604
FXHW60 PHFO 310646
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
846 PM HST SUN AUG 30 2026
SYNOPSIS
BREEZY TRADES WILL CONTINUE THROUGH AT LEAST THE MIDDLE OF THE
WEEK WITH SHOWERS GENERALLY FAVORING WINDWARD AND MAUKA AREAS,
PARTICULARLY DURING THE OVERNIGHT THROUGH EARLY MORNING HOURS EACH
DAY. TROPICAL STORM LOWELL REMAINS OVER 800 MILES ESE OF THE BIG
ISLAND. LATEST FORECAST TRACK HAS LOWELL PASSING SOUTH OF THE BIG
ISLAND LATE WEDNESDAY INTO THURSDAY. HOW CLOSE IT PASSES SOUTH OF
THE BIG ISLAND IS YET TO BE DETERMINED. AT THE VERY LEAST, WE
SHOULD SEE STRONG AND GUSTY TRADE WINDS THURSDAY INTO FRIDAY.
UPDATE
NO MAJOR CHANGES THIS EVENING. FORECAST STILL REMAINS ON TRACK FOR
AN INCREASE OF LOW LEVEL MOISTURE TONIGHT, WHICH WILL BRING SOME
PASSING SHOWERS OVER WINDWARD AND MAUKA AREAS OVER THE NEXT FEW
DAYS. ANY RAINFALL AMOUNTS SHOULD REMAIN ON THE LIGHTER SIDE DUE
TO STABLE CONDITIONS ALOFT. BEYOND WEDNESDAY, THE WEATHER FORECAST
WILL HIGHLY DEPEND ON THE EVENTUAL TRACK OF T.C LOWELL. COMPARED
TO YESTERDAY, THE GLOBAL MODELS SEEM TO BE COMING INTO BETTER
AGREEMENT WITH LOWELL PASSING SOUTH OF THE BIG ISLAND LATE
WEDNESDAY INTO THURSDAY.
PREV DISCUSSION
ISSUED AT 311 PM HST SUN AUG 30 2026
BENIGN TRADE WIND PATTERN THROUGH AT LEAST WEDNESDAY AS STRONG
LONGWAVE RIDGING APPROACHING 594DM REMAINS ANCHORED NEAR 170W
LONGITUDE BEFORE MIGRATING EAST DURING THE LATTER PORTION OF THE
WEEK. THIS IN TURN FAVORS EXPANSIVE SURFACE HIGH PRESSURE IN
MAINTENANCE OF BREEZY TRADES THROUGH THIS TIME. AN UPTICK IN SHOWERS
FOR WINDWARD AND MAUKA IS EXPECTED NEXT WEEK AS MOISTURE ORIGINATING
OFF THE CALIFORNIA COAST ENTRAINS IN THE TRADES, REACHING THE
ISLANDS AROUND WEDNESDAY.
THE TROPICS REMAIN ACTIVE WITH ATTENTION TURNING TOWARD THE FRIDAY
SEPT 4TH TO WEDNESDAY SEPT 9TH PERIOD. DURING THIS TIME, TC LOWELL
AND TC KARINA WILL MAKE THEIR APPROACHES TOWARD THE ISLANDS WITHIN
JUST A COUPLE DAYS OF EACH OTHER. DURING THIS TIME, UNCERTAINTY RUNS
HIGHER THAN NORMAL OWING TO WEAK STEERING FLOW FOLLOWED BY THE
POTENTIAL EMERGENCE OF A CLOSED UPPER LOW NW OF THE ISLANDS THAT
WILL ALTER STEERING FLOW AND INTRODUCE A COMPONENT OF SHEARING AS
WELL. TC LOWELL AND TC KARINA BOTH CARRY POTENTIAL TO COME
PRECARIOUSLY CLOSE TO THE ISLANDS DURING THIS TIME WINDOW. FOR
LOWELL, THE GFS REMAINS ON THE NORTHERN SIDE OF THE SOLUTION
ENVELOPE WHILE THE NEW ECMWF, MACHINE LEARNING GUIDANCE, AND
OFFICIAL NHC FORECAST REMAIN CONSIDERABLY FURTHER SOUTH. THE
FORECAST REMAINS SENSITIVE TO UPPER AIR FEATURES THAT HAVE YET TO
ACTUALLY FORM AND EVOLVE SO CONFIDENCE REMAINS LOW EVEN AS MODEL
CONSENSUS ON A MORE SOUTHERLY TRACK HAS EMERGED. AS TC LOWELL TRACKS
NW, KARINA WILL BE FAST APPROACHING FROM THE EAST WITH A NW TURN
EXPECTED AS WELL. TIMING OF THIS TURN WILL BE KEY AND REPRESENTS THE
PRIMARY FORECAST UNCERTAINTY FOR KARINA WHICH REMAINS ABOUT A WEEK
OUT. CONSULT NHC FOR THE OFFICIAL TRACK AND INTENSITY FORECAST.
