034
FXHW60 PHFO 071939
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
939 AM HST TUE JUL 7 2026
SYNOPSIS
THE TIGHT PRESSURE GRADIENT DRAPED ACROSS THE ISLANDS, DRIVEN BY
AN AREA OF STRONG HIGH PRESSURE FAR NORTH OF THE STATE, WILL
CONTINUE TO PRODUCE BREEZY TO WINDY TRADES FOR THE REMAINDER OF
THE WEEK. SHOWERS WILL PRIMARILY FOCUS ALONG WINDWARD EXPOSURES AS
WELL AS ALONG UPSLOPE HIGHER TERRAIN. AN INCREASE IN SHOWER
COVERAGE AND FREQUENCY IS ANTICIPATED LATER THIS WEEK, WITH HIGHER
RAIN ACCUMULATIONS LIKELY OCCURRING DURING THE NOCTURNAL HOURS.
SHORT TERM UPDATE
THE CURRENT FORECAST REMAINS ON TRACK, WITH NO CHANGES MADE FOR
THIS MID MORNING UPDATE. RADAR AND VISIBLE SATELLITE IMAGERY SHOW
CLOUDS AND SHOWERS CONTINUING TO MOVE IN ON THE TRADES, WITH SOME
SPILLOVER TO LEEWARD AREAS AT TIMES. OVER THE LAST 6 HOURS, MOST
WINDWARD AND MAUKA AREAS ACROSS THE STATE HAVE RECEIVED A FEW
HUNDREDTHS TO A COUPLE OF TENTHS OF AN INCH OF RAIN, WITH THE
EXCEPTION OF THE BIG ISLAND WHERE RAIN GAGES ALONG THE NORTHEAST-
FACING COASTAL AREAS HAVE RECEIVED UP TO ABOUT AN INCH AND A HALF
OF RAIN. NOTHING TOO SIGNIFICANT, BUT NOTEWORTHY NONETHELESS.
SHOWER COVERAGE IS EXPECTED TO DECREASE SOME THROUGH THE DAY, AS
IS TYPICAL OF THE DIURNAL PATTERN IN TRADES, WITH SLIGHTLY MORE
MOISTURE FOCUSED OVER THE EASTERN END OF THE STATE. OTHERWISE,
BREEZY TO WINDY TRADES WILL CONTINUE.
PREV DISCUSSION
ISSUED AT 305 AM HST TUE JUL 7 2026
TRADE WINDS WILL REMAIN STOUT ACROSS MANY ISLAND COMMUNITIES THE
NEXT SEVERAL DAYS. THE WINDIEST SPOTS WILL BE OVER MOMENTUM-
BUILDING AREAS DOWNSLOPE OF HIGHER TERRAIN OR IN THE LEE OF BIG
ISLAND VOLCANOES SUCH AS MAUNA KEA THROUGH THE HAMAKUA AND KONA
REGIONS, THE SOUTHEASTERN WEST MAUI RANGE CLOSE TO THE NORTHWEST
MAALAEA BAY COAST, EXPOSED KALAUPAPA IN NORTH MOLOKAI, AS WELL
AS LEEWARD LOCALES JUST DOWNSLOPE OF HIGHER TERRAIN ON OAHU AND
WINDWARD KAUAI. WINDS OVER THESE AREAS OR THOSE SIMILAR IN WIND
EXPOSURE AND DOWNWIND OF HIGHER TERRAIN, HAVE REMAINED 25 MPH
SUSTAINED GUSTING TO NEAR 40 MPH. MORE FREQUENT LIGHT TO
OCCASIONALLY MODERATE INTENSITY SHOWERS WILL OCCUR ACROSS MANY
WINDWARD LOCATIONS WITH MORE ORGANIZED POCKETS OF RAIN BRIEFLY
SPILLING OVER INTO NEIGHBORING LEEWARD COMMUNITIES. THE SHORT TERM
RAINFALL FORECAST HAS THE HIGHEST QPF CENTERED ON THE WINDWARD
UPSLOPE UPPER TERRAIN OF BOTH MAUI AND BIG ISLAND THROUGH EARLY
WEDNESDAY MORNING.
