823
FXHW60 PHFO 090125
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
325 PM HST SAT MAR 8 2025
SYNOPSIS
STRONG TRADES CONTINUE THROUGH MID-WEEK BEFORE EASING SLIGHTLY IN
RESPONSE TO UPSTREAM TROUGHING LATER NEXT WEEK. EXPECT PERIODS OF
WINDWARD AND MAUKA SHOWERS DURING THIS TIME, PARTICULARLY
OVERNIGHT AND DURING THE EARLY MORNING.
DISCUSSION
THE PROMINENT FEATURE ON REGIONAL SATELLITE IMAGERY REMAINS TO BE
THE LEFTOVER FRONTAL BAND CURRENTLY POSITIONED AROUND 300 MILES
NORTH OF KAUAI. GOES SATELLITE ESTIMATES SUGGEST SATURATION THROUGH
THE LOWEST 10KFT OR SO WITHIN THIS BAND AS IT IS FORCED SOUTH TOWARD
THE STATE BY RAPIDLY-BUILDING HIGH PRESSURE, EVENTUALLY REACHING
KAUAI EARLY SUNDAY MORNING. IN THE MEANTIME, STRONG TRADES WILL
DELIVER SCATTERED SHOWERS INTO WINDWARD AND MAUKA AREAS, THOUGH
SHOWER INTENSITY WILL BE CAPPED BY A STRENGTHENING INVERSION AVERAGING
ABOUT 7KFT OVER THE STATE. INCREASING SHOWERS ASSOCIATED WITH THE
APPROACHING REMNANT FRONT WILL REACH KAUAI EARLY SUNDAY, OAHU DURING
MIDDAY, AND THE EASTERN HALF OF THE STATE SUNDAY NIGHT INTO MONDAY.
DURING THIS TIME, EXPECT AN EXPANSION OF SHOWER COVERAGE AND A MODEST
INCREASE IN INTENSITY ALONG A RELATIVELY DEEP MOISTURE AXIS, WHICH
SUPPORTING FREQUENT LEEWARD PENETRATION OF SHOWERS CARRIED BY THE
ALREADY STRONG TRADES.
GLOBAL MODELS CONTINUE TO INDICATE STOUT LOW-LEVEL DRY ADVECTION
IN THE WAKE OF THE PASSING FRONTAL BAND ON MONDAY WITH THE INVERSION
POTENTIALLY CRASHING TO 5KFT OR EVEN LOWER BY THE END OF THE DAY.
COUPLED WITH THE STRENGTHENING GRADIENT AS 1030+MB HIGH PRESSURE
BUILDS TOWARD 30N, THE SHALLOW INVERSION AND FORCING FOR DESCENT
WITHIN THE BOUNDARY LAYER COULD LEAD TO SOME OVERACHIEVING WIND
GUSTS ON MONDAY AFTERNOON THAT COULD APPROACH THE ADVISORY THRESHOLD.
THE GRADIENT REACHES PEAK INTENSITY ON TUESDAY, THOUGH IT IS MODELED
TO OCCUR COINCIDENT WITH THE RETURN OF INCREASING MOISTURE EMBEDDED
IN THE TRADES WHICH MAY COMPROMISE HIGHER END WIND GUST POTENTIAL
AS THE INVERSION LIFTS AND WEAKENS. ALL TOLD, BORDERLINE WIND ADVISORY
CONDITIONS ARE LIKELY MONDAY AFTERNOON THROUGH TUESDAY. STRONG TRADES
HOLD THROUGH MID-WEEK, EASING THEREAFTER IN RESPONSE TO A DEVELOPING
SURFACE TROUGH WEST OF THE STATE.
AVIATION
BREEZY TO LOCALLY STRONG TRADE WINDS WILL PERSIST OVER THE NEXT
SEVERAL DAYS. BATCHES OF MOISTURE CAUGHT UP IN THE TRADES WILL
DELIVER PERIODS OF MVFR CONDITIONS TO WINDWARD AREAS OVER THE NEXT
24 HOURS. LOOKING UPSTREAM ON VISIBLE SATELLITE IMAGERY, LOWER
CEILINGS AND SHOWERS WILL LIKELY BE CONCENTRATED ACROSS THE CENTRAL
ISLANDS (OAHU THROUGH MAUI) THROUGH THE REST OF THIS AFTERNOON
AND EVENING. THEN A FRONTAL BOUNDARY TO THE NORTH OF KAUAI WILL
MOVE SOUTH OVERNIGHT AND BRING ANOTHER ROUND OF LOWER CEILINGS AND
SHOWERS TO KAUAI AND OAHU BY TOMORROW MORNING. OTHERWISE, VFR
CONDITIONS SHOULD GENERALLY PREVAIL.
