528
FXHW60 PHFO 160632
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
832 PM HST TUE APR 15 2025
SYNOPSIS
THE TRADE WINDS WILL CONTINUE TO EASE TONIGHT, WITH A DAYTIME SEA
BREEZE AND OVERNIGHT LAND BREEZE PATTERN SETTING UP WEDNESDAY
THROUGH FRIDAY. A DISTURBANCE ALOFT MOVING OVER THE ISLANDS COULD
BRING SOME HEAVIER SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY.
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
NORTHWEST OF KAUAI, WHILE A 1031 MB HIGH IS CENTERED AROUND 2250
MILES NORTH-NORTHEAST OF HONOLULU. THE TRADES HAVE EASED THROUGH
THE DAY, AND ARE NOW BLOWING AT LIGHT TO MODERATE SPEEDS. INFRARED
SATELLITE IMAGERY SHOWS PARTLY TO MOSTLY CLOUDY CONDITIONS IN
PLACE, WHILE RADAR IMAGERY SHOWS SHOWERS SCATTERED ACROSS THE
STATE. MAIN SHORT TERM FOCUS REVOLVES AROUND TRADE WIND TRENDS
AND RAIN CHANCES.
A RIDGE TO THE NORTH OF THE ISLANDS WILL GRADUALLY WEAKEN AND
ERODE DURING THE DAY OR SO, AS A COLD FRONT APPROACHES FROM THE
NORTHWEST. THE TRADES WILL EASE TONIGHT, THEN BECOME DISRUPTED
WEDNESDAY, WITH SEA BREEZES 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 AREA THURSDAY, WITH BROAD TROUGHING DEVELOPING
ACROSS THE ISLAND CHAIN. LAND AND SEA BREEZES WILL REMAIN COMMON
DURING THIS TIME, WITH BACKGROUND LIGHT TO MODERATE EAST-
SOUTHEAST WINDS CONFINED TO AREAS AROUND THE BIG ISLAND. THE
TROUGH APPEARS TO DAMPEN FRIDAY THROUGH THE WEEKEND, ALLOWING A
GRADUAL RETURN AND STRENGTHENING OF THE TRADES WHICH WILL
CONTINUE INTO EARLY NEXT WEEK.
AS FOR THE REMAINING WEATHER DETAILS, THE LINGERING DAYTIME
HEATING SHOWERS SHOULD CONTINUE TO DIMINISH OVER THE NEXT COUPLE
HOURS, WHILE ISOLATED TO SCATTERED SHOWERS CONTINUE TO ROLL INTO
WINDWARD AREAS THROUGH THE NIGHT. A TRANSITION OVER TO A
CONVECTIVE PATTERN IS EXPECTED WEDNESDAY, WITH SHOWERS FAVORING
THE ISLAND INTERIORS DURING THE AFTERNOON AND EVENING HOURS, AND
AREAS NEAR THE COAST AT NIGHT. THIS PATTERN WILL LINGER INTO
FRIDAY WHEN THE TRADES WILL BEGIN TO RETURN. MEANWHILE, AN UPPER
LEVEL TROUGH WILL MOVE SLOWLY EASTWARD ACROSS THE STATE WEDNESDAY
NIGHT INTO FRIDAY, WITH 500 MB TEMPERATURES OF -12 TO -13C AND
PRECIPITABLE WATER VALUES INCREASING TO AROUND 1.5 INCHES. THIS
WILL LIKELY RESULT IN SOME HEAVIER SHOWERS, 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 LATE
FRIDAY THROUGH EARLY NEXT WEEK.
AVIATION
MODERATE EASTERLY TRADES WILL GRADUALLY VEER AND EASE TONIGHT
THROUGH WEDNESDAY CONTINUING TO BRING THE POTENTIAL FOR SHRA AND
LOW CIGS TO WINDWARD AND MAUKA LOCATIONS. HOWEVER, WINDS MAY BEGIN
TO BE LIGHT ENOUGH TO SEE SOME SEA BREEZE DEVELOPMENT AS CONVERGENT
BOUNDARIES MAY BE ANOTHER SOURCE OF CLOUDS AND SHOWERS TO LEEWARD
AREAS OF SOME OF THE SMALLER ISLANDS. MVFR CONDITIONS WILL BE
POSSIBLE IN ANY SHOWERS, BUT OVERALL, VFR CONDITIONS WILL PREVAIL.
WHILE THE ONGOING ERUPTION OF KILAUEA IS CURRENTLY PAUSED, THERE
IS DEGASSING OCCURRING. THIS COULD CAUSE SOME HAZY CONDS ACROSS
THE ISLANDS. IT IS NOT ENOUGH TO IMPACT VSBYS AT THIS TIME AND NOT
CURRENTLY IN ANY TAFS BUT WAS WORTH A MENTION.
NO AIRMETS IN EFFECT.
MARINE
MODERATE TO FRESH TRADE WINDS WILL CONTINUE TO EASE AND SHIFT OUT
OF THE EAST-SOUTHEAST OVERNIGHT THROUGH MIDWEEK 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 NEAR THE COASTS, WHICH WILL PERSIST
INTO FRIDAY. FOR THE EASTERN END OF THE STATE, LIGHT TO MODERATE
EAST TO SOUTHEAST BREEZES, WITH LOCALIZED FRESH POCKETS, WILL
LIKELY PERSIST, PARTICULARLY AROUND THE BIG ISLAND. A RETURN TO
FRESH TO STRONG EASTERLY TRADES IS POSSIBLE BY THE WEEKEND AS THE
RIDGE REESTABLISHES TO THE NORTH.
AS TRADES DIMINISH, CHANCES FOR HEAVY SHOWERS AND THUNDERSTORMS
WILL INCREASE. THE MAIN THREAT WILL DEVELOP AROUND KAUAI AND OAHU
LATE WEDNESDAY NIGHT, SLOWLY SPREAD TO THE ENTIRE ISLAND CHAIN
THURSDAY, THEN DIMINISH FROM WEST TO EAST ON FRIDAY.
SURF ALONG EXPOSED NORTH AND WEST FACING SHORES WILL CONTINUE TO
LOWER THROUGH WEDNESDAY AS A NORTHWEST SWELL FADES. A MEDIUM-
PERIOD NORTH-NORTHWEST SWELL WILL BUILD THURSDAY, LIKELY DRIVING
SURF HEIGHTS NEAR ADVISORY LEVELS DURING THE PEAK THURSDAY NIGHT
AND EARLY FRIDAY. THIS SWELL WILL STEADILY DECLINE AND SHIFT OUT
OF THE NORTH LATER FRIDAY AND THE WEEKEND.
SURF ALONG EAST FACING SHORES WILL TREND DOWN INTO WEDNESDAY AS
TRADES EASE. EAST SHORE SURF WILL REMAIN BELOW APRIL AVERAGE
THROUGH AT LEAST SATURDAY AND WILL LIKELY RISE TO AROUND AVERAGE
ON SUNDAY.
SURF ALONG SOUTH FACING SHORES WILL REMAIN SMALL THROUGH MOST OF
THE WEEK, WITH MAINLY OVERLAPPING BACKGROUND SOUTH SWELLS MOVING
THROUGH. A LARGER PULSE OF SOUTH-SOUTHWEST SWELL MAY ARRIVE
TUESDAY.
HFO WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...JELSEMA
AVIATION...SHIGESATO
MARINE...GIBBS
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