719
FXHW60 PHFO 121303
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
303 AM HST MON OCT 12 2026
SYNOPSIS
LIGHT TO MODERATE BACKGROUND TRADE WINDS WILL PREVAIL, ALLOWING
SEA BREEZES TO DEVELOP IN SHELTERED LEEWARD AREAS TODAY. A BRIEF
INCREASE IN WINDWARD SHOWERS IS EXPECTED MONDAY NIGHT INTO
TUESDAY, ESPECIALLY FOR THE EASTERNMOST ISLANDS. MODERATE TRADE
WINDS WILL BEGIN BUILDING BACK INTO THE REGION DURING THE SECOND
HALF OF THE WEEK, BECOMING LOCALLY BREEZY AGAIN BY THE WEEKEND.
DISCUSSION
CURRENTLY AS OF 3AM HST, RADAR AND SATELLITE SHOWS A MOSTLY TO
PARTLY CLOUDY SKY WITH A FEW ISOLATED LIGHT SHOWERS GOING ON
ACROSS THE STATE. A WEAK LOW IN THE MID AND UPPER LEVELS IS
LOCATED JUST EAST OF THE BIG ISLAND. OVER THE NEXT FEW DAYS, THIS
FEATURE WILL LINGER AND THEN MOVE OFF TO THE NORTHEAST, WITH
LITTLE EFFECT ON ISLAND WEATHER. HOWEVER, AN AREA OF ENHANCED
MOISTURE ASSOCIATED WITH A TROUGH EAST OF THE ISLANDS WILL MAKE
ITS WAY WESTWARD, REACHING THE EASTERN END OF THE STATE LATER
TODAY. AS THIS FEATURE QUICKLY MOVES THROUGH, WINDWARD SHOWERS ARE
ANTICIPATED TO INCREASE, ESPECIALLY FOR THE BIG ISLAND AND MAUI.
THE REMAINING ISLANDS MAY SEE A SLIGHT INCREASE IN WINDWARD AND
MAUKA SHOWERS AS WELL.
BY WEDNESDAY, MODERATE TRADES WILL BUILD BACK INTO THE REGION,
STRENGTHENING TO BECOME LOCALLY BREEZY BY THE END OF THE WEEK.
SHOWERS WILL GENERALLY FAVOR WINDWARD AND MAUKA AREAS THROUGHOUT
THE REST OF THE WEEK, ESPECIALLY DURING THE OVERNIGHT AND MORNING
HOURS. AN ADDITIONAL BAND OF MOISTURE APPROACHING FROM THE EAST
COULD BRING ANOTHER UPTICK IN SHOWERS LATE THIS WEEK INTO NEXT
WEEKEND.
AVIATION
LIGHT TO MODERATE TRADE FLOW WILL TO CONTINUE TODAY. ISOLATED
AFTERNOON CLOUDS AND SHOWERS SHOULD ONCE AGAIN DEVELOP OVER
TERRAIN SHELTERED/LEEWARD AREAS DUE TO THE LIGHT WINDS. HOWEVER,
SHOWER ACTIVITY ACROSS WINDWARD AND MOUNTAIN AREAS WILL BE
LIMITED. A SURFACE TROUGH IS FORECAST TO APPROACH FROM THE EAST
TONIGHT AND PROVIDE AN INCREASE IN SHOWER COVERAGE ALONG WINDWARD
AREAS OF BIG ISLAND. BRIEF PERIODS OF MVFR CEILINGS AND VISIBILITY
MAY OCCUR WITH THIS ACTIVITY. VFR CONDITIONS ELSEWHERE.
NO AIRMETS ARE CURRENTLY IN EFFECT.
MARINE
MODERATE TO LOCALLY FRESH TRADE WINDS CONTINUE THROUGH TUESDAY
BEFORE DECREASING BY MID-WEEK INTO THE LIGHT TO MODERATE RANGE.
SLIGHT DAY TO DAY FLUCTUATIONS ARE EXPECTED, THEN TRADES ARE
EXPECTED TO STRENGTHEN TOWARDS THE END OF THE WEEK AS HIGH
PRESSURE BUILDS NORTH OF THE AREA.
A LONG-PERIOD SOUTH SWELL WILL HOLD THROUGH MONDAY, PRODUCING
ELEVATED SURF ALONG SOUTH AND WEST-FACING SHORES, BUT IT WILL
REMAIN BELOW ADVISORY LEVELS. SOUTH SHORE SURF WILL DECLINE
GRADUALLY TUESDAY INTO WEDNESDAY, BUT A NEW LONG-PERIOD SOUTH
SWELL ARRIVING LATE WEDNESDAY WILL PROVIDE ANOTHER BUMP IN SURF
FOR THURSDAY AND FRIDAY.
A SMALL SMALL, LONG-PERIOD NORTHWEST SWELL WILL ARRIVE THIS
AFTERNOON AND PEAK TUESDAY INTO WEDNESDAY. THIS SWELL IS EXPECTED
TO BOOST NORTH SHORE SURF TO MODERATE LEVELS. A MODERATE MID
PERIOD NORTH- NORTHWEST SWELL IS POSSIBLE BY THE END OF THE WEEK
INTO THE WEEKEND, DEPENDING ON THE EVOLUTION OF A PROJECTED LOW IN
THE NORTH PACIFIC. HOWEVER, CONFIDENCE IS LOW GIVEN DIFFERENCES
IN MODEL SOLUTIONS WITH THIS FEATURE.
SURF ALONG EAST-FACING SHORES WILL REMAIN SMALL AS LOCAL WINDS
REMAIN FAIRLY WEAK WITH ONLY SLIGHT VARIATIONS EACH DAY. SMALL,
MODERATE-PERIOD WEST AND EAST SWELLS GENERATED BY MULTIPLE PACIFIC
TROPICAL CYCLONES CONTINUE TO MOVE THROUGH THE ISLANDS THROUGH
MONDAY.
FIRE WEATHER
LIGHT TO MODERATE TRADE WINDS WILL CONTINUE FOR THE FIRST HALF OF
THE WEEK. DRY AIR WILL BRING RH LEVELS DOWN TO NEAR- CRITICAL
VALUES FOR PARTS OF THE STATE THROUGH THIS AFTERNOON BUT WINDS
WILL BE LIGHT. INVERSION HEIGHTS RANGE FROM 4000-11000 FEET.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...WALSH
AVIATION...THOMAS
MARINE...FOSTER
FIRE WEATHER...WALSH
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