AIRMET SIERRA IS IN EFFECT FOR TEMPO MOUNTAIN OBSCURATION ALONG
WINDWARD AREAS AS LOW CLOUDS AND SHOWERS MOVE IN ON THE TRADES.
THIS AIRMET WILL LIKELY NEED TO BE EXTENDED FOR AT LEAST A PORTION
OF THE ISLAND CHAIN THROUGH TOMORROW MORNING.
AIRMET TANGO REMAINS IN EFFECT FOR MODERATE LOW-LEVEL TURBULENCE
OVER AND DOWNWIND OF ISLAND TERRAIN. THIS AIRMET WILL LIKELY
CONTINUE OVER THE NEXT SEVERAL DAYS.
MARINE
A SERIES OF STRONG HIGHS TO OUR NORTH WILL MAINTAIN FRESH TO STRONG
TRADE WINDS FOR ALL ZONES THROUGH MONDAY. BEGINNING MONDAY NIGHT,
WINDS ARE EXPECTED TO INCREASE FURTHER INTO THE STRONG TO NEAR-GALE
RANGE THROUGH THE MIDDLE OF THE WEEK, WITH GALES POSSIBLE FOR THE
WINDIER WATERS AND CHANNELS AROUND MAUI AND THE BIG ISLAND. THE SMALL
CRAFT ADVISORY HAS BEEN EXTENDED THROUGH MONDAY FOR ALL HAWAIIAN
WATERS DUE TO THE STRONG WINDS AND ELEVATED SEAS, AND WILL LIKELY
BE EXTENDED OR EVEN UPGRADED FOR SOME ZONES EARLY NEXT WEEK.
SURF ALONG NORTH AND WEST FACING SHORES WILL REMAIN ABOVE ADVISORY
LEVELS THROUGH THIS EVENING AND LIKELY THROUGH THE NIGHT AS THE
CURRENT MODERATE, MEDIUM- TO LONG-PERIOD NORTHWEST (310-330 DEGREE)
SWELL HOLDS NEAR ITS AFTERNOON PEAK. THE HIGH SURF ADVISORY HAS
BEEN EXTENDED FOR MOST NORTH AND WEST FACING SHORES OF THE SMALLER
ISLANDS THROUGH TONIGHT, DUE TO SWELL HEIGHTS AT THE NEARSHORE BUOYS
LOOKING TO BE SLOW TO DECLINE OVER THE NEXT SEVERAL HOURS. THIS SWELL
WILL GRADUALLY VEER TOWARD THE NORTH-NORTHWEST AS IT LOWERS THROUGH
EARLY NEXT WEEK.
SURF ALONG EAST-FACING SHORES WILL REMAIN ROUGH INTO NEXT WEEK DUE
TO THE PERSISTENT FRESH TO LOCALLY STRONG TRADE FLOW OVER AND
UPSTREAM OF THE ISLANDS. TRADES COULD POSSIBLY STRENGTHEN EARLY
NEXT WEEK, WHICH WOULD FURTHER INCREASE THE WINDSWELL THROUGH AT
LEAST MIDWEEK.
SURF ALONG SOUTH-FACING SHORES WILL REMAIN SMALL WITH MAINLY SOME
WRAP AROUND WIND SWELL FOR SELECT EXPOSURES. A SMALL, LONG-PERIOD
SOUTH-SOUTHWEST SWELL IS POSSIBLE NEXT WEDNESDAY.
HFO WATCHES/WARNINGS/ADVISORIES
HIGH SURF ADVISORY UNTIL 6 AM HST SUNDAY FOR NIIHAU-KAUAI
LEEWARD-WAIANAE COAST-OAHU NORTH SHORE-MAUI WINDWARD WEST-KAUAI
NORTH-MOLOKAI WINDWARD-MOLOKAI NORTH-MOLOKAI WEST-MAUI CENTRAL
VALLEY NORTH-WINDWARD HALEAKALA.
SMALL CRAFT ADVISORY UNTIL 6 PM HST MONDAY FOR ALL HAWAIIAN
WATERS-
DISCUSSION/MARINE...TS
AVIATION...FARRIS
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