483
FXHW60 PHFO 081913
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
913 AM HST SAT AUG 8 2026
SYNOPSIS
BREEZY TRADES WILL FOCUS LOW CLOUDS AND SHOWERS OVER WINDWARD AND
MAUKA AREAS THROUGH MID-NEXT WEEK. A PLUME OF MOISTURE MOVING
SOUTH OF THE ISLANDS WILL INCREASE RAIN CHANCES ACROSS THE EASTERN
END OF THE STATE THROUGH MONDAY, THEN DRIER CONDITIONS ARE EXPECTED
THROUGH MIDWEEK. BREWING WESTERN EAST PACIFIC DISTURBANCES WITHIN
THE TROPICS WILL NEED TO BE MONITORED FOR MORE ORGANIZED
DEVELOPMENT THE NEXT SEVERAL DAYS.
SHORT TERM UPDATE
SATELLITE IMAGERY SHOWS MOSTLY DRY CONDITIONS ACROSS THE WESTERN
HALF OF THE STATE THIS MORNING AND INCREASING LOW CLOUD AND SHOWER
COVERAGE OVER THE EASTERN END. THIS INCREASING MOISTURE BEGINNING
TO NUDGE INTO WINDWARD SLOPES OF THE BIG ISLAND IS A PART OF THE
LEADING EDGE OF A LARGER PLUME OF MOISTURE ASSOCIATED WITH A
WESTWARD-MOVING SURFACE TROUGH EXPECTED TO PASS SOUTH OF THE STATE
THIS WEEKEND. LOOKING ALOFT, A BROAD UPPER LEVEL TROUGH REMAINS
JUST TO THE NORTHWEST OF KAUAI AND IS CONTINUING TO SUPPLY SOME
THIN HIGH CLOUDS TO THE WESTERN HALF OF THE STATE THIS MORNING.
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT IN THE SHORT TERM,
SHOWING BREEZY TRADES PERSISTING THROUGH THE WEEKEND WITH LIMITED
SHOWERS MOVING INTO WINDWARD AND MAUKA AREAS OF THE WESTERN HALF
OF THE STATE TODAY, AND MORE SHOWERS CONCENTRATED OVER THE EASTERN
HALF AS THE PLUME OF MOISTURE MOVES IN.
PREV DISCUSSION
ISSUED AT 453 AM HST SAT AUG 8 2026
GENERALLY LIGHT TO BREEZY TRADES AS THE STATE FALLS IN BETWEEN A
1027 MB HIGH LOCATED OFF THE U.S. WEST COAST AND LOWER EQUATORIAL
PRESSURE. THICK MULTI-LAYERED CLOUD COVER STREAMING UP ALONG THE
EASTERN SIDE OF A WEAKENING WEST UPPER TROUGH WILL SPREAD WEST-
TO-EAST ACROSS THE ISLANDS TODAY. DESPITE THESE CLOUDS, THE
AFTERNOON WILL STILL WARM UP IN THE MIDDLE 80S TO AROUND 90 F
ACROSS MANY LOWER LYING SPOTS. TRADES WILL BE WELCOME AS WIND-
SHELTERED COASTAL AREAS FEEL THE MUGGIEST UNDER LOW 70 F DEW
POINTS. RECENT AREA SOUNDINGS DEPICT A DEEP AND MOIST ENOUGH
BOUNDARY LAYER THAT WILL BE ABLE TO SUPPORT CONTINUED WIDELY-
SCATTERED EASTERLY SHOWERS CAUGHT UP WITHIN MODERATE TRADE FLOW.
A MOIST EASTERLY AIR MASS IN ASSOCIATION WITH A TROPICAL WAVE OR
DISTURBANCE PASSING SOUTH OF THE ISLANDS NEAR 10N WILL INCREASE
CLOUD COVER AND INITIATE MORE LATE DAY THROUGH SUNDAY RAINFALL.
THE HIGHEST PROBABILITY OF PRECIPITATION IS FORECAST TO IMPACT THE
BIG ISLAND AND ITS SURROUNDING EASTERN AND SOUTHERN WATERS
TONIGHT THROUGH TOMORROW. LOCALLY HEAVY RAINFALL IS ALSO POSSIBLE.
IF ENOUGH EARLY DAY SUN HEATS UP MAUNA KEA AND MAUNA LOA'S
(PRIMARILY WESTERN) SLOPES, IN TANDEM WITH THE HIGHER MOISTURE
FLUX FROM THE SOUTH, THERE IS A MENTIONABLE CHANCE FOR AN ISOLATED
THUNDERSTORM OR TWO SUNDAY AFTERNOON. ONCE THIS SLUG OF SOUTHERN
MOISTURE ADVECTS WEST SOUTHWEST OF THE AREA TUESDAY, A DRIER AIR
MASS WILL BRIEFLY PASS THROUGH THE MIDDLE OF THE WEEK. THUS,
CLEARER SKIES ARE FORECAST TUESDAY THROUGH THURSDAY WITH LIMITED
SHOWER ACTIVITY. TRADES WILL NOT UNDERGO MUCH CHANGE SO THEY WILL
BE A RELIEF FROM WHAT WILL BE A FEW DAYS OF MUGGY, VERY WARM
WEATHER IN LOWER LYING, MORE WIND-PROTECTED COMMUNITIES.
