903
FXHW60 PHFO 311905
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
905 AM HST TUE MAR 31 2026
SYNOPSIS
MODERATE TO LOCALLY BREEZY TRADES WILL PREVAIL THROUGH TODAY,
DECREASING SLIGHTLY BY TOMORROW, BEFORE EASING TO A MORE LIGHT
AND VARIABLE PATTERN BY THIS WEEKEND. SHOWER ACTIVITY WILL BE KEPT
TO A MINIMUM AS A COOLER AND DRIER AIRMASS FILTERS OVER THE
HAWAIIAN ISLANDS. A COLD, UPPER-LEVEL TROUGH MAKES AN APPEARANCE
LATE IN THE WEEK AND MAY SLIGHTLY ENHANCE TRADE WIND SHOWERS, BUT
ANY MEANINGFUL RAINFALL STILL REMAINS UNLIKELY.
SHORT TERM UPDATE
ISSUED AT 905 AM HST TUE MAR 31 2026
THE FORECAST LOOKS ON TRACK THIS MORNING AND NO UPDATES WILL BE
NEEDED.
DISCUSSION
ISSUED AT 316 AM HST TUE MAR 31 2026
AN UPPER-LEVEL TROUGH REMAINS JUST NORTHEAST OF THE HAWAIIAN
ISLANDS, CONTINUING TO SLOWLY SHIFT NORTHEAST, WHILE A BROAD 1032
MB SURFACE HIGH BUILDING IN ITS WAKE FROM THE NORTHWEST. THESE
FEATURES WILL BE THE CATALYST TO DRIVING MODERATE TO LOCALLY
BREEZY TRADES ACROSS STATEWIDE THROUGH MUCH OF TODAY. GUIDANCE
SUGGESTS TODAY WILL BE THE WINDIEST DAY OF THE WEEK, THOUGH MOST
LOCATIONS WILL REMAIN JUST BELOW WIND ADVISORY THRESHOLDS.
HOWEVER, IT CANNOT BE RULED OUT THAT SOME OF THE MORE USUAL WIND-
PRONE LOCATIONS COULD OCCASIONALLY EDGE NEAR THE CRITERIA.
SHOWER ACTIVITY WILL ALSO FOCUS LOW CLOUDS AND SHOWERS ACROSS
WINDWARD AND MAUKA AREAS, BUT RAINFALL WILL BE SPARSE. LATEST
MODEL GUIDANCE CONTINUES TO SHOW PRECIPITABLE WATER VALUES TWO TO
THREE STANDARD DEVIATIONS BELOW AVERAGE. THIS IS LARGELY DUE TO A
DRIER AIRMASS FILTERING IN OVER THE ENTIRE STATE. SOME GUIDANCE
PRESERVE THE SLIGHT UPTICK IN THUNDERSTORM POTENTIAL OF UP TO 15
PERCENT OVER THE SOUTHERN SLOPES OF THE BIG ISLAND. HOWEVER, WITH
MOISTURE LEVELS RUNNING EXCEPTIONALLY LOW, ANY STORMS THAT DO
FORM WOULD LIKELY BE "DRY" THUNDERSTORMS, PRODUCING LIGHTNING WITH
LITTLE TO NO RAINFALL. GIVEN THAT THE ATMOSPHERE MAY STILL BE TOO
DRY, CONFIDENCE OF STORM DEVELOPMENT, TOO, REMAINS LOW.
LOOKING AHEAD, TRADES WILL BEGIN TO EASE BY TOMORROW AS THE
AFOREMENTIONED HIGH PRESSURE WILL BEGIN TO WEAKEN, BECOMING LIGHT
AND VARIABLE BY THIS WEEKEND AND PERSISTING THAT WAY THROUGH THE
REMAINDER OF THE FORECAST PERIOD. RIGHT AROUND THE SAME TIME, A
WEAK UPPER- LEVEL TROUGH IS ANTICIPATED TO PASS WITHIN THE
VICINITY OF THE ISLANDS. MOISTURE WILL REMAIN LIMITED, THOUGH, AND
ANY MEANINGFUL INCREASE IN RAINFALL STILL APPEARS UNLIKELY AT
THIS TIME. THIS SYSTEM WILL BE MONITORED AND REFINED THROUGHOUT
THE NEXT SEVERAL DAYS AS THE PATTERN EVOLVES.
