572  
FXHW01 KWNH 260756  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
255 AM EST SUN NOV 26 2023  
 
VALID 00Z MON NOV 27 2023 - 00Z MON DEC 04 2023  
 
HIGH PRESSURE MOVING EASTWARD TO THE NORTH OF HAWAII SHOULD BRING  
A BRIEF RETURN TO MODERATE TRADE WIND ACTIVITY SUNDAY INTO MONDAY  
WITH ADDITIONAL MOISTURE BEGINNING TO BE DRAWN NORTHWARD AROUND  
THE SAME TIME AS WELL AS SOUTHERN STREAM ENERGY BREAKS OFF, CLOSES  
OFF A LOW WEST OF THE STATE, AND THEN OPENS UP AGAIN AND ADVANCES  
EASTWARD AROUND MONDAY. AFTER THIS THOUGH, MODELS CONTINUE TO SHOW  
EXCELLENT AGREEMENT ON A KONA LOW SETTING UP WEST OF THE STATE  
AROUND MID WEEK WITH PRECIPITABLE WATER VALUES INCREASING UP TO  
TWO OR MORE STANDARD DEVIATIONS ABOVE NORMAL BY THURSDAY. THIS  
BRINGS AN INCREASED POTENTIAL FOR WIDESPREAD HEAVY RAINFALL AND  
THUNDERSTORMS TO SOME OR ALL OF THE HAWAIIAN ISLANDS  
THURSDAY-SATURDAY, WITH POTENTIAL ALSO FOR HEAVY SNOW IN THE  
HIGHEST TERRAIN OF THE BIG ISLAND. HOWEVER, THERE REMAINS A LOT OF  
UNCERTAINTY IN THE EXACT PLACEMENT OF THE LOW, WHICH HAS  
IMPLICATIONS FOR WHERE THE HEAVIEST RAINFALL SETS UP. THE 00Z GFS  
SUGGESTS THE HEAVIEST RAINS MAY REMAIN NORTHEAST OF THE ISLANDS,  
WHILE THE CMC AND ECMWF DO SUGGEST SOME RELATIVELY SIGNIFICANT  
RAINFALL TOTALS ACROSS ALL/PARTS OF THE HAWAIIAN ISLANDS. A  
GENERAL MODEL BLEND WITH THE ENSEMBLE MEANS SHOULD PROVIDE A  
RELATIVELY GOOD STARTING POINT AS THERE IS GOOD AGREEMENT ON THE  
LARGE SCALE. BY NEXT WEEKEND, THE GUIDANCE SHOWS THIS LOW  
WEAKENING AND SLOWLY BEGINNING TO DRIFT EASTWARD OVER THE ISLANDS  
WITH RAINFALL TRENDING LIGHTER WITH TIME.  
 
SANTORELLI  
 

 
 
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