822
FXHW60 PHFO 121322
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
322 AM HST SUN JUL 12 2026
SYNOPSIS
MODERATE TO LOCALLY BREEZY TRADE WINDS WILL PERSIST THROUGH MUCH
OF NEXT WEEK AS HIGH PRESSURE REMAINS NORTH OF THE STATE. WINDWARD
AND MAUKA SHOWERS WILL CONTINUE, WITH A SLIGHT UPTICK IN MOISTURE
POSSIBLE LATE NEXT WEEK, MAINLY NEAR THE BIG ISLAND. TRADES SHOULD
GRADUALLY EASE LATE NEXT WEEK, WITH A DRIER PATTERN POSSIBLE LATE
NEXT WEEKEND.
DISCUSSION
BROAD SURFACE HIGH PRESSURE ANCHORED NORTH OF THE HAWAIIAN
ISLANDS CONTINUES TO DOMINATE THE CENTRAL PACIFIC THROUGH THE NEXT
SEVERAL DAYS, MAINTAINING A MODERATE TO LOCALLY BREEZY TRADE WIND
REGIME. EMBEDDED WITHIN THE TRADES, ISOLATED SHOWERS WILL
CONTINUE TO FAVOR WINDWARD AND MAUKA LOCATIONS OF ALL ISLANDS,
WITH OCCASIONAL SPILLOVER INTO LEEWARD COMMUNITIES. PWAT ANOMALIES
ARE FORECAST TO REMAIN WITHIN ONE STANDARD DEVIATION OF
CLIMATOLOGICAL NORMAL THROUGH MUCH OF THE FORECAST PERIOD.
TOWARD THE END OF NEXT WEEK, SOME MODEL GUIDANCE INDICATES A
MODEST UPTICK IN MOISTURE ASSOCIATED WITH A WEAK SURFACE LOW
PASSING SOUTH OF THE STATE. THIS FEATURE WOULD BRIEFLY RAISE PWAT
ANOMALIES TO AROUND TWO TO THREE STANDARD DEVIATIONS ABOVE NORMAL,
THOUGH ANY INCREASE IN SHOWER ACTIVITY WILL BE CONFINED TO THE
BIG ISLAND BEFORE MOISTURE VALUES RETURN TO NEAR-NORMAL LEVELS.
BEYOND THIS PERIOD, LONGER-RANGE GUIDANCE SUGGESTS THE
AFOREMENTIONED SURFACE RIDGE WILL GRADUALLY SHIFT NORTHEASTWARD
AND WEAKEN AS EARLY AS THE MIDDLE OF NEXT WEEK. ATTENTION THEN
TURNS TO THE DEEP TROPICS, WHERE SOME ENSEMBLE GUIDANCE IS
BEGINNING TO HINT AT POTENTIAL TROPICAL DEVELOPMENT. WHILE IT
REMAINS FAR TOO EARLY TO SPECULATE ON ANY POTENTIAL IMPACTS TO THE
HAWAIIAN ISLANDS, THE SIGNAL BEARS MONITORING IN FUTURE FORECAST
CYCLES.
CONFIDENCE IS SOMEWHAT HIGHER IN THE BROADER PATTERN EVOLUTION,
WITH THE WEAKENING AND EASTWARD RETREAT OF THE HIGH LEADING TO A
GRADUAL EASING OF THE TRADE WINDS LATE NEXT WEEK. SHOWER COVERAGE
SHOULD DECREASE AS WELL, WITH SOME GUIDANCE SUGGESTING A MODEST
DRYING TREND THAT COULD PERSIST INTO THE LATTER END OF THE
WEEKEND. HOWEVER, GIVEN THE EXTENDED FORECAST RANGE, CONFIDENCE
IN THE TIMING AND MAGNITUDE OF THESE CHANGES REMAINS LOW AT THIS
TIME.
