717
FXHW60 PHFO 301343
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
343 AM HST MON JUN 30 2025
SYNOPSIS
LIGHT TRADES WILL PREVAIL AND VEER EAST-SOUTHEAST SLIGHTLY
THROUGH THE NEXT COUPLE OF DAYS IN RESPONSE TO BROAD AND WEAK
SURFACE TROUGH. SHOWER ACTIVITY WILL PRIMARILY IMPACT TYPICAL
WINDWARD AND MAUKA AREAS, HOWEVER LOCALIZED SEA BREEZES WILL
INCREASE SHOWERS TO LEEWARD AND INTERIOR AREAS THROUGHOUT TODAY.
TOWARD MID-WEEK, TRADES SHIFT BACK EASTERLY, GRADUALLY INCREASING
IN STRENGTH INTO THE WEEKEND.
DISCUSSION
A BROAD, POSITIVE-TILTED SURFACE TROUGH PASSING TO THE NORTH OF
THE ISLANDS WILL BE THE CULPRIT TO WEAKER TRADES THE NEXT FEW
DAYS. AS TRADES DECREASE IN STRENGTH AND VEER SLIGHTLY EAST-
SOUTHEAST, EXPECT LAND-SEA BREEZES TO DEVELOP ACROSS SELECT AREAS
AS A RESPONSE. ADDITIONALLY, AS THE TROUGH REMAINS PRESENT IN
VICINITY OF THE ISLANDS, SHOWER ACTIVITY WILL LIKELY INCREASE AS
WELL, PREDOMINATELY ACROSS WINDWARD AND MAUKA AREAS, BUT MAY STRAY
INTO LEEWARD AND INTERIOR AREAS AS WELL WHERE AFTERNOON SEA
BREEZES DEVELOP IN THE LIGHTER WIND FLOW. ANY SIGNIFICANT INCREASE
IN SHOWER ACTIVITY WILL BE HINDERED BY A MIDLEVEL INVERSION AT
AROUND 8000 FEET.
AS THE AFOREMENTIONED TROUGH EXITS BY THE MID-WEEK, AS WILL THE
INCREASED SHOWER ACTIVITY. THE SURFACE HIGH WELL NORTHEAST OF THE
ISLANDS WILL GRADUALLY BUILD, LEADING TO A RETURN OF MODERATE TO
LOCALLY BREEZY TRADES ACROSS THE STATE. DURING THIS TIME, EXPECT
DRIER CONDITIONS AND LESS CLOUD COVERAGE, HOWEVER, POCKETS OF
MOISTURE ESCORTED BY THESE TRADES WILL LEAD TO PERIODIC SHOWERS
ACROSS WINDWARD AND MAUKA AREAS.
LATEST MODEL GUIDANCE OF THE GFS AND EURO REMAINS IN GOOD
AGREEMENT THAT TRADES WILL STEADILY INCREASE ACROSS THE STATE TO
BREEZY TO LOCALLY STRONG INTO THE WEEKEND THROUGH EARLY NEXT WEEK.
WHILE STRONGER TRADES TYPICALLY RESULT IN AN INCREASE IN PASSING
SHOWERS, LATEST GUIDANCE SUGGESTS THAT SHOWER ACTIVITY WILL REMAIN
MODEST AT BEST, GIVEN ATMOSPHERIC STABILITY ALOFT.
AVIATION
CLOUDS AND SHOWERS ARE EXPECTED TO PREVAIL THROUGH MUCH OF THE DAY
OVER LEEWARD AND INTERIOR SIDES OF THE ISLANDS DUE TO SEA BREEZE
CONVERGENCE. OTHERWISE, EXPECT PASSING SHOWERS OVER TYPICAL
WINDWARD AND MOUNTAIN AREAS. BRIEF PERIODS OF MVFR CONDITIONS
LIKELY WITH ANY SHOWERS, BUT OVERALL VFR CONDITIONS SHOULD
PREVAIL.
NO AIRMETS ARE IN EFFECT AT THIS TIME.
MARINE
A TROUGH LOCATED FAR TO THE NORTH ALONG WITH WEAKENING SURFACE
HIGH PRESSURE TO THE NORTHEAST WILL CONTRIBUTE TO WEAKENING TRADE
WINDS OVER THE NEXT FEW DAYS. A SLIGHT SOUTHERLY COMPONENT TO THE
WINDS IS EXPECTED TODAY AS THE TROUGH TO OUR NORTH LINGERS. WINDS
SHOULD THEN BECOME EASTERLY AND REMAIN IN THE MODERATE TO LOCALLY
FRESH RANGE TUESDAY THROUGH MIDWEEK AS THE TROUGH WEAKENS AND
DISSIPATES. TRADE WINDS SHOULD STRENGTHEN BY INDEPENDENCE DAY INTO
THE WEEKEND AS HIGH PRESSURE BUILDS TO THE NORTH.
SURF ALONG SOUTH FACING SHORES WILL SEE A SMALL, LONG-PERIOD SOUTH
SWELL FILL IN AND HOLD TODAY AND TOMORROW WITH SURF PEAKING
NEAR THE SUMMERTIME AVERAGE. SURF HEIGHTS WILL THEN GRADUALLY
LOWER LATE TOMORROW THROUGH THE WEEK AS THE SWELL SLOWLY DECLINES,
HOWEVER SMALL PULSES WILL KEEP SURF HEIGHTS FROM FALLING FLAT. A
SMALLER LONG- PERIOD SOUTH SWELL COULD MOVE THROUGH TOWARD THE END
OF THIS WEEK FOR A SLIGHT BOOST TO SOUTH SHORE SURF.
SURF ALONG EAST SHORES WILL REMAIN SMALL OVER THE NEXT SEVERAL
DAYS DUE TO THE TRADE WINDS WEAKENING, THEN COULD INCREASE TOWARDS
THE END OF THE WEEK AS TRADE WINDS STRENGTHEN. SURF ALONG NORTH
FACING SHORES WILL REMAIN SEASONALLY TINY THROUGH THE WEEK.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...PIERCE
AVIATION...PIERCE
MARINE...TSAMOUS
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