380  
FXHW01 KWNH 110840  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
440 AM EDT SAT APR 11 2026  
 
VALID 00Z SUN 12 APR 2026 - 00Z SUN 19 APR 2026  
 
...PERIODS OF HEAVY RAINFALL EXPECTED ACROSS THE ISLANDS THIS  
WEEKEND INTO EARLY NEXT WEEK...  
 
THE CLOSED UPPER LOW CURRENTLY SITUATED APPROXIMATELY 1000 TO 1100  
MILES TO THE NORTHWEST OF THE ISLANDS NEAR 36N 167W, WILL REMAIN  
NEARLY STATIONARY THROUGH LATE MONDAY, AND THEN ONLY BEGIN TO PUSH  
SLOWLY EASTWARD TUESDAY AND WEDNESDAY. THERE IS NO CHANGE TO  
PRIOR MODEL CONSENSUS OF MID TO UPPER LEVEL SOUTHWESTERLY TO WEST  
SOUTHWESTERLY FLOW ALOFT REMAINING ESTABLISHED ACROSS THE  
ISLANDS, ON THE SOUTHEAST SIDE OF THIS NEARLY STATIONARY CLOSED  
LOW. THIS WILL ALLOW AND AXIS OF MUCH ABOVE AVERAGE PW VALUES, 2  
TO 4+ STANDARD DEVIATIONS ABOVE THE MEAN TO PERSIST ACROSS THE  
ISLAND CHAIN THROUGH THIS WEEKEND AND INTO MUCH OF NEXT WEEK.  
 
SHORTWAVES IN THIS PERSISTENT SOUTHWEST MID TO UPPER LEVEL FLOW  
WILL CONTINUE TO ENHANCE LARGE SCALE UVVS IN THE ANOMALOUS PW  
AXIS, SUPPORTING ROUNDS OF HEAVY RAINFALL AND AN ELEVATED RISK OF  
LIFE THREATENING FLASH FLOODING AND MUDSLIDES/DEBRIS FLOWS THIS  
WEEKEND AND POSSIBLY FOR PORTIONS OF THE UPCOMING WEEK. WHILE  
THE ANOMALOUS PW AXIS IS EXPECTED TO REMAIN ACROSS THE ISLANDS  
THROUGH MUCH OF THE UPCOMING WEEK, MODELS CONTINUE TO BE MORE  
EMPHATIC ABOUT HEAVY RAIN CHANCES THROUGH THE WEEKEND AND MONDAY  
FOR THE WESTERN TO CENTRAL PORTION OF THE STATE. AFTER THIS,  
MODEL QPF IS NOT AS FOCUSED, BUT LOCALLY HEAVY RAINS ARE STILL  
POSSIBLE GIVEN THE MUCH ABOVE AVERAGE PW VALUES REMAINING ACROSS  
THE STATE AND POTENTIAL FOR ADDITIONAL SHORTWAVES IN THE ABOVE  
MENTIONED WEST SOUTHWESTERLY TO SOUTHWESTERLY MID TO UPPER LEVEL  
FLOW.  
 
THROUGH THE FORECAST PERIOD, THE TYPICAL TRADE WIND PATTERN WILL  
REMAIN DISRUPTED. A RETURN TO A MORE NORMAL TRADE PATTERN MAY  
OCCUR LATE IN THE UPCOMING WEEK.  
 
ORAVEC  
 
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