657
FXHW60 PHFO 230603
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
803 PM HST MON JUN 22 2026
SYNOPSIS
AFTER A DRY DAY MONDAY, WE WILL SEE AN INCREASE IN BOTH MOISTURE
AND TRADE WINDS TUESDAY INTO WEDNESDAY. THIS WILL BRING AN
INCREASE IN SHOWERS, MAINLY WINDWARD AND MAUKA. TRADES WILL
CONTINUE AT MODERATE TO OCCASIONALLY BREEZY LEVELS INTO THE
WEEKEND, WITH THE POTENTIAL FOR A DRIER PERIOD FRIDAY AND
SATURDAY.
SHORT TERM UPDATE
A FEW MINOR ADJUSTMENTS WERE MADE TO POPS TO ACCOUNT FOR CURRENT
TRENDS. PREVIOUS FORECAST IS ON TRACK.
PREV DISCUSSION
ISSUED AT 336 PM HST MON JUN 22 2026
SCATTERED SHOWERS WERE MOVING OVER KAUAI COUNTY THIS AFTERNOON,
WITH ONLY LIGHT ISOLATED SHOWERS ELSEWHERE. SKIES WERE MOSTLY
SUNNY OVER THE MAJORITY OF THE STATE, WITH THE EXCEPTIONS MAINLY
OVER KAUAI COUNTY AND LOWER ELEVATIONS OF THE BIG ISLAND. WINDS
WERE REPRESENTATIVE OF A LIGHT TO MODERATE TRADE FLOW, WITH
SUSTAINED SPEEDS AVERAGING 10 TO 15 MPH, WITH A FEW GUSTS AROUND
25 MPH AND THE TYPICAL WINDY SPOTS.
RELATIVELY LIGHT TRADES AND DRY CONDITIONS WILL GIVE WAY TO
INCREASING WINDS AND MOISTURE TONIGHT INTO TUESDAY AS A SURFACE
TROUGH APPROACHES FROM THE EAST. THIS WILL BRING AN INCREASE IN
SHOWERS, MAINLY WINDWARD AND MAUKA. PW VALUES WILL INCREASE
TUESDAY INTO TUESDAY NIGHT (WITH THE LATEST GUIDANCE COMING IN A
LITTLE LOWER THAN PREVIOUS RUNS).
ALOFT, A WEAK UPPER LEVEL LOW TO OUR NORTHEAST WILL DRIFT
SOUTHWEST AND COME NEAR THE STATE WEDNESDAY INTO WEDNESDAY NIGHT
BEFORE MOVING OFF TO THE NORTHWEST AND THEN WEAKENING THROUGH
SUNDAY. THIS UPPER LOW WILL BRING COOLER AIR ALOFT, ENHANCING
INSTABILITY SLIGHTLY FOR THE COMING WEEK. THIS WILL LEAD TO A
DEEPER SURFACE BOUNDARY AND HIGHER INVERSION, LEADING TO STRONGER
RAIN RATES COMPARED TO THE PAST FEW DAYS. HOWEVER, NO WIDESPREAD
HEAVY RAIN IS FORECAST. THE IMPACT WILL BE MAINLY WINDWARD AND
MAUKA DUE TO THE STRENGTHENING TRADE WINDS.
NORTH OF OUR WEAK UPPER LEVEL LOW, AN UPPER LEVEL RIDGE WILL HELP
KEEP A STRONG SURFACE HIGH POSITIONED TO OUR NORTHEAST, OFF THE
COAST OF THE MAINLAND. THIS WILL KEEP THE TRADES BLOWING A
MODERATE TO OCCASIONALLY BREEZY LEVELS INTO THE WEEKEND. MODELS
INDICATE SOME DRIER AIR APPROACHING FRIDAY AND SATURDAY, REDUCING
THE NUMBER AND STRENGTH OF SHOWERS.
AVIATION
MODERATE TO LOCALLY BREEZY TRADE WINDS EXPECTED THROUGH MIDWEEK.
A TROUGH EAST OF THE STATE MOVING WESTWARD WILL INCREASE SHRA
ACROSS MOST SITES THROUGH WEDNESDAY. MVFR CONDS CAN BE EXPECTED AS
THE TROUGH PASSES THROUGH.
NO AIRMET'S ARE CURRENTLY IN EFFECT, HOWEVER AIRMET SIERRA FOR
MTN OBSC MIGHT BE NEEDED OVERNIGHT THROUGH TOMORROW AS THE TROUGH
MOVES THROUGH.
MARINE
ISSUED AT 336 PM HST MON JUN 22 2026
A WEAK HIGH PRESSURE RIDGE WILL REMAIN NEARLY STATIONARY NORTH OF
THE WATERS MAINTAINING GENTLE TO LOCALLY FRESH TRADE WINDS
THROUGH TUESDAY. HIGH PRESSURE TO THE FAR NORTH-NORTHEAST WILL
STRENGTHEN BY MID-WEEK, CAUSING EASTERLY TRADE WINDS TO GRADUALLY
STRENGTHEN TO MODERATE TO LOCALLY STRONG LEVELS. A SMALL CRAFT
ADVISORY (SCA) MAY NEED TO BE ISSUED FOR THE WINDIER WATERS AND
CHANNELS AROUND MAUI COUNTY AND THE BIG ISLAND AS EARLY AS TUESDAY
NIGHT WITH THE EAST TO WEST PASSAGE OF A LOW-LEVEL TROUGH OVER
THE ISLANDS CONTRIBUTING TO ENHANCED WINDS BEHIND THE FEATURE. THE
TROUGH WILL ALSO BE ACCOMPANIED BY AN INCREASE IN SHOWER ACTIVITY
TUESDAY AND WEDNESDAY. SCA CONDITIONS ARE THEN LIKELY TO CONTINUE
THROUGH THE END OF THE WEEK.
A SERIES OF SMALL TO MODERATE, MEDIUM TO LONG PERIOD SOUTH SWELLS
WILL KEEP SURF ALONG SOUTH-FACING SHORES NEAR SEASONAL AVERAGE
THROUGH THE FORECAST PERIOD. A MODERATE, LONG-PERIOD SWELL
(NEARLY 3 FEET, 15 SECONDS ON BUOY 2) IS GIVING A SLIGHT BOOST TO
SOUTH SHORE SURF THIS AFTERNOON WHICH IS EXPECTED TO CONTINUE
THROUGH TONIGHT BEFORE FADING ON TUESDAY. ANOTHER BOOST IN SOUTH
SWELL IS EXPECTED WEDNESDAY NIGHT INTO THURSDAY BELOW HIGH SURF
ADVISORY LEVELS.
SURF ALONG EAST-FACING SHORES WILL REMAIN SMALL DUE TO THE LACK OF
TRADE WIND ENERGY UPSTREAM OF THE ISLANDS THROUGH TONIGHT. EASTERLY
WIND WAVE LOOKS TO INCREASE TUESDAY INTO THE END OF THE WEEK, REACHING
MODERATE LEVELS AS TRADE WINDS INCREASE. SURF ALONG NORTH-FACING
SHORES WILL REMAIN FLAT TO TINY THROUGH THE FORECAST PERIOD WITH A
POTENTIAL BUMP OF TINY BACKGROUND ENERGY MIDWEEK INTO THURSDAY.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
UPDATE...WALSH
DISCUSSION...PARKER
AVIATION...WALSH
MARINE...QUESADA
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