284
FXHW60 PHFO 100652
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
852 PM HST SUN MAR 9 2025
SYNOPSIS
A WET AND WINDY TRADE WIND PATTERN WILL PERSIST THROUGH MONDAY AS
A DISSIPATING COLD FRONT DRIFTS SOUTHWARD THROUGH THE ISLANDS.
WHILE MOST SHOWERS WILL FAVOR WINDWARD AND MAUKA LOCATIONS, SOME
WILL PERIODICALLY REACH LEEWARD AREAS OF THE SMALLER ISLANDS.
DRIER CONDITIONS WILL MOVE IN BY TUESDAY AS THE FRONT SHIFTS AWAY.
BREEZY TO WINDY TRADES WILL CONTINUE THROUGH MIDWEEK BEFORE
GRADUALLY EASING BY FRIDAY AS THE RIDGE WEAKENS TO THE NORTH.
DISCUSSION
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT, SHOWING A STRONG LOW-
TO MID-LEVEL RIDGE ANCHORED NORTH OF THE ISLANDS HOLDING FIRM
THROUGH THE FIRST HALF OF THE WEEK. THIS SETUP WILL MAINTAIN
BREEZY TO WINDY TRADE WINDS. A WEAK UPPER TROUGH LINGERING NEARBY
WILL KEEP THE INVERSION WEAK AND SLIGHTLY ELEVATED, ALLOWING FOR
OCCASIONAL INCREASES IN WINDWARD AND LEEWARD SHOWERS AS SHALLOW
BANDS OF MOISTURE MOVE THROUGH.
THIS EVENING, A DISSIPATING COLD FRONT, SHOWN ON SATELLITE AS A
SHALLOW BAND OF CLOUDS AND MOISTURE, IS SETTLING SOUTHWARD INTO
THE SMALLER ISLANDS. THIS FEATURE IS SUPPORTING A WET TRADE WIND
PATTERN, WITH FREQUENT WINDWARD AND MAUKA SHOWERS AND OCCASIONAL
SPILLOVER INTO LEEWARD AREAS. THE EVENING RAINFALL SUMMARY SHOWED
PEAK TOTALS IN THE PAST 6 HOURS (THROUGH 8 PM HST) NEAR 2 INCHES
ON KAUAI AND UP TO A QUARTER OF AN INCH ON OAHU AND MAUI. THE BAND
WILL CONTINUE DRIFTING SOUTHWARD THROUGH THE ISLANDS OVERNIGHT
INTO MONDAY BEFORE SHIFTING AWAY BY TUESDAY, ALLOWING DRIER AIR TO
FILL IN.
TRADE WINDS WILL REMAIN IN THE BREEZY TO WINDY RANGE THROUGH
MONDAY, WITH A GRADUAL STRENGTHENING TREND EXPECTED BY TUESDAY AS
HIGH PRESSURE BUILDS NORTH OF THE STATE. THIS WILL LIKELY BRING
STRONGER TRADES, POTENTIALLY REACHING WIND ADVISORY LEVELS ACROSS
THE TYPICALLY WINDIER AREAS OF MAUI COUNTY AND THE BIG ISLAND.
DESPITE THE DRIER AIR EXPECTED, SPOTTY SHOWERS WILL REMAIN IN THE
FORECAST, PARTICULARLY FOR WINDWARD AND MAUKA AREAS OVERNIGHT
THROUGH THE MORNINGS.
BY LATE WEEK INTO NEXT WEEKEND, THE RIDGE COULD WEAKEN, ALLOWING
TRADE WINDS TO GRADUALLY EASE. EASTERLY WINDS MAY ALSO VEER
SLIGHTLY MORE EAST-SOUTHEAST AS A TROUGH ALOFT DEVELOPS WELL
NORTHWEST OF THE ISLANDS. THIS SHIFT COULD LEAD TO A FURTHER
WEAKENING TREND IN THE TRADES HEADING INTO THE WEEKEND.
