118
FXHW60 PHFO 150659
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
859 PM HST MON APR 14 2025
SYNOPSIS
A TYPICAL MODERATE TO LOCALLY BREEZY TRADE WIND PATTERN WILL
PREVAIL THROUGH TUESDAY, WITH SHOWERS FAVORING WINDWARD AND MAUKA
AREAS. THE TRADES WILL EASE TUESDAY NIGHT, WITH A CONVECTIVE
SHOWER PATTERN DEVELOPING WEDNESDAY AND CONTINUING THROUGH FRIDAY.
A DISTURBANCE ALOFT MOVING OVER THE ISLANDS COULD BRING SOME
HEAVIER SHOWERS AND EVEN A FEW THUNDERSTORMS AS IT SLOWLY SHIFTS
EASTWARD ACROSS THE STATE. A RETURN TO A MORE TYPICAL TRADE WIND
REGIME ALONG WITH A GRADUAL INCREASE IN TRADE WIND SPEEDS WILL BE
POSSIBLE OVER THE WEEKEND INTO EARLY NEXT WEEK.
DISCUSSION
CURRENTLY AT THE SURFACE, A COLD FRONT IS LOCATED AROUND 1100
MILES WEST-NORTHWEST OF KAUAI, WHILE A 1029 MB HIGH IS CENTERED
AROUND 1350 MILES NORTHEAST OF HONOLULU. THE RESULTING GRADIENT IS
PRODUCING MODERATE TRADE WINDS OVER THE WESTERN ISLANDS AND BREEZY
TRADES OVER THE EASTERN END OF THE STATE. INFRARED SATELLITE
IMAGERY SHOWS PARTLY TO MOSTLY CLOUDY CONDITIONS ACROSS THE
STATE. RADAR IMAGERY SHOWS SCATTERED SHOWERS MOVING INTO WINDWARD
AREAS, WITH A FEW SHOWERS REACHING LEEWARD COMMUNITIES AT TIMES.
MAIN SHORT TERM FOCUS REVOLVES AROUND TRADE WIND TRENDS AND RAIN
CHANCES.
THE RIDGE TO THE NORTH OF THE ISLANDS WILL GRADUALLY WEAKEN AND
ERODE DURING THE NEXT COUPLE DAYS AS A COLD FRONT APPROACHES FROM
THE NORTHWEST. THE TRADES WILL HANG ON AT MODERATE TO LOCALLY
BREEZY LEVELS THROUGH TUESDAY, WITH A GRADUAL EASING OCCURRING
DURING THIS TIME. THE TRADES WILL BECOME DISRUPTED BY ON
WEDNESDAY, WITH SEA BREEZES BECOMING COMMON OVER THE WESTERN
ISLANDS, WHILE THE TRADES SHIFT EAST-SOUTHEASTERLY AT LIGHT TO
MODERATE SPEEDS OVER THE EASTERN END OF THE STATE. THE FRONT WILL
STALL OUT NORTHWEST OF THE STATE THURSDAY AND FRIDAY, WITH BROAD
TROUGHING IN PLACE ACROSS THE ISLAND CHAIN. LAND AND SEA BREEZES
WILL REMAIN COMMON DURING THIS TIME, WITH BACKGROUND LIGHT
EAST-SOUTHEAST WINDS CONFINED TO AREAS AROUND THE BIG ISLAND.
THE TROUGH APPEARS TO DAMPEN OUT OVER THE WEEKEND, ALLOWING A
GRADUAL RETURN AND STRENGTHENING OF THE TRADES WHICH WILL CONTINUE
INTO EARLY NEXT WEEK.
AS FOR THE REMAINING WEATHER DETAILS, A FAIRLY TYPICAL TRADE WIND
SHOWER PATTERN WILL PREVAIL TONIGHT THROUGH TUESDAY NIGHT, WITH
SHOWERS FAVORING WINDWARD SLOPES AND COASTS. A SLIGHT EASING OF
THE TRADES COULD ALLOW FOR AN INCREASE IN LEEWARD SHOWERS TUESDAY
AFTERNOON HOWEVER, WITH MOST OF THESE SHOWERS FIZZLING OUT
QUICKLY IN THE EVENING. A TRANSITION TO A CONVECTIVE PATTERN IS
EXPECTED WEDNESDAY THROUGH FRIDAY, WITH SHOWERS FAVORING THE
ISLAND INTERIORS DURING THE AFTERNOON AND EVENING HOURS, AND AREAS
NEAR THE COAST AT NIGHT. AN UPPER LEVEL TROUGH WILL MOVE SLOWLY
EASTWARD ACROSS THE STATE WEDNESDAY NIGHT THROUGH FRIDAY, WITH 500
MB TEMPERATURES LOWERING TO AROUND -12 TO -13C AND PRECIPITABLE
WATER VALUES INCREASING TO AROUND 1.5 INCHES. THIS WILL LIKELY
BRING SOME HEAVIER SHOWERS TO THE AREA, PARTICULARLY DURING THE
AFTERNOON AND EVENING HOURS. ISOLATED THUNDERSTORMS WILL ALSO BE
POSSIBLE AS THE COLD POOL ALOFT MOVES EASTWARD ACROSS THE STATE. A
MORE TYPICAL TRADE WIND PATTERN MAY SLOWLY RETURN OVER THE WEEKEND
INTO EARLY NEXT WEEK.
