND THEN FLUCTUATE THROUGH THE WEEKEND  
INTO NEXT WEEK. MODELS/MEANS HAVE TRENDED TOWARD A CENTRAL  
PACIFIC FRONT PUTTING MORE OF A DENT IN THE SUPPORTING SURFACE  
RIDGE DURING THE WEEKEND THAN FORECAST 24 HOURS AGO, THOUGH  
CONSENSUS SUGGESTS THAT THE 00Z GFS COULD BE OVERDONE WITH THE  
FRONT'S EFFECT. THUS TRADES MAY BE A LITTLE STRONGER THAN SEEN IN  
THE GFS DURING THAT TIME FRAME.  
 
PRECIPITABLE WATER VALUES SHOULD BE ABOVE CLIMATOLOGY AT LEAST  
THROUGH THURSDAY, IN ASSOCIATION WITH AN EAST-WEST WEAKNESS OVER  
OR JUST NORTH OF THE MAIN ISLANDS. WHILE SOME WEAK TROUGHING  
SHOULD PERSIST OVER AND WEST-SOUTHWEST OF THE STATE AFTER THE  
INITIAL WEAKNESS DISSIPATES, THERE IS NOW SOMEWHAT BETTER  
CLUSTERING TOWARD A DRIER TREND FROM FRIDAY ONWARD. THE ECMWF  
CONTINUES TO BE MOST AGGRESSIVE IN THAT REGARD, IN A COUPLE  
LOCALIZED CASES BRINGING PWATS NEAR OR SLIGHTLY BELOW AN INCH, AND  
THE 12Z ECMWF MEAN IS NEAR OR BELOW 1.25 INCHES. THE GEFS MEAN  
HAS MADE A NOTICEABLE DRIER TREND, NOW PROVIDING MORE SUPPORT FOR  
LEANING AWAY FROM THE 00Z GFS THAT KEEPS MORE MOISTURE NEAR THE  
BIG ISLAND FOR MOST OF THE PERIOD. GIVEN THE TRENDS IN MOISTURE  
OVER THE COURSE OF THE PERIOD, EXPECT SHOWERS TO PRODUCE THE MOST  
RAINFALL BETWEEN NOW AND THURSDAY WITH A GRADUAL LIGHTER TREND  
THEREAFTER. THE TRADES WILL SUPPORT PRIMARILY WINDWARD/MOUNTAIN  
FOCUS FOR SHOWERS THOUGH RAIN COULD OCCASIONALLY STRAY TO OTHER  
LOCALES.  
 
RAUSCH  
 

 
 
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