434  
FXHW60 PHFO 130255 CCA  
AFDHFO  
 
AREA FORECAST DISCUSSION...CORRECTED  
NATIONAL WEATHER SERVICE HONOLULU HI  
455 PM HST SUN OCT 12 2025  
   
SYNOPSIS  
 
AN UPPER-LEVEL LOW CENTERED SEVERAL HUNDRED MILES NORTH OF THE  
STATE WILL CONTINUE TO MOVE SOUTH THROUGH MIDWEEK, THEN WEAKEN AND  
SLIDE OFF TO THE WEST. THIS WILL BRING A CHANCE FOR HEAVIER  
SHOWERS AND A FEW THUNDERSTORMS FROM WEDNESDAY INTO FRIDAY  
EVENING. RELATIVELY LIGHT SOUTHEAST SURFACE WINDS CONTINUE THROUGH  
TUESDAY, WITH STRONGER TRADES KICKING IN WEDNESDAY INTO LASTING  
INTO NEXT WEEKEND.  
 
 
   
DISCUSSION  
 
ANOTHER AFTERNOON OF SEA BREEZES AND ISOLATED SHOWERS MAINLY IN  
LEEWARD AREAS IS WELL UNDERWAY. THAT PATTERN WILL GENERALLY  
CONTINUE THROUGH TUESDAY. THE LARGEST AREA OF SHOWERS AS OF 3 PM  
HST WAS OVER SOUTHWEST KAUAI. IN ADDITION, A BAND OF HIGHER  
CLOUDS, ASSOCIATED WITH THE ENTRANCE REGION OF AN UPPER LEVEL JET,  
WAS MOVING SW TO NE.  
 
A STRONG UPPER LEVEL LOW AND ITS SURFACE REFLECTION WILL CONTINUE  
TO MOVE SOUTH THROUGH WEDNESDAY AFTERNOON, REACHING THE WESTERN  
ISLANDS (IT WILL BE CENTERED ROUGHLY OVERHEAD) BEFORE SLIDING OFF  
TO THE WEST AND WEAKENING LATE THIS WEEK AND INTO NEXT WEEKEND.  
THIS WILL BRING COOLER AIR ALOFT, INCREASING INSTABILITY AND THE  
CHANCE FOR STRONGER SHOWERS AND THUNDERSTORMS, ESPECIALLY  
WEDNESDAY THROUGH FRIDAY EVENING. WE HAVE GONE AHEAD AND  
INTRODUCED THUNDERSTORMS INTO THE FORECAST AS CONFIDENCE IS HIGH  
THAT THEY WILL OCCUR. THE MOST LIKELY AREA IS THE WESTERN PART OF  
THE STATE, BUT WE CAN'T RULE OUT STORMS IN THE EAST AT THIS TIME.  
 
THE OTHER SIGNIFICANT CHANGE THIS COMING WEEK WILL BE THE SURFACE  
WINDS. RELATIVELY LIGHT SOUTHEAST WINDS WILL GIVE WAY TO EASTERLY  
TRADES WEDNESDAY. WIND SPEEDS WILL INCREASE, ESPECIALLY IN THE  
USUAL TOPOGRAPHICALLY DRIVEN AREAS STRAIGHTS. SMALL CRAFT  
ADVISORIES MAY BE NEEDED BEGINNING THURSDAY.  
 
 
   
AVIATION  
 
LIGHT E TO ESE WINDS ARE PREVAILING ACROSS THE STATE, WHICH HAS  
RESULTED IN LOCALIZED SEA BREEZES DURING THE DAY. LOW CLOUDS AND  
SHOWERS REMAIN LIMITED OVERALL, THOUGH SOME LOW CLOUDS AND SHOWERS  
WILL REMAIN POSSIBLE THROUGH EARLY EVENING OVER ISLAND INTERIORS  
AND SELECT LEEWARD LOCATIONS. VFR FLIGHT CONDITIONS ARE EXPECTED  
TO PREVAIL AT MOST LOCATIONS. MEANWHILE, AN UPPER JET IS PRODUCING  
A BAND OF HIGH CLOUDS STREAMING OVER THE CENTRAL AND EASTERN  
ISLANDS. THIS JET IS EXPECTED TO WEAKEN AND PUSH EAST OF THE AREA  
THROUGH TONIGHT, SO ANTICIPATE THAT HIGH CLOUD COVER WILL DIMINISH  
BY EARLY MONDAY.  
 
