972
FXHW60 PHFO 121314
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
314 AM HST SUN OCT 12 2025
SYNOPSIS
AN UPPER-LEVEL LOW APPROXIMATELY 800 MILES NORTH OF THE ISLANDS
WILL DIG SOUTH THROUGH MIDWEEK. THIS WILL INCREASE INSTABILITY
AND INTRODUCE A CHANCE FOR HEAVIER SHOWERS AND A FEW
THUNDERSTORMS. EAST TO SOUTHEAST SURFACE WINDS CONTINUE, BECOMING
STRONGER FROM WEDNESDAY INTO NEXT WEEKEND.
DISCUSSION
LOOKING AT RADAR AT 3AM, A FEW SHOWERS ARE MOVING ACROSS THE
REGION. NIGHTTIME MICROPHYSICS SATELLITE IMAGERY INDICATES SOME
HIGH CLOUDS STREAMING IN THE FROM SOUTHWEST. A FEW LOW-LEVEL
CLOUDS ARE ISOLATED IN NATURE AND MOST SPOTS ARE SEEING
RELATIVELY CLEAR SKIES.
A STRONG UPPER-LEVEL LOW DIGGING SOUTH TOWARD THE STATE WILL HELP
DETERMINE OUR WEATHER FOR THE COMING WEEK. AN INCREASE IN LOW-
LEVEL MOSITURE AND INSTABILITY IS EXPECTED AS THE LOW GETS CLOSER.
AS SUCH HEAVIER SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE
TUESDAY AFTERNOON THROUGH THURSDAY. CONDITIONS WILL REMAIN
FAVORABLE FOR THUNDERSTORMS THROUGH AT LEAST FRIDAY. MODELS ARE IN
SOME DISAGREEMENT AS FAR AS TIMING AND PLACEMENT OF THIS LOW.
THIS IS CAUSING SOME UNCERTAINTY IN EXACTLY WHERE AND WHEN WE
COULD SEE HEAVIER SHOWERS AND THUNDERSTORMS. HOWEVER CONFIDENCE IS
INCREASING THAT WE WILL MOST LIKELY SEE SOME HEAVY SHOWERS AND
THUNDERSTORMS OVER AT LEAST THE WESTERN SIDE OF THE STATE. DETAILS
WILL CONTINUE TO BE REFINED IN THE COMING FORECASTS.
AVIATION
LIGHT E-ESE WINDS HAVE RESULTED IN LAND BREEZES KEEPING SKIES
RELATIVELY CLEAR. EXPECT WINDS TO REMAIN LIGHT TODAY WITH SEA
BREEZES DEVELOPING OVER LEEWARD AND INTERIOR LOCATIONS. A FEW
SHRA AND SOME LOW CIGS WITH ISOL MVFR CONDS WILL BE POSSIBLE BUT
OTHERWISE VFR WILL PREVAIL.
NO AIRMETS IN EFFECT.
MARINE
BROAD TROUGHING NORTH OF THE ISLANDS WILL KEEP THE LOCAL PRESSURE
GRADIENT SOMEWHAT WEAK, MAINTAINING MAINLY GENTLE TO MODERATE
TRADE WINDS OVER COASTAL WATERS INTO TUESDAY. THE TROUGH WILL
GRADUALLY FILL IN LATE TUESDAY AND WEDNESDAY, AND BUILDING
SURFACE HIGH PRESSURE NORTH OF 30N WILL DRIVE STRENGTHENING TRADE
WINDS. SMALL CRAFT ADVISORY CONDITIONS MAY DEVELOP OVER THE
TYPICALLY WINDY WATERS AROUND THE BIG ISLAND AND MAUI AS EARLY AS
WEDNESDAY NIGHT AND LIKELY BY THURSDAY. AS TRADES STRENGTHEN, A
DISTURBANCE ALOFT WILL DRIFT SOUTHWARD OVER THE ISLANDS AND BRING
INSTABILITY.
SMALL TO MODERATE NORTHWEST SWELL THIS MORNING WILL GIVE WAY TO A
LONG PERIOD FORERUNNERS OF A NEW NORTHWEST (320 DEG) SWELL BUILDING
LATE TODAY AND TONIGHT. SURF SHOULD PEAK AT HIGH SURF ADVISORY
LEVELS MONDAY AND TUESDAY FOR MOST NORTH AND WEST SHORES FROM
KAUAI TO MAUI. SURF WILL GRADUALLY DECLINE THURSDAY AND FRIDAY,
WITH SOME SMALL NORTHWEST SWELL LINGERING INTO NEXT WEEKEND.
TINY BACKGROUND SOUTH SWELL WILL PREVAIL THROUGH THE WEEK.
A SLIGHT INCREASE TO NEAR SEASONAL NORMAL AS MEDIUM-PERIOD EASTERLY
SWELL FROM A DISTANT TROPICAL CYCLONE MOVES ACROSS THE AREA
TODAY. EAST SHORE SURF WILL BE SMALL TUESDAY, THEN INCREASE AND
BECOME ROUGH DURING THE SECOND PART OF THE WEEK AS TRADE WINDS
BUILD OVER AND UPWIND OF THE ISLANDS.
WATER LEVELS DURING MORNING HIGH TIDES WILL CONTINUE TO GRADUALLY
LOWER DURING THE NEXT COUPLE OF DAYS. WATER LEVELS PEAKED JUST
BELOW THE FLOODING LEVEL AT MOST STATIONS YESTERDAY WITH CONDITIONS
EXPECTED TO BE BORDERLINE AT HIGH TIDE MORNING.
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 7,000 FEET.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...WALSH
AVIATION...WALSH
MARINE...FOSTER
FIRE WEATHER...WALSH
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page