496  
FXHW01 KWNH 270748  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
348 AM EDT THU MAR 27 2025  
 
VALID 00Z FRI 28 MAR 2025 - 00Z FRI 04 APR 2025  
 
THE FORECAST FROM NOW INTO THE WEEKEND HAS CHANGED LITTLE IN THE  
GUIDANCE OVER THE PAST COUPLE DAYS. EXPECT EAST/SOUTHEASTERLY  
TRADES DURING THIS PART OF THE FORECAST PERIOD. BACKGROUND FLOW  
SHOULD BE SUFFICIENT TO SUPPORT SOME WINDWARD FOCUS FOR SHOWERS  
OVER SOME AREAS WHILE AT OTHER TIMES/LOCATIONS IT MAY BE WEAK  
ENOUGH TO ALLOW FOR SEA BREEZE INFLUENCE. RAINFALL SHOULD BE  
LIGHTEST LATE THIS WEEK INTO THE EARLY WEEKEND TIME FRAME AS AN  
UPPER RIDGE BUILDS INTO AND SETTLES OVER THE AREA BEFORE SHIFTING  
EASTWARD.  
 
FOR NEXT WEEK THE GUIDANCE HAS BEEN SHOWING DRAMATIC SPREAD FOR  
PATTERN SPECIFICS ALOFT OVER THE EASTERN HALF OF THE PACIFIC, WITH  
SOME INFLUENCE ON THE SURFACE PATTERN. WITH IMPROVED CLUSTERING  
AMONG THE 00Z MACHINE LEARNING (ML) MODELS AND SOME HINTS IN THE  
00Z GEFS MEAN TOWARD THE ECMWF/CMC AND THEIR MEANS, THE 18Z/00Z  
GFS RUNS ARE LOOKING INCREASINGLY SUSPECT WITH THEIR DEEP EASTERN  
PACIFIC UPPER TROUGH--AND FRONT DROPPING DOWN CLOSE TO THE MAIN  
ISLANDS--AROUND TUESDAY/WEDNESDAY. THE MAJORITY CLUSTER SUGGESTS  
LOW LEVEL WINDS WILL TURN SOMEWHAT MORE SOUTHERLY AHEAD OF THE  
SYSTEM EVOLVING WELL TO THE NORTHWEST OF THE STATE. THIS MAY  
INCREASE MOISTURE TO SOME DEGREE WHILE THE BAND OF HEAVIER FRONTAL  
RAINFALL STAYS WEST OF THE MAIN ISLANDS THROUGH THURSDAY. RECENT  
ML MODEL RUNS HAVE KEPT THE RAIN BAND FARTHER WEST THAN SOME ECMWF  
RUNS AND GEFS/ECENS MEAN WHILE THE 00Z ECMWF HAS SHIFTED WEST TO  
FIT CLOSER WITH THE ML MODELS. THE WESTERN ALIGNMENT OF HEAVY RAIN  
SEEMS REASONABLE GIVEN THE STRENGTH OF THE UPPER RIDGE TO THE  
EAST OF THE STATE IN THE MAJORITY CLUSTER.  
 
RAUSCH  
 
 
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