024
FXHW60 PHFO 151932
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
932 AM HST MON JUN 15 2026
SYNOPSIS
SURFACE HIGH PRESSURE CENTERED NORTHEAST OF THE STATE WILL
CONTINUE TO DRIVE MODERATE TRADES ACROSS THE ISLANDS TODAY. THERE
WILL BE A DECREASE IN CLOUD AND SHOWER COVERAGE AS THE DAY
PROGRESSES AS A DRIER AND MORE STABLE AIRMASS MOVES IN. EXPECT
LITTLE CHANGE IN THE WEATHER PATTERN ON TUESDAY, THOUGH TRADES
WILL BE SLIGHTLY WEAKER. WEDNESDAY INTO THURSDAY, LIGHT EASTERLY
FLOW WILL LEAD TO A SEA BREEZE AND LAND BREEZE REGIMEN. THUS, MOST
CLOUD COVER AND SHOWER ACTIVITY WILL BE LIMITED TO INTERIOR AND
MOUNTAINOUS TERRAIN DURING THE AFTERNOONS. IN ADDITION, DEEPER
MOISTURE MOVING IN FROM THE SOUTHEAST WEDNESDAY THROUGH FRIDAY
SHOULD BRING INCREASED PRECIPITATION CHANCES TO THE BIG ISLAND,
AND PERHAPS MAUI.
SHORT TERM UPDATE
THE FORECAST REMAINS ON TRACK THIS MORNING, WITH ISOLATED WINDWARD
SHOWERS EMBEDDED WITHIN THE TRADE WIND FLOW. NO MAJOR UPDATES TO
THE FORECAST HAVE BEEN MADE AT THIS TIME.
PREV DISCUSSION
ISSUED AT 346 AM HST MON JUN 15 2026
IR SATELLITE LOOP AND RADAR IMAGERY FROM EARLY THIS MORNING
CONTINUED TO SHOW A BAND OF LOW CLOUDS AND SCATTERED SHOWERS
PUSHING WESTWARD OVER THE ISLAND CHAIN. RAINFALL AMOUNTS FROM
MIDNIGHT HAVE NOT BEEN ALL THAT IMPRESSIVE, WITH WINDWARD SITES ON
ALL ISLANDS PICKING UP LESS THAN A QUARTER INCH OF RAINFALL
ACCUMULATION. ON OAHU, THE CLOUD LAYER WAS DEEP ENOUGH TO SPILL
OVER THE KOOLAU RANGE AND ONTO LEEWARD LOCATIONS, THOUGH ONLY A
FEW HUNDREDTHS OF AN INCH WERE REPORTED.
A 1025 MB SURFACE HIGH, CENTERED ROUGHLY 1,600 MILES NORTHEAST OF
THE STATE, WILL REMAIN PARKED IN PLACE THROUGH LATE TODAY AND ALLOW
MODERATE TO LOCALLY BREEZY TRADES TO LINGER. CLOUD COVER AND
SHOWERS SHOULD GRADUALLY DWINDLE THROUGH THE DAY AS THESE TRADES
HELP USHER IN A DRIER AIRMASS. AS STABILITY ALOFT INCREASES, A MODEL
TIME-HEIGHT CROSS-SECTION SHOWS THE BOUNDARY LAYER TEMPERATURE
INVERSION HEIGHT, OR CAPPING INVERSION, LOWERING TO 5000 TO 6000
FEET. A FEW ISOLATED SHOWERS MAY AFFECT WINDWARD LOCATIONS LATE
TODAY THROUGH TONIGHT NIGHT, BUT NOTHING OF SIGNIFICANCE.
TUESDAY'S WEATHER TO BE VERY SIMILAR TO TODAY'S, THOUGH THE
AFOREMENTIONED SURFACE HIGH LIFTS FURTHER NORTH, AWAY FROM HAWAII,
LEADING TO SLIGHTLY WEAKER TRADES.