AVIATION
MODERATE TO BREEZY TRADE WINDS WILL GRADUALLY EASE TONIGHT AND
TOMORROW. AIRMET TANGO FOR TURBULENCE BELOW 8,000 FEET OVER AND
DOWNWIND OF TERRAIN REMAINS IN EFFECT, BUT WILL LIKELY BE DROPPED
OVERNIGHT AS LOW LEVEL WINDS SUBSIDE.
CLOUDS AND SHOWERS WILL GENERALLY FAVOR WINDWARD COASTS THROUGH
TONIGHT AND INTO TOMORROW. HOWEVER, CLOUDS AND SHOWERS WILL BUILD
OVER LEEWARD SLOPES OF THE BIG ISLAND TOMORROW AFTERNOON AND AS
THE STEERING FLOW SHIFTS TO BECOME MORE SOUTHEASTERLY, CONVERGENT
BOUNDARIES MAY BRING CLOUDS AND SHOWERS TO LEEWARD AREAS OF SOME
OF THE SMALLER ISLANDS AS WELL. MVFR CONDITIONS WILL BE POSSIBLE
IN ANY SHOWERS, BUT OVERALL, VFR CONDITIONS WILL PREVAIL.
MARINE
FRESH TO STRONG EASTERLY TRADE WINDS WILL GRADUALLY EASE AND
SHIFT OUT OF THE EAST-SOUTHEAST TUESDAY THROUGH THE SECOND HALF OF
THE WEEK AS A FRONT APPROACHES AND STALLS NORTHWEST OF THE STATE.
OVER THE WESTERN END OF THE ISLANDS, THE WEAKENING WINDS WILL
ALLOW A LAND AND SEA BREEZE PATTERN TO DEVELOP. FOR THE EASTERN
END OF THE STATE, MODERATE TO FRESH EAST TO SOUTHEAST BREEZES,
WITH LOCALIZED STRONG POCKETS, WILL LIKELY PERSIST, PARTICULARLY
AROUND THE BIG ISLAND. AS A RESULT, THE SMALL CRAFT ADVISORY MAY
NEED TO BE EXTENDED FOR WATERS SURROUNDING THE BIG ISLAND. A
RETURN TO MODERATE TO FRESH EASTERLY TRADES IS POSSIBLE BY THE
WEEKEND AS THE RIDGE REESTABLISHES TO THE NORTH.
SURF ALONG EXPOSED NORTH AND WEST FACING SHORES WILL STEADILY
LOWER TUESDAY THROUGH MIDWEEK AS A MEDIUM-PERIOD NORTHWEST SWELL
EASES. OBSERVATIONS AT OFFSHORE BUOYS TO THE NORTHWEST REFLECT
THIS DOWNWARD TREND THIS EVENING, WITH PEAK ENERGY SHIFTING
INTO THE 12-14 SECOND BANDS. A FRESH PULSE OUT OF THE NORTH-
NORTHWEST IS EXPECTED TO ARRIVE THURSDAY, POTENTIALLY PEAKING
NEAR ADVISORY LEVELS FOR EXPOSED NORTH AND WEST FACING SHORES
THURSDAY NIGHT INTO FRIDAY. A DOWNWARD TREND IS THEN EXPECTED
OVER THE WEEKEND.
SURF ALONG EAST FACING SHORES WILL TREND DOWN THROUGH THE WEEK AS
THE TRADES EASE AND SHIFT OUT OF THE EAST-SOUTHEAST.
SURF ALONG SOUTH FACING SHORES WILL REMAIN SMALL THROUGH THE WEEK,
WITH MAINLY OVERLAPPING BACKGROUND SWELLS MOVING THROUGH.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 AM HST TUESDAY FOR KAIWI CHANNEL-
MAUI COUNTY WINDWARD WATERS-MAUI COUNTY LEEWARD WATERS-MAALAEA
BAY-PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND WINDWARD
WATERS-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS.
DISCUSSION...JELSEMA
AVIATION...FARRIS
MARINE...GIBBS
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