THE CENTRAL PACIFIC UPPER AIR PATTERN REMAINS STAGNANT AS THE
STATE FALLS UNDER THE INFLUENCE OF A WEAK COL BETWEEN TWO
RELATIVELY WEAK CLOSED OFF LOWS. THIS SYNOPTIC SETUP OF THE
ISLANDS TRAPPED BETWEEN THESE TWO WEAK UPPER LOWS WITH AN
ANCHORED SURFACE HIGH FAR NORTH OF THE ISLAND CHAIN TRANSLATES TO
LITTLE TO NO CHANGE FOR THE REMAINDER OF THE WEEK. THUS, TRADES
WILL REMAIN AMPED UP WITH TYPICAL TRADE SHOWER BEHAVIOR. MODEL
GUIDANCE IS IN GOOD PHASE ALIGNMENT WITH THESE NEAR-STATIONARY
FEATURES ALONG WITH A BOUT OF ENHANCED MID LAYER MOISTURE
ADVECTION, POSSIBLY IN ASSOCIATION WITH A WEAK TROPICAL WAVE, THAT
WILL BEGIN ARRIVING THURSDAY AND PASSING OVER THE STATE THROUGH
SATURDAY. HIGHER-THAN-NORMAL PRECIPITABLE WATERS MOVING IN FROM
THE EAST LATER THIS WEEK SIGNALS A MORE WET PATTERN CHANGE. RAIN
COVERAGE AND HIGHER INTENSITY SHOWERS ENTRAINED WITHIN ROBUST
TRADES WILL RESULT IN HIGHER STATEWIDE RAIN ACCUMULATIONS FROM
THURSDAY INTO THE WEEKEND. THE TRADE INVERSION WILL WEAKEN,
DEEPENING A MORE MOIST BOUNDARY LAYER UPWARDS TO A DEPTH OF 10K FT
OR SLIGHTLY HIGHER. DEW POINTS TREADING IN THE LOWER 70S WILL BE
FELT IN INCREASED LATE WEEK SURFACE HUMIDITY. THE GOOD NEWS IS
THAT MORE MUGGY CONDITIONS WILL BE A BIT OFFSET BY ENHANCED
TRADES.
AVIATION
BREEZY TO LOCALLY WINDY TRADES WILL CONTINUE THROUGH WEDNESDAY
AND BRING LOW CLOUDS AND SCATTERED SHOWERS PREDOMINATELY TO
WINDWARD AND MOUNTAIN AREAS. THERE WILL ALSO BE ISOLATED SPILLOVER
INTO LEEWARD SITES. VFR WILL PREVAIL FOR MOST SITES, WITH
OCCASIONAL LOCALIZED MVFR MAINLY FOR WINDWARD/MOUNTAIN SITES
ASSOCIATED WITH THE STRONGER SHOWERS.
AIRMET TANGO REMAINS IN EFFECT FOR MODERATE LOW LEVEL TURBULENCE
OVER AND DOWNWIND OF TERRAIN FOR ALL ISLANDS. THIS AIRMET WILL
LIKELY CONTINUE THROUGH THE NEXT SEVERAL DAYS.
MARINE
A STRONG HIGH PRESSURE RIDGE CENTERED NORTH OF THE STATE WILL
HELP TO DRIVE FRESH TO STRONG TRADES ACROSS ALL LOCAL WATERS
THROUGH THIS AFTERNOON. A SMALL CRAFT ADVISORY (SCA) REMAINS IN
EFFECT FOR ALL WATERS THROUGH THIS AFTERNOON. WILL CONTINUE TO
MONITOR TO SEE IF SOME ZONES MAY DROP OUT OF THE SCA AS WINDS
SHIFT MORE EASTERLY AND DROP A NOTCH THIS EVENING.
A MODERATE, LONG PERIOD, SOUTH SOUTHWEST (190-200 DEGREES) SWELL
WILL CONTINUE TO GENERATE SURF ALONG SOUTH FACING SHORES JUST
BELOW ADVISORY LEVELS. THIS SWELL ENERGY WILL SLOWLY LOWER TODAY
THROUGH THE REMAINDER OF THE WEEK. EXPECT SMALL SURF FOR SOUTH
FACING SHORES LEADING INTO THIS WEEKEND WITH MAINLY BACKGROUND
ENERGY. ANOTHER MODERATE, LONG PERIOD SOUTH SOUTHWEST SWELL
(210-220 DEGREES) MAY FILL IN SUNDAY, BUT DUE TO THE DIRECTION OF
THE SOURCE, COULD BE MORE INCONSISTENT THAN THIS CURRENT SWELL.
SURF ALONG EAST FACING SHORES WILL REMAIN ROUGH AND CHOPPY
THROUGH THE WEEK AS FRESH TO STRONG TRADES HOLD. A SMALL, MODERATE
PERIOD WEST (280 DEGREES) SWELL IS EXPECTED TO ARRIVE THIS WEEKEND
AND LINGER INTO EARLY NEXT WEEK. NO SIGNIFICANT SWELLS ARE
EXPECTED OUT OF THE NORTH OR NORTHWEST.
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...FARRIS
DISCUSSION...BLOOD
AVIATION...PARKER
MARINE...FOSTER/VAUGHAN
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