AVIATION
OVERALL WEATHER PATTERN CONTINUES TO FAVOR BREEZY TRADES THROUGH
THE WEEKEND. PERIODIC SHOWERS ARE POSSIBLE ACROSS MAINLY WINDWARD
SITES, BRINGING TEMPO MVFR CONDITIONS AS A RESULT, BUT OTHERWISE
EXPECTING MOSTLY VFR CONDITIONS ACROSS THE STATE.
AIRMET SIERRA IS IN EFFECT FOR WINDWARD OF ALL ISLANDS AS A
RESULT OF THE AFOREMENTIONED SHOWER ACTIVITY. THIS MAY CONTINUE
THROUGH THE MORNING AND EVEN INTO THE AFTERNOON HOURS.
AIRMET TANGO ALSO REMAINS IN EFFECT FOR LOW-LEVEL TURBULENCE
DOWNWIND OF TERRAIN, AND IS EXPECTED TO CONTINUE FOR THE NEXT
SEVERAL DAYS AS WE REMAIN UNDER A BREEZY TRADE WIND PATTERN.
MARINE
MAIN CHANGE THIS MORNING WAS TO EXTEND THE SMALL CRAFT ADVISORY
(SCA) ANOTHER 24 HOURS FOR ALL WATERS. A VERY GOOD ASCAT PASS
OVER THE AREA LAST NIGHT SHOWED SCA WINDS OVER A VARIETY OF
COASTAL WATERS. THE VARIOUS HIGH RESOLUTION MODELS INDICATE LITTLE
CHANGE OVER THE NEXT 24 HOURS, SO HAVE CHOSEN TO EXTEND THE SCA
THROUGH MONDAY AFTERNOON. OTHERWISE, THE FORECAST REMAINS VERY
SIMILAR.
A STRONG HIGH PRESSURE SYSTEM REMAINS NORTH OF THE STATE, BRINGING
FRESH TO STRONG TRADE WINDS TO THE AREA. THE TRADES MAY WEAKEN
SLIGHTLY IN A DAY OR TWO, WHICH WILL LIKELY LEAD TO THE SCA BEING
SCALED BACK TO THOSE WINDIER WATERS AND CHANNELS AROUND MAUI
COUNTY AND THE BIG ISLAND.
A SMALL TO MODERATE, LONG-PERIOD SOUTHWEST SWELL (220 DEGREES)
WILL CONTINUE TO FILL IN THROUGH MONDAY, BOOSTING BOOST SURF
OVER THE NEXT FEW DAYS. SURF ALONG EAST-FACING SHORES WILL
REMAIN ROUGH AND CHOPPY THROUGH THE FORECAST PERIOD DUE TO THE
FRESH TO STRONG TRADE WINDS. A SERIES OF SMALL, MODERATE PERIOD
WEST (270 TO 280 DEGREES) SWELLS WILL HOLD OVER THE NEXT FEW DAYS,
FOLLOWED BY A SMALL, LONG-PERIOD WEST- NORTHWEST (280 TO 290
DEGREES) SWELL HEADING INTO MIDWEEK, SOURCED FROM TYPHOON BAVI IN
THE FAR WESTERN PACIFIC. NO SIGNIFICANT NORTH OR NORTHWEST SWELLS
ARE EXPECTED, SO SURF ALONG NORTH-FACING SHORES IS EXPECTED TO
REMAIN FLAT TO TINY.
HIGHER THAN NORMAL HIGH TIDES ARE EXPECTED DUE TO UPCOMING KING
TIDES, AND WITH WATER LEVELS RUNNING SLIGHTLY HIGHER THAN
PREDICTED, MINOR COASTAL FLOODING WILL BE POSSIBLE EACH AFTERNOON
STARTING TOMORROW THROUGH WEDNESDAY. HOWEVER, MINOR COASTAL
FLOODING IS MOST LIKELY TO OCCUR ON MONDAY AND TUESDAY AFTERNOONS.
INTERESTS IMMEDIATELY ALONG THE COASTS IN LOW-LYING OR VULNERABLE
AREAS SHOULD CONTINUE TO MONITOR FORECASTS.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-
DISCUSSION...PIERCE
AVIATION...EVANS
MARINE...M BALLARD
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