AVIATION
A LONG BAND OF UNSTABLE CLOUDS, ASSOCIATED WITH A DISSIPATING
COLD FRONT, DRIFTS INTO THE HAWAIIAN ISLANDS FROM THE NORTH
THROUGH MONDAY. EXPECT WET AND BREEZY TRADE WIND WEATHER BRINGING
PERIODS OF MVFR CONDITIONS IN SHOWERS TO ALL ISLANDS OVER THE
NEXT 24 TO 36 HOURS.
AIRMET SIERRA FOR MOUNTAIN OBSCURATION IS CURRENTLY IN EFFECT FOR
NORTH AND EAST FACING SLOPES OF KAUAI AND OAHU. THESE CONDITIONS
WILL EXPAND EASTWARD TO MOLOKAI, MAUI AND THE BIG ISLAND LATER
TONIGHT AS THE FRONTAL BAND CONTINUES TO DRIFT SOUTHWARD.
AIRMET TANGO REMAINS IN EFFECT FOR MODERATE LOW LEVEL TURBULENCE
OVER AND DOWNWIND OF ISLAND TERRAIN. THIS AIRMET IS EXPECTED TO
CONTINUE OVER THE NEXT SEVERAL DAYS. TANGO WAS ALSO ISSUED FOR
MODERATE TURBULENCE ALOFT BETWEEN FL270 AND FL360 DUE TO A
LINGERING SUBTROPICAL JET STREAM.
MARINE
STRONG SURFACE HIGH PRESSURE CENTERED FAR NORTH OF HAWAII WILL
MAINTAIN A VERY TIGHT PRESSURE GRADIENT BETWEEN ITSELF AND LOWER
EQUATORIAL PRESSURE, RESULTING IN AN EXTENDED PERIOD OF FRESH TO
STRONG TRADE WINDS. A FRONT WILL DISSIPATE OVER THE STATE TONIGHT
AND BRING GUSTY SCATTERED TO NUMEROUS SHOWERS TO NEARLY ALL LOCAL
WATERS. TUESDAY THROUGH EARLY THURSDAY, EXPECT STRONG- TO NEAR
GALE-FORCE TRADE WINDS, WITH THE STRONGEST OVER THE TYPICALLY
WINDIER WATERS AND CHANNELS SURROUNDING MAUI COUNTY AND BIG
ISLAND. THE SMALL CRAFT ADVISORY FOR ALL HAWAIIAN WATERS WILL
REMAIN IN EFFECT FOR THE NEXT SEVERAL DAYS FOR THE STRONG WINDS
AND RESULTING ROUGH SEAS.
THE CURRENT MODERATE, MEDIUM PERIOD, NORTH-NORTHWEST SWELL (340
DEGREE) WILL PROGRESSIVELY DECLINE THROUGH MID-WEEK. A SIMILAR
SIZED, LONG-PERIOD NORTHWEST (330 DEGREE) SWELL WILL ARRIVE ON
WEDNESDAY, WITH A REINFORCING LONG-PERIOD NORTHWEST SWELL (310
DEGREE) ON ITS HEELS TO CLOSE OUT THE WEEK.
ROUGH SURF WILL CONTINUE ALONG EAST FACING SHORES THROUGH THE
WEEK IN RESPONSE TO THE PERSISTENT STRONG TRADE WINDS OVER AND
UPSTREAM OF THE ISLANDS. SURF WILL NEAR THE ADVISORY LEVEL TUESDAY
THROUGH MIDWEEK AS TRADES STRENGTHEN.
SURF ALONG SOUTH-FACING SHORES WILL REMAIN SMALL, ASIDE FROM THE
POSSIBILITY OF SOME WRAP FROM THE EASTERLY WIND WAVES MAKING IT
INTO THE MORE EASTERN-FACING SOUTHERN EXPOSURES.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR ALL HAWAIIAN
WATERS-
DISCUSSION...GIBBS
AVIATION...BOHLIN
MARINE...THOMAS
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