141  
FXHW01 KWNH 250750  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
250 AM EST MON DEC 25 2023  
 
VALID 00Z TUE DEC 26 2023 - 00Z TUE JAN 02 2024  
 
THEMES PERSISTING FROM YESTERDAY INCLUDE SHOWERS STAYING ON THE  
LIGHT SIDE DUE TO PRECIPITABLE WATER VALUES STAYING BELOW  
CLIMATOLOGY, AND A PROGRESSION OF FRONTS THAT WILL LIKELY LEAD TO  
VARIABILITY IN WINDS AND SHOWER FOCUS. GUIDANCE HAS MAINTAINED  
REASONABLE AGREEMENT AND CONTINUITY WITH A LEADING FRONT SETTLING  
OVER THE STATE EARLY IN THE WEEK AND THEN DISSIPATING, WITH THE  
ASSOCIATED MODEST MOISTURE BAND LIKELY ENDING UP OVER THE CENTRAL  
ISLANDS AND/OR BIG ISLAND. HOWEVER MODELS/ENSEMBLE MEANS CONTINUE  
TO DIFFER FOR THE NEXT COUPLE FRONTS. FOR THE FRONT REACHING THE  
AREA BY FRIDAY, THE SPREAD RANGES FROM THE GFS ON THE SOUTH SIDE  
TO THE 00Z GEFS/12Z ECENS MEAN THAT ARE SOMEWHAT FARTHER NORTH AND  
00Z ECMWF NEAR THE MIDDLE. GUIDANCE VARIABILITY UP TO THIS POINT  
AND GFS INCONSISTENCY (SOME RUNS STRAYING TO THE SOUTH EXTREME OF  
THE ENVELOPE) SEEM TO FAVOR A MIDDLE GROUND CLOSEST TO THE ECMWF.  
THEN WITH THE NEXT FRONT AFFECTING THE AREA BY THE WEEKEND, THE  
GFS AND TO A LARGE DEGREE THE GEFS MEAN AS WELL ARE DEEPER THAN  
OTHER GUIDANCE WITH THE SUPPORTING UPPER TROUGH AND THUS PUSH THE  
FRONT FARTHEST SOUTH. THE 00Z ECMWF LOOKS MORE REASONABLE FOR  
THIS FRONT AS WELL, EVENTUALLY REACHING INTO THE MAIN ISLANDS BUT  
NOT PUSHING SOUTH LIKE THE GFS/GEFS. THE 12Z ECENS MEAN IS A TAD  
FARTHER NORTH AND THE 00Z CMC IS THE NORTHERN EXTREME.  
INTERESTINGLY, GUIDANCE ACTUALLY SHOWS LESS THAN THE EXPECTED  
SPREAD FOR THE NEXT FRONT APPROACHING FROM THE NORTHWEST LATE  
SUNDAY INTO MONDAY/NEW YEAR'S DAY AND A GENERAL COMPROMISE WOULD  
BE A GOOD STARTING POINT FOR THIS FRONT THAT MAY BRING A MODEST  
INCREASE OF MOISTURE INTO THE NORTHWESTERN ISLANDS.  
 
RAUSCH  
 

 
 
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