414  
FXHW01 KWNH 220742  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
342 AM EDT SAT MAR 22 2025  
 
VALID 00Z SUN 23 MAR 2025 - 00Z SUN 30 MAR 2025  
 
EXPECT TRADES TO TREND LIGHTER DURING THE WEEKEND AS A FRONT  
APPROACHES FROM THE NORTHWEST. WINDWARD SHOWER FOCUS WILL LIKELY  
TRANSITION TO SOME SEA BREEZE INFLUENCE WHERE WINDS BECOME  
SUFFICIENTLY WEAK. LATEST GUIDANCE SUGGESTS THE FRONT AND ITS  
ASSOCIATED MOISTURE AXIS SHOULD STAY JUST NORTH OF THE MAIN  
ISLANDS EARLY NEXT WEEK BEFORE WAVINESS TO THE WEST/NORTH LIFTS  
THE FRONT NORTHWARD. RECENT GFS TRENDS HAVE YIELDED BETTER  
AGREEMENT FOR HOW FAR TO THE NORTH THE AXIS OF HEAVIER RAINFALL  
SHOULD BE. GUIDANCE STILL SHOWS THE TRADES RETURNING BY TUESDAY  
AND CONTINUING IN EASTERLY OR SOUTHEASTERLY FASHION FOR THE REST  
OF THE WEEK, FAVORING ANOTHER PERIOD OF WINDWARD SHOWERS. AN UPPER  
RIDGE THAT BUILDS IN FROM THE SOUTHEAST BY LATE WEEK SHOULD HELP  
TO KEEP RAINFALL TOTALS IN THE LIGHT TO MODERATE RANGE.  
 
BY NEXT SATURDAY THE GFS/GEFS DIVERGE FROM MOST OTHER GUIDANCE IN  
SHOWING A MORE AMPLIFIED EAST-CENTRAL PACIFIC UPPER TROUGH,  
DISPLACING THE UPPER RIDGE OVER THE STATE FARTHER SOUTHWESTWARD.  
THE GFS/GEFS UPPER PATTERN LEADS TO A GREATER SOUTHWARD PUSH OF  
HIGH PRESSURE FROM THE NORTH (WITH A LEADING FRONT) ALONG WITH  
NORTHEASTERLY WINDS. IN CONTRAST, MOST OF THE LATEST 00Z MACHINE  
LEARNING (ML) GUIDANCE HOLDS ONTO MORE UPPER RIDGING OVER AND  
NORTHEAST OF THE STATE LIKE THE ECMWF, WITH THE SURFACE PATTERN  
FAVORING CONTINUED EASTERLY/SOUTHEASTERLY WINDS. WILL FAVOR THE  
ECMWF PATTERN GIVEN SUPPORT FROM THE ML MAJORITY.  
 
RAUSCH  
 
 
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