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FXHW60 PHFO 050632
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
832 PM HST TUE AUG 4 2026
SYNOPSIS
RELATIVELY WEAK TRADES WILL CONTINUE THROUGH FRIDAY, WITH
INCREASING WIND SPEEDS THIS WEEKEND. AN UPPER LOW AND MIDLEVEL
TROUGH WILL BRING AN INCREASED CHANCE OF SHOWERS TO THE WESTERN
END OF THE STATE OVER THE NEXT FEW DAYS. SHOWERS WILL SHIFT TO
THE EASTERN END OF THE STATE THIS WEEKEND AS AN AREA OF TROPICAL
MOISTURE PASSES BY.
SHORT TERM UPDATE
ISSUED AT 830 PM HST TUE AUG 4 2026
SOME TWEAKS HAVE BEEN MADE TO THE FORECAST THIS EVENING TO BETTER
ALIGN WITH CURRENT RADAR AND SATELLITE TRENDS AND HI-RES GUIDANCE.
HOWEVER, THE OVERALL FORECAST PHILOSOPHY REMAINS UNCHANGED. HIGH
CLOUDS CONTINUE TO STREAM OVER THE STATE, ASSOCIATED WITH THE UPPER
LOW AND MID-LEVEL TROUGH NEAR THE WESTERN ISLANDS. SHOWERS HAVE BEEN
RELATIVELY LIGHT OVER THE LAST SIX HOURS ACROSS STATE. THE BEST
CHANCES FOR SHOWERS DURING THE OVERNIGHT PERIOD TONIGHT WILL BE
ACROSS WINDWARD AND MAUKA SECTIONS OF THE ISLANDS, ESPECIALLY OVER
KAUAI AND OAHU WHICH ARE LOCATED CLOSER TO THE DISTURBANCE ALOFT.
PREV DISCUSSION
ISSUED AT 328 PM HST TUE AUG 4 2026
AN UPPER LOW TO THE WEST AND ASSOCIATED MIDLEVEL TROUGH WILL
LINGER OVER THE NEXT COUPLE OF DAYS AND ENHANCE INCOMING TRADE
WIND SHOWERS, PARTICULARLY ACROSS THE WESTERN HALF OF THE STATE.
COOLING ALOFT ACROSS THE WEST HAS ERODED THE TRADE WIND INVERSION
WITH 00Z SOUNDINGS SHOW A WEAKER AND ELEVATED INVERSION AT LIHUE
COMPARED TO HILO. THE UPPER LOW IS FORECAST TO LIFT AWAY TO THE
NORTH ON FRIDAY RETURNING MORE STABLE CONDITIONS TO THE AREA.
TRADES WILL BE WEAKER THAN AVERAGE THROUGH THURSDAY AS THE REMNANT
OF FORMER TROPICAL CYCLONE GENEVIEVE LINGERS BETWEEN THE
SUBTROPICAL HIGH AND HAWAII. AS A RESULT, TRADES WILL BE WEAK AND
LOCALIZED SEA BREEZES WILL BRING INTERIOR AND LEEWARD CLOUD BUILD
UPS EACH AFTERNOON. ACROSS KAUAI AND OAHU, SCATTERED SHOWERS MAY
DEVELOP DURING THE AFTERNOONS DUE TO THE INSTABILITY AND LOW LEVEL
MOISTURE FROM THE UPPER LOW/TROUGH DESCRIBED EARLIER. TRADES WILL
INCREASE THIS WEEKEND, DOING AWAY WITH MOST OF THE SEA BREEZE
EFFECTS.
THE WEEKEND GUIDANCE SUGGESTS A PLUME OF MOISTURE COMING EITHER
OVER OR VERY CLOSE TO MAUI AND BIG ISLAND. WHILE MOST OF THE PLUME
WILL PASS SOUTH OF THE AREA, THE NORTHERN PERIPHERY OF IT IS
EXPECTED TO SKIRT BY AND BRING ADDITIONAL SHOWERS TO WINDWARD
SIDES OF BOTH ISLANDS.
