056
FXHW60 PHFO 301320
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
320 AM HST THU APR 30 2026
SYNOPSIS
MODERATE TO LOCALLY BREEZY TRADES WILL PREVAIL FOR THE NEXT
SEVERAL DAYS. SHOWERS ARE EXPECTED ACROSS WINDWARD AND MAUKA
AREAS WITH LIMITED SPILLOVER INTO LEEWARD LOCATIONS. A NEARLY
STATIONARY UPPER- LEVEL LOW NORTHEAST OF THE ISLANDS WILL ENHANCE
CLOUDS SHOWERS THROUGH FRIDAY. BY THE WEEKEND, THE DISTURBANCE
ALOFT IS FORECAST TO FINALLY MEANDER FARTHER NORTHEAST AWAY FROM
THE STATE. HOWEVER, PERIODS OF WINDWARD AND MAUKA SHOWERS WILL
CONTINUE.
DISCUSSION
MODERATE TO LOCALLY BREEZY TRADE WINDS CONTINUE TO PREVAIL ACROSS
THE ISLAND CHAIN, STEERED BY TWO AREAS OF HIGH PRESSURE CENTERED
NORTH AND NORTHEAST OF THE ISLANDS THAT ARE SEPARATED BY A FRONT
THAT EXTENDS FROM SOUTHERN ALASKA TO NEAR 30N. AN UPPER-LEVEL LOW
NORTHEAST OF THE STATE IS CAUSING SOME LOCAL INSTABILITY
RESULTING IN DEEPER CLOUDS AND SOME ENHANCED SHOWER ACTIVITY THIS
MORNING PARTICULARLY ACROSS WINDWARD AND MAUKA LOCATIONS WITH
SOME SHOWERS REACHING INTO LEEWARD AREAS.
THE AFOREMENTIONED UPPER-LEVEL LOW WILL REMAIN NEARLY STATIONARY
THROUGH FRIDAY, WHICH WILL CONTINUE THE WET TRADE WIND PATTERN.
SHOWERS WILL FAVOR WINDWARD SLOPES OF ALL ISLANDS, WITH SOME
SHOWERS DRIFTING INTO LEEWARD AREAS. BY THIS WEEKEND, THE UPPER-
LEVEL LOW WILL FINALLY EXIT THE REGION. PERIODS OF SHOWERS WILL
CONTINUE TO FAVOR WINDWARD AND MAUKA AREAS WITH ONLY SLIGHT
VARIATIONS IN DAY- TO-DAY TRADE WINDS EXPECTED OVER THIS
TIME FRAME.
BY EARLY NEXT WEEK, MODEL GUIDANCE SHOWS A SHALLOW COLD FRONT AND
ANOTHER UPPER-LEVEL TROUGH APPROACHING THE ISLANDS FROM THE
NORTHWEST. AT THIS TIME, IT IS UNCERTAIN HOW MUCH MOISTURE CAN BE
EXPECTED FROM THIS SYSTEM.
AVIATION
MODERATE TO LOCALLY BREEZY TRADES PREVAIL THROUGH THE PERIOD AS AN
UPPER-LEVEL LOW POSITIONED JUST NORTHEAST OF THE HAWAIIAN ISLANDS
ENHANCES SHOWER ACTIVITY MAINLY OVER THE WINDWARD MOUNTAIN AREAS.
IN ADDITION, SOME LEEWARD AREAS, ESPECIALLY ALONG WESTERN ISLANDS
SLOPES, COULD SEE SHOWERS DEVELOP EACH DAY AS SEA BREEZES CONVERGE
WITH TRADE WINDS.
CURRENTLY, NO AIRMETS IN EFFECT, HOWEVER, ONCE SHOWER ACTIVITY
INCREASES, AIRMET SIERRA FOR WINDWARD TEMPO MOUNTAIN OBSCURATION
AND AIRMET TANGO FOR LEEWARD TEMPO MODERATE TURBULENCE COULD COME
INTO PLAY.
MARINE
A AREA OF HIGH PRESSURE, CENTERED TO OUR NORTH, WILL SLOWLY MOVE
EAST THROUGH FRIDAY AND GENERATE WIDESPREAD FRESH TO LOCALLY
STRONG TRADE WINDS ACROSS THE LOCAL WATERS. A SMALL CRAFT ADVISORY
IS CURRENTLY IN EFFECT FOR THE TYPICAL WINDY CHANNELS AROUND MAUI
COUNTY AND THE BIG ISLAND. BY THIS WEEKEND, A FRONT PASSING FAR
NORTH OF THE STATE WILL NUDGE THE AFOREMENTIONED HIGH FURTHER
EAST AND ALLOW TRADE WINDS TO DECREASE TO MODERATE TO LOCALLY
FRESH.
THE CURRENT SMALL, NORTHWEST TO NORTH-NORTHWEST (320-330 DEGREE),
SWELL WILL SLOWLY DECLINE INTO FRIDAY AND PRODUCE SMALL SURF
ALONG NORTH FACING BEACHES. A NORTH PACIFIC GALE- FORCE LOW WILL
SEND A MODERATE, LONGER- PERIOD NORTHWEST SWELL TOWARD THE ISLANDS
LATE FRIDAY INTO SATURDAY AND GENERATE ABOVE AVERAGE SURF ALONG
NORTH AND WEST FACING SHORES. AVERAGE H1/10 HEIGHTS FOR NORTH
FACING SHORES IS 6 FEET FOR THE MONTH OF MAY (GODDARD- CALDWELL
DATABASE). HOWEVER, SURF HEIGHTS SHOULD REMAIN BELOW ADVISORY
LEVELS.
SURF ALONG SOUTH-FACING SHORES WILL REMAIN SMALL THROUGH THE REST
OF THIS WORK WEEK, WITH MAINLY BACKGROUND SOUTH TO SOUTHWEST
SWELL EXPECTED. A SMALL, LONG PERIOD, SOUTH-SOUTHWEST PULSE
SHOULD ARRIVE LATE FRIDAY AND GIVE A BUMP UP TO SOUTH FACING
SHORES THROUGH THIS WEEKEND.
SURF ALONG EAST-FACING SHORES WILL REMAIN SLIGHTLY ELEVATED
THROUGH FRIDAY AS TRADES REMAIN FRESH TO LOCALLY STRONG. TRADES WILL
SLOWLY WEAKEN THIS WEEKEND AND ALLOW SURF ALONG EAST-FACING
SHORES TO LOWER.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR KAHOOLAWE.
SMALL CRAFT ADVISORY UNTIL 6 PM HST FRIDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.
DISCUSSION...WALSH
AVIATION...PIERCE
MARINE...THOMAS
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