033  
FXHW01 KWNH 080750  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
349 AM EDT MON APR 08 2024  
 
VALID 00Z TUE APR 09 2024 - 00Z TUE APR 16 2024  
 
THE FORECAST CONTINUES TO SHOW LIGHT TO MODERATE WINDWARD-FOCUSED  
SHOWERS EARLY THIS WEEK AS TRADES TREND GRADUALLY WEAKER, WITH A  
WEAKNESS ALOFT OVER/NORTH OF THE ISLANDS INTO EARLY TUESDAY LIKELY  
OFFSETTING SLIGHTLY BELOW NORMAL VALUES OF PRECIPITABLE WATER.  
OVER THE PAST DAY THE GUIDANCE HAS MAINTAINED GOOD CONTINUITY WITH  
A DEEP UPPER LOW CLOSING OFF TO THE NORTHWEST OF THE STATE BY  
WEDNESDAY-THURSDAY. THE UPPER LOW SHOULD DRIFT NORTHWARD  
THEREAFTER WHILE ENERGY DROPPING INTO THE BASE OF THE OVERALL  
TROUGH SHOULD ULTIMATELY LEAD TO SOME EASTWARD PROGRESSION OF THIS  
TROUGH BY SUNDAY-MONDAY. A SURFACE LOW CORRESPONDING TO THE UPPER  
SYSTEM SHOULD EXTEND A FRONT/CONVERGENCE AXIS SOUTHWARD TO JUST  
WEST OF THE ISLANDS DURING THE LATTER HALF OF THE WEEK INTO THE  
WEEKEND, HELPING TO FOCUS BANDS OF HEAVY RAINFALL AS PRECIPITABLE  
WATER VALUES INCREASE TO 1.5 INCHES OR MORE ACROSS THE STATE FROM  
LATE WEEK ONWARD. MOST DYNAMICAL AND MACHINE LEARNING GUIDANCE  
CURRENTLY SUGGESTS THAT KAUAI AND NIIHAU WILL BE ON THE EASTERN  
SIDE OF THE ENHANCED RAINFALL, WITH SLIGHT CHANGES IN LONGITUDE  
PRODUCING SIGNIFICANTLY DRIER OR WETTER CONDITIONS. LOW  
PREDICTABILITY FOR SUCH MINOR DIFFERENCES A FEW DAYS OUT IN TIME  
KEEPS CONFIDENCE IN SPECIFICS LOW WITHIN THE AGREEABLE LARGER  
SCALE EVOLUTION. MEANWHILE EXPECT WINDS OVER THE STATE TO TURN  
SOUTHEASTERLY BY WEDNESDAY AND PERSIST INTO THE WEEKEND. THERE IS  
REASONABLE AGREEMENT THAT THE AXIS OF ENHANCED RAIN SHOULD START  
TO ADVANCE EASTWARD AHEAD OF THE LINGERING UPPER TROUGH BY  
SUNDAY-MONDAY. LATEST GFS RUNS BY MONDAY SHOW A LITTLE MORE  
SOUTHEASTWARD AMPLITUDE OF THE UPPER TROUGH VERSUS OTHER GUIDANCE,  
BUT FOR NOW THIS DOES NOT SEEM TO LEAD TO PRONOUNCED DIFFERENCES  
WITH THE EASTWARD PROGRESS OF THE SURFACE REFLECTION AND  
ASSOCIATED RAINFALL.  
 
RAUSCH  
 

 
 
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