AN APPROACH BY LOWELL THAT IS SUFFICIENTLY FAR SOUTH TO PREVENT
DIRECT IMPACTS TO THE ISLANDS WILL STILL BRING ELEVATED HUMIDITY
AND A HIGH LIKELIHOOD OF GUSTY WINDS FOR LABOR DAY WEEKEND.
AVIATION
A STRONG HIGH PRESSURE SYSTEM NORTH OF THE HAWAIIAN ISLANDS WILL
KEEP MODERATE TO BREEZY TRADE WINDS IN THE FORECAST OVER THE NEXT
SEVERAL DAYS. A UNSETTLED BAND OF CLOUDS AND SHOWERS WILL MOVE
INTO THE ISLANDS OVER THE NEXT FEW HOURS, BRINGING PERIODS OF MVFR
CONDITIONS MAINLY ALONG THE WINDWARD MOUNTAIN AREAS THROUGH EARLY
MONDAY MORNING. THESE MVFR CONDITIONS WILL EASE A FEW HOURS AFTER
SUNRISE.
AIRMET SIERRA WAS ISSUED THIS EVENING FOR TEMPO MOUNTAIN
OBSCURATIONS FOR NORTH THROUGH EAST SECTIONS OF ALL ISLANDS DUE TO
INCREASING LOW CLOUD AND SHOWER TRENDS.
AIRMET TANGO REMAINS IN EFFECT FOR MOD LOW LEVEL TURBULENCE SOUTH
THROUGH WEST OF ISLAND MOUNTAINS. THIS TURBULENCE AIRMET WILL
LIKELY CONTINUE FOR THE FORESEEABLE FUTURE.
MARINE
ISSUED AT 311 PM HST SUN AUG 30 2026
A STRONG SURFACE HIGH WILL REMAIN NEARLY STATIONARY FAR NORTH OF
THE HAWAIIAN ISLANDS THIS WEEK. MODERATE TO LOCALLY STRONG TRADE
WINDS WILL PREVAIL THROUGH THE WEEK. TROPICAL CYCLONE LOWELL MAY
MOVE INTO THE HAWAIIAN OFFSHORE WATERS FROM WEDNESDAY INTO THURSDAY.
WIND AND WEATHER IMPACTS AND TIMING FOR THE COASTAL WATERS, INCLUDING
WIND WAVES AND COMBINED SEAS WILL BE DRIVEN BY THE SPEED AND TRACK
OF LOWELL AS IT MOVES TOWARDS THE REGION.
THE CURRENT SOUTH SWELL WILL SLOWLY DECREASE OVER THE NEXT SEVERAL
DAYS. OVERLAPPING SMALL, LONG- AND MEDIUM-PERIOD SOUTH SWELL ENERGY
WILL KEEP SMALL SURF ALONG SOUTH FACING SHORES THROUGH THE WEEK.
THE NEXT BOOST IN SOUTH SWELL ENERGY WILL ARRIVE AND FILL IN FROM
TUESDAY TO WEDNESDAY AT AROUND 2 TO 3 FEET WITH AN 18 SECOND PERIOD.
THIS SWELL WILL PEAK ON WEDNESDAY, JUST BELOW SOUTH SHORE ADVISORY
THRESHOLDS, AND THEN SLOWLY DECLINE THROUGH THE END OF THE WEEK.
TRADE WIND SWELL ENERGY WILL CONTINUE TO KEEP ELEVATED SURF
HEIGHTS ALONG ALL EAST FACING SHORES THROUGH THE COMING WEEK. SURF
ALONG EAST AND SOUTHEAST FACING SHORES COULD BECOME ESPECIALLY
ROUGH AND CHOPPY THURSDAY INTO FRIDAY AS LOWELL PASSES BY TO THE
SOUTH.
FIRE WEATHER
ISSUED AT 311 PM HST SUN AUG 30 2026
BREEZY TRADES CONTINUE THROUGH MIDWEEK AND THEN STRENGTHEN
THURSDAY THROUGH SATURDAY AS TC LOWELL PASSES SOUTH OF THE
ISLANDS. DEWPOINTS INCREASE INTO THE 70S DURING THIS TIME IN
MAINTENANCE OF ELEVATED MIN RH VALUES. THE EXACT TRACK OF TC
LOWELL REMAINS UNCERTAIN AND THUS POTENTIAL FOR MEANINGFUL
RAINFALL REMAINS UNCERTAIN AT THIS TIME. THE INVERSION WILL HOVER
BETWEEN 6K-7KFT THE NEXT COUPLE OF DAYS.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST TUESDAY FOR ALENUIHAHA
CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS-
MAALAEA BAY-PAILOLO CHANNEL.
UPDATE...KINO
DISCUSSION...JVC
AVIATION...BOHLIN
MARINE...TS
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