AVIATION
ISSUED AT 830 PM HST TUE AUG 4 2026
A WEAK HIGH PRESSURE RIDGE FAR NORTH OF THE STATE WILL KEEP
GENTLE TRADE WINDS IN THE FORECAST. BRIEF PERIODS OF SHOWERS WILL
FAVOR WINDWARD MOUNTAIN SLOPES IN THE OVERNIGHT TO EARLY MORNING
HOURS. DURING THE DAY TIME A HYBRID TRADE WIND WITH SEA BREEZES
ALONG LEEWARD MOUNTAIN SLOPES WILL PRODUCE A FEW STRAY AFTERNOON
TO EARLY EVENING SHOWERS OVER SOUTH AND WEST SLOPES OF EACH ISLAND.
AIRMET SIERRA IN EFFECT FOR MOUNTAIN OBSCURATION ABOVE 020 FOR THE
ENTIRE ISLAND OF KAUAI AND FOR WINDWARD MOUNTAIN AREAS OF OAHU
AND MOLOKAI.
AIRMET TANGO MAY BE ISSUED LATER TONIGHT DUE TO UPPER LEVEL
TURBULENCE AS AN UPPER LEVEL LOW AND ASSOCIATED SUBTROPICAL JET
STREAM APPROACHES KAUAI FROM THE NORTHWEST.
MARINE
ISSUED AT 830 PM HST TUE AUG 4 2026
THE REMNANTS OF FORMER TROPICAL CYCLONE GENEVIEVE ARE NEARLY 900
MILES NORTHEAST OF THE ISLANDS THIS EVENING, AND CONTINUE TO LIFT
NORTHWARD AND WEAKEN. A WEST TO EAST ORIENTED FRONT REMAINS WELL
NORTH OF THE ISLANDS. THESE SYSTEMS ARE HELPING TO LIMIT TRADE
WIND SPEEDS ACROSS THE ISLANDS. AS THEY DISSIPATE AND MOVE AWAY
FROM THE ISLANDS, HIGH PRESSURE NORTH OF THE ISLANDS WILL HELP
TRADES TO RESTRENGTHEN TO LOCALLY BREEZY LEVELS BY THE END OF THE
WEEK. THIS COULD THEN BRING SOME SMALL CRAFT ADVISORY LEVEL WINDS
TO THE MORE TYPICAL WINDIER AREAS LATE IN THE WEEK OR OVER THE
WEEKEND.
SURF ALONG SOUTH-FACING SHORES WILL REMAIN BELOW SEASONAL AVERAGES
THROUGH MUCH OF THIS WEEK, THOUGH OCCASIONAL SMALL FLUCTUATIONS
CAN BE EXPECTED AS SMALL BACKGROUND SWELLS MOVE THROUGH. BY THIS
SATURDAY, A SMALL, LONG PERIOD SOUTH SWELL IS EXPECTED TO ARRIVE,
FOLLOWED BY A SERIES OF REINFORCING SOUTH SWELLS THAT WILL BOOST
SURF HEIGHTS TO NEAR OR ABOVE SEASONAL AVERAGES INTO NEXT WEEK.
SMALL, MEDIUM PERIOD EASTERLY SWELL GENERATED FROM FORMER TROPICAL
CYCLONE GENEVIEVE CONTINUES TO LINGER, BUT WILL GRADUALLY EASE
FOR THE NEXT COUPLE OF DAYS. CHOPPY CONDITIONS WILL REMAIN, GENERATED
BY THE MODERATE TRADE WINDS.
SURF ALONG NORTH FACING AND WEST SHORES WILL REMAIN FLAT TO TINY
THROUGH THE FORECAST PERIOD, EXCEPT FOR AREAS EXPOSED TO THE EASTERLY
TRADE WRAP.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM UPDATE...VAUGHAN
DISCUSSION...FOSTER
AVIATION...BOHLIN
MARINE...THOMAS
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