148
FXHW60 PHFO 030157
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
357 PM HST THU OCT 2 2025
SYNOPSIS
GENTLE TO MODERATE EAST-SOUTHEAST WINDS WILL CONTINUE THROUGH
SATURDAY MORNING IN RESPONSE TO AN APPROACHING COLD FRONT IN THE
NORTH CENTRAL PACIFIC, ALLOWING LOCALIZED DAYTIME SEA BREEZES AND
OVERNIGHT LAND BREEZES TO CONTINUE. MODERATE TRADES ARE FORECAST
TO BUILD BACK LATE SATURDAY AND REMAIN INTO EARLY NEXT WEEK AS A
NEW HIGH BUILDS NORTH OF THE STATE.
DISCUSSION
GENTLE TO MODERATE EAST-SOUTHEAST WINDS WILL CONTINUE THROUGH
SATURDAY MORNING IN RESPONSE TO AN APPROACHING COLD FRONT IN THE
NORTH CENTRAL PACIFIC. THE FRONT WILL STALL OUT NORTH OF THE
ISLANDS AND SO WILL NOT HAVE A DIRECT IMPACT ON OUR WEATHER.
SOUNDINGS TAKEN THIS AFTERNOON SHOW RELATIVELY STABLE CONDITIONS,
WITH THE INVERSION BETWEEN 7 AND 8 KFT. CURRENT RADAR AND
SATELLITE DATA SHOW SMALL, ISOLATED SHOWERS MOVING GENERALLY
NORTHWEST THIS AFTERNOON. MOST SHOWERS ARE PASSING NORTH AND SOUTH
OF THE ISLANDS, LIKELY DUE TO DOWNSTREAM PARTIAL BLOCKAGE FROM
THE BIG ISLAND.
THE LIGHT WINDS AND BIG ISLAND BLOCKAGE HAVE ALLOWED SEA BREEZES
AND INTERIOR CLOUD BUILD-UPS AND ISOLATED SHOWERS OVER THE
ISLANDS THIS AFTERNOON. LAND BREEZES WILL CLEAR OUT THE ISLANDS
TONIGHT, FOLLOWED BY A DIURNAL REPEAT FRIDAY AND FRIDAY NIGHT.
DEPENDING ON THE EXACT WIND DIRECTION, DOWNSTREAM CONVERGENCE FROM
ISLAND-MOUNTAINS HAS THE POTENTIAL TO PRODUCE PLUMES OF CLOUDS
AND SHOWERS THAT WOULD EXTEND WEST TO NORTHWEST FROM EACH ISLAND,
AND COULD ANCHOR SHOWERS OVER WINDWARD AND SOUTHEAST SIDES OF THE
SMALLER ISLANDS. THIS COULD OVERRIDE THE LAND BREEZE SUPPRESSION
AT TIMES.
LATEST MODELS INDICATE EASTERLY TRADES WILL BUILD BACK INTO THE
REGION SATURDAY AFTERNOON AND CONTINUE INTO EARLY NEXT WEEK AS A
NEW SURFACE HIGH DEVELOPS AND STRENGTHENS FAR TO THE NORTH OF THE
STATE. HOWEVER, GLOBAL MODELS CONTINUE TO DIFFER REGARDING THE
LOCATION OF A POTENTIAL TROUGH THAT WILL LIKELY DEVELOP NORTH OF
THE ISLANDS BY THE MIDDLE OF NEXT WEEK. THIS RESULTS IN A
RELATIVELY LOW-CONFIDENCE FORECAST FOR WEDNESDAY AND NEXT
THURSDAY.
AVIATION
AN ESE WIND REGIME WITH EMBEDDED SHOWERS WILL CONTINUE THROUGH
TONIGHT AND INTO TOMORROW. TODAY'S WIND FLOW HAS ALSO ALLOWED FOR
SEA BREEZES TO DEVELOP OVER SOME LEEWARD AREAS, BRINGING CLOUDS
AND ISOLATED SHOWERS TO THOSE AREAS. MVFR CONDITIONS WILL BE
POSSIBLE IN ANY SHOWERS THROUGH THE PERIOD. OTHERWISE, VFR WILL
PREVAIL.
