993
FXHW60 PHFO 190206
AFDHFO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
406 PM HST MON AUG 18 2025
SYNOPSIS
MODERATE TO LOCALLY BREEZY TRADE WINDS WILL CONTINUE THROUGH THE
WEEK AS HIGH PRESSURE BUILDS OVER THE REGION BEHIND A DEPARTING
TROUGH. SCATTERED CLOUDS AND SHOWERS CONTINUE OVER THE WESTERN
HALF OF THE STATE TONIGHT, WITH PASSING WINDWARD AND MAUKA SHOWERS
ELSEWHERE. ANOTHER PLUME OF MOISTURE LOOKS TO BRING A SLIGHT
INCREASE IN WINDWARD AND MAUKA SHOWERS ON WEDNESDAY. OTHERWISE,
EXPECT A GRADUAL DRYING TREND THROUGH THE WEEK, WITH TYPICAL
SUMMERTIME TRADE WIND WEATHER (STABLE AND MOSTLY DRY CONDITIONS).
DISCUSSION
RADAR AND SATELLITE IMAGERY CONTINUE TO SHOW A WEAK SURFACE TROUGH
ASSOCIATED WITH THE REMNANTS OF FORMER TROPICAL CYCLONE IVO MOVING
ACROSS THE WESTERN HALF OF THE STATE THIS AFTERNOON. WILL CONTINUE
TO SEE SCATTERED CLOUDS AND SHOWERS THROUGH TONIGHT OVER PARTS OF
THE WESTERN ISLANDS, WITH ISOLATED WINDWARD AND MAUKA SHOWERS
ELSEWHERE.
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE HAWAIIAN ISLAND
TONIGHT AS THE TROUGH DEPARTS TO THE WEST, WITH MODERATE TO
LOCALLY BREEZY TRADE WINDS CONTINUING THROUGH THE WEEK. WILL
CONTINUE TO SEE DRIER AIR FILTER INTO THE REGION FROM THE EAST
LATE TONIGHT, WITH LESS CLOUDS AND SHOWERS EXPECTED ON TUESDAY.
GUIDANCE CONTINUES TO SHOW ANOTHER PLUME OF MOISTURE MOVING ACROSS
THE ISLANDS ON WEDNESDAY WHICH MAY BRING A SLIGHT INCREASE IN
CLOUDS AND SHOWERS OVER WINDWARD AND MAUKA AREAS. OTHERWISE, THE
GRADUAL DRYING TREND WILL CONTINUE THROUGH THE WEEK WITH TYPICAL
SUMMERTIME TRADE WIND WEATHER EXPECTED UNDER DRY AND STABLE
CONDITIONS. WITH DRY AND BREEZY CONDITIONS EXPECTED LATER THIS
WEEK WE WILL SEE ELEVATED FIRE WEATHER CONCERNS, ESPECIALLY ACROSS
LEEWARD AREAS. FOR MORE DETAILS SEE THE FIRE WEATHER SECTION
BELOW.
AVIATION
MODERATE TO LOCALLY BREEZY TRADES ARE EXPECTED THROUGH THE
FORECAST PERIOD. PERIODS OF LOW CIGS AND SHRA ARE POSSIBLE OVER
WINDWARD AND MAUKA AREAS OVERNIGHT PROMPTING BRIEF MVFR CONDS.
OTHERWISE, VFR CONDS WILL PREVAIL.
NO AIRMETS ARE IN EFFECT AT THIS TIME. AIRMET SIERRA MAY BE
NEEDED OVERNIGHT DUE TO POTENTIAL INCREASES IN LOW CLOUDS AND SHRA
ALONG WINDWARD AND MAUKA REGIONS. AIRMET TANGO MAY BE ISSUED IF
LOW LEVEL WIND SPEEDS INCREASE TOMORROW.
MARINE
A RIDGE OF HIGH PRESSURE FAR NORTH OF THE STATE WILL HELP MAINTAIN
FRESH TO LOCALLY STRONG TRADE WINDS THROUGHOUT THE WEEK. A SMALL
CRAFT ADVISORY (SCA) FOR THE TYPICAL WINDY WATERS AROUND MAUI AND
THE BIG ISLAND REMAINS IN EFFECT AND WILL LIKELY PERSIST
THROUGHOUT THE WEEK.
A SERIES OF SMALL, MEDIUM PERIOD SOUTH (170-190 DEGREE) SWELLS
ARE EXPECTED THROUGHOUT THE WEEK WITH SURF HOLDING NEAR THE SUMMER
AVERAGE. SURF HEIGHTS SHOULD DECREASE SUNDAY INTO EARLY NEXT WEEK
AS THESE SWELLS FADE. CHOPPY CONDITIONS WILL CONTINUE FOR EAST-
FACING SHORES THROUGH THE FORECAST PERIOD DUE TO THE PERSISTENT
FRESH TRADES. MEANWHILE, EXPECT SURF TO BE FLAT TO TINY ALONG
NORTH FACING SHORES.
PEAK MONTHLY HIGH TIDES COMBINED WITH WATER LEVELS THAT ARE
RUNNING HIGHER THAN PREDICTED WILL LEAD TO MINOR FLOODING ALONG
THE SHORELINE AND IN LOW-LYING COASTAL AREAS STARTING AS EARLY AS
TUESDAY AFTERNOON AND LIKELY PEAKING WEDNESDAY AND THURSDAY
AFTERNOONS. COASTAL FLOODING IS POSSIBLE AROUND THE DAILY PEAK
TIDE, WHICH WILL BE DURING THE AFTERNOON HOURS. A COASTAL FLOOD
STATEMENT HAS BEEN ISSUED FOR MINOR COASTAL FLOODING THIS WEEK.
FIRE WEATHER
MODERATE TO LOCALLY BREEZY TRADE WINDS EXPECTED THIS WEEK AS HIGH
PRESSURE BUILDS OVER THE STATE BEHIND A DEPARTING TROUGH.
BORDERLINE FIRE WEATHER CONDITIONS POSSIBLE ON TUESDAY AS DRIER
AIR STARTS TO FILTER INTO THE REGION. ANOTHER PLUME OF MOISTURE
MAY BRING A SLIGHT INCREASE IN HUMIDITY AND SHOWERS ON WEDNESDAY.
ELEVATED FIRE WEATHER CONDITIONS POSSIBLE BEYOND WEDNESDAY AS
STABLE AND DRIER CONDITIONS DEVELOP AND THE TRADE WIND INVERSION
LOWERS TO AROUND 5000-6000 FEET. BREEZY TRADE WINDS AND AFTERNOON
RELATIVE HUMIDITY IN THE UPPER 40S TO LOWER 50S MAY REQUIRE FIRE
WEATHER HEADLINES TO BE ISSUED IN THE COMING DAYS. STAY TUNED FOR
DETAILS.
HFO WATCHES/WARNINGS/ADVISORIES
SMALL CRAFT ADVISORY UNTIL 6 AM HST WEDNESDAY FOR MAALAEA BAY-
PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG
ISLAND SOUTHEAST WATERS.
DISCUSSION...AHUE
AVIATION...DT
MARINE...KINO
FIRE WEATHER...AHUE
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