THERE ARE INCREASING PROBABILITIES THAT AN EASTERLY WAVE NEAR
10N135W MAY DEVELOP A LOW CENTER AND STRENGTHEN INTO SOMETHING
MORE PAST 48 HOURS. PLEASE REFER TO THE LATEST NHC FORECASTS
CONCERNING THIS POTENTIAL EARLY TO MID NEXT WEEK EVOLUTION. THE
LATE WEEK FORECAST WILL BE DEPENDENT UPON THE STATE OF THE
TROPICS. THE MAJORITY OF THE NWP GUIDANCE, FROM DETERMINISTIC TO
ENSEMBLE SUITES TO AI, ARE LATCHING ON TO A MORE ACTIVE PATTERN
THIS TIME NEXT WEEK. MANY OF THE SOLUTIONS ARE LEANING TOWARD THE
DEVELOPMENT OF A TROPICAL CYCLONE FROM AN ACTIVE WESTERN EAST
PACIFIC REGION. WHILE STILL TOO EARLY TO DEFINITIVELY DISCUSS ANY
DETAILS OF A POTENTIAL TROPICAL CYCLONE, THIS ACTIVE AREA WILL
WARRANT CLOSE MONITORING THE NEXT FEW DAYS.
AVIATION
MODERATE TO FRESH TRADE WINDS WILL PREVAIL THROUGH THE WEEKEND.
MVFR CEILINGS WILL BE FOCUSED OVER TYPICAL WINDWARD SLOPES, BUT
WILL BE MORE EXTENSIVE OVER WINDWARD BIG ISLAND TODAY AS AN AREA
OF DEEPER MOISTURE MOVES IN ON THE TRADES. AIRMET SIERRA IS IN
EFFECT FOR WINDWARD BIG ISLAND AND WILL LIKELY BE EXPANDED
TONIGHT OR SUNDAY TO COVER WINDWARD BIG ISLAND, MAUI, AND MOLOKAI
AS THE ABOVE MENTIONED MOISTURE SPREADS WESTWARD. VFR CONDITIONS
WILL PREVAIL OVER MOST LEEWARD AREAS, THOUGH PORTIONS OF LEEWARD
BIG ISLAND COULD EXPERIENCE EXTENSIVE MVFR CONDITIONS WITH
SCATTERED HEAVY SHRA SUNDAY AFTERNOON.
AIRMET TANGO IS IN EFFECT FOR MOD TURB DOWNWIND OF ISLAND
TERRAIN. THIS AIRMET WILL LIKELY BE NEEDED FOR NEXT SEVERAL DAYS.
MARINE
FRESH TO LOCALLY STRONG TRADE WINDS WILL PERSIST THROUGH MOST OF
THE WEEK AS HIGH PRESSURE REMAINS ANCHORED NORTHEAST OF THE
STATE. A SMALL CRAFT ADVISORY HAS BEEN EXTENDED THROUGH SUNDAY
AFTERNOON FOR THE TYPICAL WINDY CHANNELS AND WATERS AROUND MAUI
COUNTY AND THE BIG ISLAND. THIS ADVISORY MANY NEED TO BE EXTENDED
FURTHER, AS BORDERLINE CONDITIONS WILL PREVAIL THROUGH AT LEAST
WEDNESDAY. LATE IN THE WEEK, THE FOCUS WILL SHIFT TO THE DEEP
TROPICS SOUTHEAST OF THE STATE, WHERE A TROPICAL CYCLONE COULD
DEVELOP.
A PAIR OF SOUTH-SOUTHWEST SWELLS WILL PRODUCE SOUTH SHORE SURF
NEAR AUGUST AVERAGE THIS WEEKEND AND NEAR TO ABOVE AVERAGE MONDAY
AND TUESDAY. A LARGER SWELL WILL ARRIVE TUESDAY NIGHT AND MAY
PUSH SURF TO THE HIGH SURF ADVISORY LEVEL LATE WEDNESDAY THROUGH
FRIDAY. THIS SWELL SHOULD SLOWLY DECREASE NEXT WEEKEND.
ALONG EAST-FACING SHORES, SHORT-PERIOD TRADE WIND SWELL WILL
GENERATE SURF JUST BELOW AUGUST AVERAGE THROUGH THURSDAY.
DEPENDING ON HOW POTENTIAL TROPICAL CYCLONE DEVELOPMENT PLAYS OUT
SOUTHEAST OF THE ISLANDS, AN INCREASE IN EAST SWELL IS POSSIBLE
FRIDAY AND NEXT WEEKEND. SURF ALONG NORTH-FACING SHORES WILL
REMAIN FLAT TO TINY THROUGH THE WEEK.
DUE TO A COMBINATION OF PEAK MONTHLY HIGH TIDES AND WATER LEVELS
RUNNING HIGHER THAN PREDICTED IN A FEW LOCATIONS, MINOR COASTAL
FLOODING WILL BE POSSIBLE AROUND THE AFTERNOON HIGH TIDE AS EARLY
AS SUNDAY, WITH PEAK CONDITIONS MONDAY THROUGH WEDNESDAY.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 PM HST SUNDAY FOR ALENUIHAHA
CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS-
MAALAEA BAY-PAILOLO CHANNEL.
SHORT TERM UPDATE...FARRIS
DISCUSSION...BLOOD
AVIATION...WROE
MARINE...WROE
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