ANOTHER DAY OF LIGHT BACKGROUND WINDS AND DAYTIME SEA BREEZES IS  
EXPECTED ON MONDAY, INCREASING INTERIOR CLOUDS AND SHOWERS DURING  
THE DAY. OVERNIGHT, LAND BREEZES ARE FORECAST TO DIMINISH CLOUD  
COVER OVER THE ISLANDS.  
 
THERE ARE CURRENTLY NO AIRMETS IN EFFECT, AND NONE ARE  
ANTICIPATED AT THIS TIME.  
 
 
   
MARINE  
 
A TROUGH NORTH OF THE AREA WILL SETTLE IN THE PROXIMITY OF THE  
ISLANDS THE NEXT COUPLE OF DAYS. TROUGHING WILL LIKELY LAY ACROSS  
THE FAR WEST WATERS AND, AS ENERGY FROM THE NORTH DIVES SOUTH INTO  
THE TROUGH, THE CHANCES FOR MID TO LATE WEEK WESTERN WATER ISOLATED  
TO SCATTERED THUNDERSTORMS WILL INCREASE. SLIGHTLY STRENGTHENING  
SURFACE HIGH PRESSURE CENTERED AROUND A THOUSAND NAUTICAL MILES  
NORTHEAST OF THE STATE WILL PRODUCE A TIGHT ENOUGH DOWNSTREAM  
PRESSURE GRADIENT BY WEDNESDAY TO RESULT IN MORE WATER-WIDE  
MODERATE TRADE WINDS.  
 
LONG PERIOD FORERUNNERS FROM AN APPROACHING NORTHWEST (320  
DEGREE) SWELL REACHED THE OFFSHORE 51001 AND 51101 BUOYS LATE THIS  
MORNING. THIS HAS A MODERATE SIZE, LONG PERIOD SWELL REACHING  
KAUAI AND OAHU THIS EVENING, MAUI AROUND MIDNIGHT MONDAY. SWELL  
WILL FILL IN AROUND ALL ISLANDS DURING THE OVERNIGHT HOURS AND  
PRODUCE ADVISORY LEVEL SURF ALONG MANY NORTH AND WEST-FACING  
SHORES OF THE SMALLER ISLANDS BY LATE MONDAY MORNING. A HIGH SURF  
ADVISORY WILL BE IN EFFECT FROM MONDAY MORNING THROUGH TUESDAY  
AFTERNOON TO ACCOUNT FOR OVER DOUBLE HEAD HIGH SURF THAT SHOULD  
PEAK ALONG MANY NORTH AND WEST-FACING SHORES EARLY TUESDAY. SURF  
WILL BEGIN TO GRADUALLY FALL FROM TUESDAY NIGHT THROUGH THURSDAY.  
 
A SERIES OF VERY SMALL, MEDIUM PERIOD SOUTHERN SWELL IMPULSES  
COMING FROM A COUPLE OF FAST-MOVING SOUTHERN GALES PASSING SOUTH  
OF NEW ZEALAND WILL PASS THROUGH THIS WEEK.  
 
EAST-FACING SHORE WIND WAVE CHOP WILL BE SMALL THE NEXT COUPLE OF  
DAYS. MORE ROUGH SURF WILL OCCUR LATER THIS WEEK AS TRADES BUILD  
OVER AND UPWIND OF THE ISLANDS.  
 
WATER LEVELS WILL CONTINUE TO GRADUALLY LOWER THROUGH MONDAY.  
THERE MAY BE SOME MINOR FLOODING WITHIN LOW LAYING AREAS DURING  
MONDAY'S HIGH TIDE.  
 
 
   
FIRE WEATHER  
 
LIGHT WINDS AND ISOLATED SHOWERS WILL HELP MAINTAIN FIRE WEATHER  
BELOW CRITICAL THRESHOLDS FOR THE NEXT SEVERAL DAYS. INVERSION  
HEIGHTS WILL RANGE FROM 6,000 TO 8,000 FEET.  
 
 
   
HFO WATCHES/WARNINGS/ADVISORIES  
 
HIGH SURF ADVISORY FROM 6 AM MONDAY TO 6 PM HST TUESDAY FOR  
NIIHAU-KAUAI LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-MAUI  
WINDWARD WEST-KAUAI NORTH-MOLOKAI WINDWARD-MOLOKAI NORTH-MOLOKAI  
WEST-MAUI CENTRAL VALLEY NORTH-WINDWARD HALEAKALA.  
 
 
 
 
 
DISCUSSION...PARKER  
AVIATION...VAUGHAN  
MARINE...BLOOD  
FIRE WEATHER...PARKER  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab HI Page
Main Text Page