749  
FXHW01 KWNH 180810  
PMDHI  
 
HAWAII EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
410 AM EDT TUE AUG 18 2026  
 
VALID 00Z WED 19 AUG 2026 - 00Z WED 26 AUG 2026  
 
A TRADE WIND PATTERN IS GENERALLY EXPECTED OVER THE NEXT SEVERAL  
DAYS, WITH THE TYPICAL WINDWARD SHOWER ACTIVITY. A WEAK WAVE OF  
LOW PRESSURE MOVING NORTH OF THE ISLANDS BY THURSDAY INTO FRIDAY  
MAY DISRUPT THE TRADES AND SLIGHTLY INCREASE INSTABILITY OVER THE  
AREA. STILL LOOKING AT SCATTERED SHOWER ACTIVITY, BUT MAY BE MORE  
SEA BREEZE AND TERRAIN INDUCED COMPARED TO THE TYPICAL WINDWARD  
TRADE SHOWERS.  
 
NHC IS TRACKING ANOTHER TROPICAL WAVE WELL SOUTHEAST OF THE  
ISLANDS, WITH A 50% CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE  
AS OF EARLY TUESDAY. THIS WAVE WILL TRACK WESTWARD, WITH MOST  
MODEL AND ENSEMBLE SOLUTIONS CONTINUING TO KEEP IT SOUTH OF THE  
ISLANDS THIS WEEKEND INTO EARLY NEXT WEEK. TRENDS WILL CONTINUE TO  
BE MONITORED OVER THE COMING DAYS, AS EVEN A PASS TO THE SOUTH  
COULD INCREASE MOISTURE AND RAINFALL ACROSS THE SOUTHERN PORTION  
OF THE ISLAND CHAIN. THE GFS REMAINS THE MOST AGGRESSIVE WITH  
THIS SOLUTION, HOWEVER NOTABLY THE 00Z AIFS AND SEVERAL GOOGLE  
DEEPMIND ENSEMBLE MEMBERS TRACK THIS SYSTEM CLOSE ENOUGH TO SEE  
AN UPTICK IN RAINFALL POTENTIAL.  
 
CHENARD  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page