AVIATION
ISSUED AT 316 AM HST TUE MAR 31 2026
MODERATE TO LOCALLY BREEZY TRADE WINDS WILL CONTINUE INTO TONIGHT.
WINDS WILL TAPER OFF TOMORROW MORNING. ISOLATED SHOWERS ARE
POSSIBLE TONIGHT ALONG WINDWARD AND MAUKA AREAS WHICH MAY LOWER
CEILINGS AND VISIBILITIES TO MVFR AT TIMES. OTHERWISE, VFR
CONDITIONS WILL PREVAIL.
AIRMET TANGO IS IN EFFECT FOR MOD TURB BLW 080 DOWNWIND OF
TERRAIN.
MARINE
ISSUED AT 905 AM HST TUE MAR 31 2026
THE PRESSURE GRADIENT BETWEEN A HIGH LOCATED ABOUT 800 NM NORTH
OF OAHU AND A TROUGH JUST EAST OF THE FAR OFFSHORE WATERS WILL
SLIGHTLY WEAKEN THROUGH MID WEEK. THE RESULT WILL BE TRADES
FALLING BACK TO MORE MODERATE MAGNITUDES WEDNESDAY MORNING AND
REMAINING AT THESE SPEEDS THROUGH THE REMAINDER OF THE WEEK. THE
SMALL CRAFT ADVISORY FOR MODERATE TO LOCALLY FRESH TRADES REMAINS
IN EFFECT UNTIL 6 PM HST TODAY. A TROUGH FORMING BETWEEN THE
EXITING HIGH TO THE NORTHEAST AND THE NEXT HIGH MOVING IN FROM THE
WEST CENTRAL PACIFIC WILL MAINTAIN GENTLE TO MODERATE TRADES THIS
WEEKEND.
NORTH AND EAST-FACING SHORE SURF WILL REMAIN UNDER ADVISORY HEIGHTS
AS NEAR 9 FOOT, SHORT PERIOD NNE (020-030 DEGREE) VEERING SWELL
HOLDS THROUGH THE DAY AND THEN SLOWLY FALLS THROUGH THE WEEK.
THERE IS STILL ENOUGH OF A NORTHERLY COMPONENT TO THE SWELL TO
CONTINUE TO MESSAGE THE POTENTIAL FOR MINOR SURGES WITHIN NORTH-
FACING HARBORS TODAY. SHORES BETTER EXPOSED TO THIS NNE SWELL WILL
EXPERIENCE DECENT WIND WAVE CHOP GENERATED BY SOLID MODERATE
TRADES.
SOUTH SHORE SURF WILL REMAIN SMALL THIS WEEK WITH ONLY BACKGROUND
SWELL PROVIDING MINOR PULSES THE NEXT SEVERAL DAYS. ANY SOURCE,
SUCH AS SOUTHERN HEMISPHERIC GALE LOWS, WILL BE TOO FAR SOUTH AND
MOVING AT TOO QUICK OF AN EASTERLY PACE TO PUSH ANY SIGNIFICANT
SWELL UP INTO OUR LOCAL SOUTHERN WATERS GOING THROUGH THE FIRST
WEEK OF APRIL.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST THIS EVENING FOR ALENUIHAHA
CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS-
BIG ISLAND WINDWARD WATERS-KAIWI CHANNEL-KAUAI CHANNEL-KAUAI
LEEWARD WATERS-KAUAI NORTHWEST WATERS-KAUAI WINDWARD WATERS-
MAALAEA BAY-MAUI COUNTY LEEWARD WATERS-MAUI COUNTY WINDWARD
WATERS-OAHU LEEWARD WATERS-OAHU WINDWARD WATERS-PAILOLO CHANNEL.
SHORT TERM UPDATE...FOSTER
DISCUSSION...PIERCE
AVIATION...WALSH
MARINE...BLOOD
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