ON WEDNESDAY, AN UPPER LEVEL TROUGH BEGINS TO DIG SOUTHWARD OVER
THE CENTRAL NORTH PACIFIC, ALONG WITH THE DEVELOPMENT OF A
SURFACE FRONTAL BOUNDARY NORTHWEST OF THE STATE. THIS SHOULD HELP
WEAKEN LOCAL PRESSURE GRADIENTS FURTHER AND BRING LIGHT AND
VARIABLE BACKGROUND FLOW. FOR THE SMALLER ISLANDS, DIURNAL
HEATING, COMBINED WITH WEAK SURFACE FLOW, WILL LEAD TO A DIURNAL
SEA BREEZES AND NOCTURNAL LAND BREEZES. CLOUDS AND SHOWERS SHOULD
MAINLY BE LIMITED TO OVER THE ISLAND INTERIORS AND MOUNTAINOUS
TERRAIN. MEANWHILE, BY LATE WEDNESDAY, BOTH THE GFS AND ECMWF HAVE
BEEN CONSISTENT WITH ADVECTING A POCKET OF DEEPER MOISTURE
ASSOCIATED WITH A WEAK SURFACE TROUGH UP FROM THE SOUTHEAST
TOWARDS THE BIG ISLAND. THIS FEATURE COULD ACT TO INCREASE SHOWER
COVERAGE, ESPECIALLY ALONG EASTERN PORTIONS OF THE BIG ISLAND.
THE EXACT TIMING AND AND IMPACTS, IF ANY, FROM THIS POTENTIAL
INCREASE IN RAINFALL WILL BE REFINED IN THE COMING DAYS. LONG
RANGE MODELS CONTINUE TO PUSH THIS BAND OF MOISTURE UP THROUGH
MAUI COUNTY AND TO A LESSER EXTENT OAHU ON THURSDAY INTO FRIDAY,
BEFORE LIFTING IT NORTHWARD. LIGHT SOUTHEAST FLOW, COMBINED WITH
THIS BATCH OF MOISTURE, COULD LEAD TO AN INCREASE IN SHOWER
ACTIVITY OVER THE ISLANDS INTERIORS DURING THE AFTERNOONS. TYPICAL
JUNE TRADE WIND WEATHER SHOULD BY THIS WEEKEND.
AVIATION
ISSUED AT 346 AM HST MON JUN 15 2026
LIGHT TO MODERATE TRADES PERSIST THROUGH THE MORNING HOURS,
OCCASIONALLY LIGHT ENOUGH FOR SEA BREEZES TO DEVELOP. TRADES
INCREASE SLIGHTLY THROUGHOUT THE MORNING, WITH PERIODS OF GUSTY
WINDS AT TIMES. LOW-LEVEL MOISTURE EMBEDDED WITHIN THESE TRADES
MAY LEAD TO LIGHT SHOWER ACTIVITY RESULTING IN PERIODIC MVFR
CONDITIONS, NAMELY ACROSS WINDWARD AND MAUKA AREAS. OTHERWISE, VFR
CONDITIONS PREVAIL.
AIRMET TANGO REMAINS IN EFFECT FOR MODERATE TURBULENCE OVER THE
BIG ISLAND BETWEEN FL300 TO FL400.
MARINE
ISSUED AT 346 AM HST MON JUN 15 2026
MODERATE TRADE WINDS TODAY WILL BECOME LIGHT TO MODERATE WITH
LOCAL LAND AND SEA BREEZES THROUGH THE WEEK AS HIGH PRESSURE
WEAKENS.
THE LARGE LONG PERIOD SOUTH SOUTHWEST SWELL WILL HOLD AROUND WARNING
LEVELS TODAY AND A HIGH SURF WARNING IS IN PLACE THROUGH TONIGHT.