LOW LEVEL WIND SHEAR IS POSSIBLE OVER KAHULUI AND NEARBY AREAS
FROM 500 FT. TO THE SURFACE THROUGH THE EVENING DUE TO GUSTY NE
WINDS NEAR THE SURFACE AND WEAKER ESE WINDS ALOFT. THESE
CONDITIONS ARE UNLIKELY TO PERSIST OVERNIGHT AS THE SURFACE WINDS
GRADUALLY WEAKEN AND BECOME VARIABLE.
NO AIRMET'S ARE CURRENTLY IN EFFECT. AIRMET SIERRA COULD BE
ISSUED AS SHOWERS DEVELOP, ESPECIALLY IN THE OVERNIGHT TO EARLY
MORNING HOURS.
MARINE
SURFACE HIGH PRESSURE NORTHEAST OF THE STATE WILL CONTINUE TO
A NORTHEAST TRACK THROUGH FRIDAY AS A FRONT MOVES NORTH OF THE
AREA. LIGHT TO MODERATE EAST SOUTHEAST WINDS HAVE DEVELOPED OVER
THE FORECAST WATERS AND WILL HOLD THROUGH FRIDAY GIVING WAY TO
LOCALIZED LAND AND SEABREEZES OVER LEEWARD WATERS. HIGH PRESSURE
WILL BUILD IN FROM THE NORTHWEST ALLOWING MODERATE TO LOCALLY
FRESH TRADE WINDS TO RETURN SATURDAY THROUGH SUNDAY. A TROUGH MAY
DEVELOP NORTHEAST OF THE STATE EARLY NEXT WEEK, WEAKENING WINDS
TO LIGHT AND VARIABLE.
A SMALL MEDIUM TO LONG PERIOD NORTHWEST (310-320 DEG) SWELL FROM
TROPICAL CYCLONE NEOGURI HAS PEAKED AND WILL DECLINE THROUGH
FRIDAY. A MODERATE, MEDIUM PERIOD NORTH NORTHWEST (330 DEG) SWELL
GENERATED FROM THE CURRENT LOW TRACKING ACROSS THE NORTHWEST
PACIFIC IS EXPECTED TO FILL IN ON SATURDAY, PEAK SUNDAY JUST BELOW
HIGH SURF ADVISORY (HSA) CRITERIA FOR NORTH FACING SHORES, AND
SLOWLY FADE INTO EARLY NEXT WEEK. ANOTHER SMALL MEDIUM TO LONG
PERIOD SWELL FROM THE NORTHWEST (320 DEG) IS EXPECTED TO FILL IN
MONDAY, PEAK TUESDAY AND DECLINE THROUGH THE MIDDLE OF NEXT WEEK.
THE CURRENT SMALL, LONG PERIOD SOUTHWEST (210 DEG) SWELL WILL
CONTINUE TO BUILD THROUGH TONIGHT PEAK FRIDAY BEFORE SLOWLY
DECLINING INTO EARLY NEXT WEEK. ANOTHER SMALL, LONG PERIOD
SOUTHWEST SWELL MAY ARRIVE LATE SUNDAY AND BUILD INTO EARLY NEXT
WEEK BEFORE SUBSIDING. SURF ALONG EAST- FACING SHORES WILL MAINLY
REMAIN BELOW AVERAGE INTO EARLY NEXT WEEK WITH THE A SLIGHT BOOST
SATURDAY INTO SUNDAY AS MODERATE TO FRESH TRADES BRIEFLY RETURN.
FIRE WEATHER
WIND SPEEDS WILL REMAIN BELOW CRITICAL FIRE WEATHER THRESHOLDS
FOR THE NEXT SEVEN DAYS. TEMPERATURE INVERSION HEIGHTS ACROSS THE
STATE WILL RANGE FROM 7,000 TO 8,500 FEET FOR THE REMAINDER OF
TODAY AND FRIDAY.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...PARKER/THOMAS
AVIATION...TROTTER/FARRIS
MARINE...ALMANZA
FIRE WEATHER...PARKER/THOMAS
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