BUOY 51002 READINGS THIS MORNING ARE HOVERING AROUND 4 TO 6 FEET
AT 17 TO 19 SECONDS. AS THE PERIOD HAS DROPPED SLIGHTLY FROM
YESTERDAY, THE CONSISTENCY OF THE SETS COULD INCREASE, WHICH
COULD LEAD TO MORE WATER ACCUMULATING NEAR THE SHORELINES. THE
SURF WILL THEN GRADUALLY LOWER TUESDAY AND WEDNESDAY, THEN
ANOTHER PULSE ARRIVES WEDNESDAY NIGHT INTO THURSDAY WHICH COULD
PUSH SURF BACK UP TO ADVISORY LEVELS. THE LARGE SOUTH- SOUTHWEST
SWELL COMBINED WITH KING TIDES WILL CONTINUE TO CREATE THE
POTENTIAL FOR SIGNIFICANT WAVE RUN UP ALONG SOUTH AND WEST FACING
SHORES THROUGH THE AFTERNOON.
VERY LITTLE SWELL ENERGY IS ARRIVING ALONG NORTH FACING SHORES,
KEEPING SURF TINY TO FLAT. A SMALL BUMP IN SURF IS POSSIBLE FOR NORTH-
FACING SHORES BY LATE TUESDAY INTO WEDNESDAY WITH THE ARRIVAL OF
A SMALL NORTHWEST SWELL AND A SMALLER NORTH SWELL. GENTLE TO
MODERATE EAST-NORTHEASTERLY WINDS EXPECTED THROUGH NEXT WEEK WILL
KEEP SURF ALONG EAST FACING SHORES BELOW SEASONAL AVERAGE.
A COASTAL FLOOD STATEMENT REMAINS IN EFFECT FOR MINOR COASTAL
FLOODING OF VULNERABLE LOW-LYING COASTAL ROADWAYS, DOCKS, BOAT
RAMPS AND OTHER COASTAL INFRASTRUCTURE. KING TIDES COMBINED WITH
WATER LEVELS THAT ARE RUNNING HIGHER THAN PREDICTED WILL LEAD TO
MINOR FLOODING POTENTIAL AROUND THE DAILY PEAK TIDE, WHICH WILL BE
DURING THE LATE AFTERNOON AND EARLY EVENING HOURS, THROUGH AT
LEAST TUESDAY. WHILE MINOR COASTAL FLOODING IS EXPECTED ALONG ALL
SHORELINES, THE COMBINATION OF THE SOUTH-SOUTHWEST SWELL, KING
TIDES AND THE DAILY HIGH TIDE WILL MAKE LOW-LYING COASTAL AREAS
ALONG SOUTH AND WEST SHORES SUSCEPTIBLE TO MORE WIDESPREAD COASTAL
FLOODING THROUGH THE FIRST HALF OF NEXT WEEK.
A MARINE WEATHER STATEMENT ALSO REMAINS IN EFFECT DUE TO THE LARGE
LONG-PERIOD SOUTH-SOUTHWEST SWELL PRODUCING HARBOR SURGES AND
BREAKING WAVES NEAR HARBOR ENTRANCES ALONG SOUTH AND WEST FACING
HARBORS.
HFO WATCHES/WARNINGS/ADVISORIES
HIGH SURF WARNING UNTIL 6 AM HST TUESDAY FOR BIG ISLAND SOUTH-
BIG ISLAND SOUTHEAST-EAST HONOLULU-EWA PLAIN-HONOLULU METRO-
KAHOOLAWE-KAUAI SOUTH-KAUAI SOUTHWEST-KIPAHULU-KOHALA-KONA-LANAI
LEEWARD-LANAI SOUTH-MAUI CENTRAL VALLEY SOUTH-MAUI LEEWARD WEST-
MOLOKAI LEEWARD SOUTH-MOLOKAI SOUTHEAST-NIIHAU-SOUTH HALEAKALA-
SOUTH MAUI/UPCOUNTRY-WAIANAE COAST.
SHORT TERM UPDATE...VAUGHAN
DISCUSSION...THOMAS
AVIATION...PIERCE
MARINE...TSAMOUS
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